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# Generated by nginxconfig.io | |
# See nginxconfig.txt for the configuration share link | |
# Note in comments by Harisfazillah Jamel and Google Gemini | |
# 15 Jun 2025 | |
user www-data; | |
pid /run/nginx.pid; | |
worker_processes auto; | |
worker_rlimit_nofile 65535; | |
# Load modules | |
include /etc/nginx/modules-enabled/*.conf; | |
events { | |
multi_accept on; | |
worker_connections 65535; | |
} | |
http { | |
charset utf-8; | |
sendfile on; | |
tcp_nopush on; | |
tcp_nodelay on; | |
server_tokens off; | |
types_hash_max_size 2048; | |
types_hash_bucket_size 64; | |
client_max_body_size 16M; | |
# MIME | |
include mime.types; | |
default_type application/octet-stream; | |
# Log Format | |
log_format cloudflare '$remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" $http_cf_ray $http_cf_connecting_ip $http_x_forwarded_for $http_x_forwarded_proto $http_true_client_ip $http_cf_ipcountry $http_cf_visitor $http_cdn_loop'; | |
# Logging | |
access_log off; | |
error_log /var/log/nginx/error.log warn; | |
# Limits | |
limit_req_log_level warn; | |
limit_req_zone $binary_remote_addr zone=login:10m rate=10r/m; | |
# SSL | |
ssl_session_timeout 1d; | |
ssl_session_cache shared:SSL:10m; | |
ssl_session_tickets off; | |
# Mozilla Modern configuration | |
ssl_protocols TLSv1.3; | |
# OCSP Stapling | |
ssl_stapling on; | |
ssl_stapling_verify on; | |
resolver 1.1.1.1 1.0.0.1 [2606:4700:4700::1111] [2606:4700:4700::1001] 8.8.8.8 8.8.4.4 [2001:4860:4860::8888] [2001:4860:4860::8844] 208.67.222.222 208.67.220.220 [2620:119:35::35] [2620:119:53::53] 9.9.9.9 149.112.112.112 [2620:fe::fe] [2620:fe::9] 64.6.64.6 64.6.65.6 [2620:74:1b::1:1] [2620:74:1c::2:2] valid=60s; | |
resolver_timeout 2s; | |
# Connection header for WebSocket reverse proxy | |
map $http_upgrade $connection_upgrade { | |
default upgrade; | |
"" close; | |
} | |
map $remote_addr $proxy_forwarded_elem { | |
# IPv4 addresses can be sent as-is | |
~^[0-9.]+$ "for=$remote_addr"; | |
# IPv6 addresses need to be bracketed and quoted | |
~^[0-9A-Fa-f:.]+$ "for=\"[$remote_addr]\""; | |
# Unix domain socket names cannot be represented in RFC 7239 syntax | |
default "for=unknown"; | |
} | |
map $http_forwarded $proxy_add_forwarded { | |
# If the incoming Forwarded header is syntactically valid, append to it | |
"~^(,[ \\t]*)*([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?(;([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?)*([ \\t]*,([ \\t]*([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?(;([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?)*)?)*$" "$http_forwarded, $proxy_forwarded_elem"; | |
# Otherwise, replace it | |
default "$proxy_forwarded_elem"; | |
} | |
# --- NGINX CACHE CONFIGURATION START --- | |
# Define a cache zone named 'my_cache' | |
# Keys will be stored in memory (10m) | |
# Total cache size will be 1g | |
# Inactive items will be removed after 60m | |
# Cache directory: /var/cache/nginx | |
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m max_size=1g inactive=60m use_temp_path=off; | |
# --- NGINX CACHE CONFIGURATION END --- | |
# Load configs | |
include /etc/nginx/conf.d/*.conf; | |
# linuxmalaysia.com | |
server { | |
listen 443 ssl reuseport; | |
listen [::]:443 ssl reuseport; | |
http2 on; | |
server_name linuxmalaysia.com; | |
root /var/www/linuxmalaysia.com/public; | |
# SSL | |
ssl_certificate /etc/nginx/ssl/linuxmalaysia.com.crt; | |
ssl_certificate_key /etc/nginx/ssl/linuxmalaysia.com.key; | |
# security headers | |
add_header X-XSS-Protection "1; mode=block" always; | |
add_header X-Content-Type-Options "nosniff" always; | |
add_header Referrer-Policy "no-referrer-when-downgrade" always; | |
add_header Content-Security-Policy "default-src 'self' http: https: ws: wss: data: blob: 'unsafe-inline'; frame-ancestors 'self';" always; | |
add_header Permissions-Policy "interest-cohort=()" always; | |
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always; | |
# . files | |
location ~ /\.(?!well-known) { | |
deny all; | |
} | |
# security.txt | |
location /security.txt { | |
return 301 /.well-known/security.txt; | |
} | |
location = /.well-known/security.txt { | |
alias ~/security.txt; | |
} | |
# restrict methods | |
if ($request_method !~ ^(GET|POST|PUT|HEAD|CONNECT)$) { | |
return '405'; | |
} | |
# logging | |
access_log /var/log/nginx/access.log combined buffer=512k flush=1m; | |
error_log /var/log/nginx/error.log warn; | |
# reverse proxy | |
location / { | |
proxy_pass http://127.0.0.1:3000; | |
proxy_set_header Host $host; | |
proxy_http_version 1.1; | |
proxy_cache_bypass $http_upgrade; | |
# --- NGINX CACHE APPLICATION START --- | |
proxy_cache my_cache; # Use the defined cache zone | |
proxy_cache_valid 200 302 10m; # Cache successful responses for 10 minutes | |
proxy_cache_valid 404 1m; # Cache 404 responses for 1 minute | |
proxy_cache_key "$scheme$proxy_host$request_uri"; # Define the cache key | |
proxy_cache_min_uses 1; # Cache after 1 request | |
proxy_cache_revalidate on; # Revalidate stale content | |
proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504; # Serve stale content on errors | |
# Add header to see if content is served from cache (optional, for debugging) | |
add_header X-Cache-Status $upstream_cache_status; | |
# --- NGINX CACHE APPLICATION END --- | |
# Proxy SSL | |
proxy_ssl_server_name on; | |
# Proxy headers | |
proxy_set_header Upgrade $http_upgrade; | |
proxy_set_header Connection $connection_upgrade; | |
proxy_set_header X-Real-IP $remote_addr; | |
proxy_set_header Forwarded $proxy_add_forwarded; | |
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; | |
proxy_set_header X-Forwarded-Proto $scheme; | |
proxy_set_header X-Forwarded-Host $host; | |
proxy_set_header X-Forwarded-Port $server_port; | |
# Proxy timeouts | |
proxy_connect_timeout 60s; | |
proxy_send_timeout 60s; | |
proxy_read_timeout 60s; | |
} | |
# favicon.ico | |
location = /favicon.ico { | |
log_not_found off; | |
} | |
# robots.txt | |
location = /robots.txt { | |
log_not_found off; | |
} | |
# # assets, media | |
# location ~* \.(?:css(\.map)?|js(\.map)?|jpe?g|png|gif|ico|cur|heic|webp|tiff?|mp3|m4a|aac|ogg|midi?|wav|mp4|mov|webm|mpe?g|avi|ogv|flv|wmv)$ { | |
# expires 7d; | |
# } | |
# | |
# # svg, fonts | |
# location ~* \.(?:svgz?|ttf|ttc|otf|eot|woff2?)$ { | |
# add_header Access-Control-Allow-Origin "*"; | |
# expires 7d; | |
# } | |
# gzip | |
gzip on; | |
gzip_vary on; | |
gzip_proxied any; | |
gzip_comp_level 6; | |
gzip_types text/plain text/css text/xml application/json application/javascript application/rss+xml application/atom+xml image/svg+xml; | |
} | |
# HTTP redirect | |
server { | |
listen 80 reuseport; | |
listen [::]:80 reuseport; | |
server_name linuxmalaysia.com; | |
# logging | |
access_log /var/log/nginx/access.log combined buffer=512k flush=1m; | |
error_log /var/log/nginx/error.log warn; | |
return 301 https://linuxmalaysia.com$request_uri; | |
} | |
} |
Nginx Cache Configuration: proxy_cache_path
Explained
You're asking about the proxy_cache_path
directive, which is the foundational setting for enabling and managing caching in Nginx when it acts as a reverse proxy. This directive defines a cache zone, telling Nginx where to store cached content and how to manage it.
Let's break down each part of this crucial line:
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m max_size=1g inactive=60m use_temp_path=off;
1. /var/cache/nginx
- Explanation: This is the path to the root directory where Nginx will store its cache files on your server's file system.
- Performance Impact:
- Disk I/O: The performance of your cache heavily depends on the speed of the disk where this directory resides. An SSD (Solid State Drive) will offer significantly better read/write performance for caching compared to a traditional HDD (Hard Disk Drive).
- Permissions: Nginx's worker processes (running as
www-data
in your setup) must have write access to this directory to create and store cache files. If permissions are incorrect, caching will fail.
- Suggestions:
- Ensure this directory exists (
sudo mkdir -p /var/cache/nginx
). - Set appropriate ownership and permissions (
sudo chown -R www-data:www-data /var/cache/nginx
). - If possible, place this on a fast local disk (SSD is ideal).
- Ensure this directory exists (
2. levels=1:2
- Explanation: This defines the directory hierarchy for the cache. Nginx stores cache files in a structured way to avoid having too many files in a single directory, which can be inefficient for the file system.
1:2
means Nginx will create two levels of subdirectories based on the MD5 hash of the cache key.- The first level will have 1 character (0-F).
- The second level will have 2 characters (00-FF).
- For example, a cached file might be stored at
/var/cache/nginx/c/29/abcdef12345...
.
- Performance Impact:
- File System Efficiency: This is crucial for performance with large caches. Without proper directory levels, a single directory could contain millions of files, leading to slow lookups and I/O operations for the operating system.
- Optimal Setting:
levels=1:2
is a standard and highly recommended setting for good performance, balancing directory depth with the number of subdirectories.
- Suggestions: Stick with
levels=1:2
. Rarely needs adjustment.
3. keys_zone=my_cache:10m
- Explanation: This defines a shared memory zone for storing the cache keys and metadata (like HTTP headers) for all active cached items.
my_cache
: This is the name of your cache zone. You'll use this name inproxy_cache my_cache;
directives within yourlocation
blocks to enable caching.10m
: Specifies the size of this shared memory zone in megabytes. Each entry (cache key and metadata) typically takes around 64-128 bytes. A10m
zone can hold metadata for roughly 80,000 to 160,000 active cached items.
- Performance Impact (Memory & CPU):
- Memory Consumption: This directly allocates 10MB of RAM that is shared among all Nginx worker processes.
- CPU (Lookup Speed): This zone acts as an in-memory index for your disk cache. When a request comes in, Nginx first checks this fast in-memory hash table. If a match is found (a "cache hit"), Nginx knows where to find the file on disk. This significantly reduces CPU cycles and latency compared to having to search the disk every time.
- Cache Efficiency: If this zone is too small for the number of items you frequently cache, Nginx might have to evict entries prematurely from the memory index, even if the content is still on disk, leading to more "misses" and disk lookups.
- Suggestions:
10m
is a good starting point forkeys_zone
.- Monitor: If Nginx logs warnings about the
keys_zone
being full or cache "overflows," you might need to increase this size. The amount of memory used here should align with the number of unique URLs you expect to cache.
4. max_size=1g
- Explanation: This directive sets the maximum size of the disk cache. Once the cache grows beyond this limit, Nginx will start removing the least recently used (LRU) files to free up space.
1g
: Specifies a maximum cache size of 1 gigabyte.
- Performance Impact (Disk Space & Efficiency):
- Disk Usage: Directly controls how much disk space your cache consumes.
- Cache Hit Ratio: A larger
max_size
allows Nginx to store more content, potentially leading to a higher cache hit ratio (meaning more requests are served from cache, reducing backend load). - Eviction Overhead: When the
max_size
is reached, Nginx's cache manager process starts deleting old files. This process consumes some CPU and disk I/O, but it's typically efficient and runs in the background.
- Suggestions:
- Based on Disk Space: Choose a size appropriate for your available disk space.
- Based on Content Volume: Consider the total size of the static and dynamic content you expect to cache. For many websites, 1GB is a decent start. Larger sites with lots of images or media might need 10GB, 50GB, or even more.
5. inactive=60m
- Explanation: This directive specifies how long a cached item can remain in the cache without being accessed. If an item is not requested for
60m
(60 minutes), it will be removed by the cache manager process, regardless of whether themax_size
has been reached. - Performance Impact (Disk Space & Freshness):
- Disk Space Management: Helps to automatically free up disk space from stale or unpopular content.
- Cache Freshness: Prevents your cache from filling up with old content that is no longer frequently requested.
- CPU: The cache manager process runs periodically to check for inactive items, consuming minimal CPU.
- Suggestions:
60m
(1 hour) is a common and usually good value.- Adjust based on content volatility:
- If your content changes frequently, you might reduce this (e.g.,
30m
). - If your content is very stable and rarely changes, you could increase it (e.g.,
1d
or7d
) to keep items in cache longer and potentially improve hit rates for less frequent visitors.
- If your content changes frequently, you might reduce this (e.g.,
6. use_temp_path=off;
- Explanation: This directive is highly recommended for performance. By default, Nginx first writes cached files to a temporary file in a separate
proxy_temp_path
directory (often/var/lib/nginx/tmp
), then renames it to the cache directory.use_temp_path=off;
prevents this. - Performance Impact (Disk I/O & CPU):
- Reduced Disk I/O: When
off
, Nginx writes directly to the cache directory. This avoids an extra disk write (to temp) and a rename operation, significantly reducing disk I/O, especially on busy servers or those using SSDs. This is a crucial optimization. - CPU: Reduces CPU overhead associated with file copying and renaming.
- Atomicity: While
off
is great for performance, be aware that if the Nginx process crashes while writing a file, a partial file might be left in the cache directory. However, Nginx is generally stable, and the performance gain usually outweighs this minor risk.
- Reduced Disk I/O: When
- Suggestions: Always keep
use_temp_path=off;
unless you have a very specific reason not to (e.g., extreme concern about partial files after a crash on a highly sensitive system, which is rare).
CPU and Memory Considerations for proxy_cache_path
- CPU: The CPU impact comes from hash lookups in
keys_zone
, background cache management (inactive item removal, LRU eviction), and the overhead of writing files to disk.sendfile on;
(in thehttp
block) helps significantly reduce CPU when serving cached content. - Memory:
- The
keys_zone
directly consumes the specified amount of RAM (10m
in your case). This memory is pre-allocated. - Nginx also uses some memory for buffering requests and responses, but
proxy_cache_path
directly relates to the shared memory cache for its index.
- The
- Overall: Your
proxy_cache_path
configuration is very well-tuned for general web serving, balancing memory usage, disk space, and performance. Theuse_temp_path=off
is a particularly important optimization.
By having this cache configured, you enable Nginx to serve content much faster, reduce the load on your backend application, and improve the overall responsiveness of your website for visitors in Cyberjaya, Selangor, Malaysia, and globally.
Let's dive into the location /
block of your Nginx configuration, which is where the magic of reverse proxying and caching for your main application happens. This block is critical as it defines how Nginx handles all requests that don't match more specific location
directives (like those for static assets).
Reverse Proxying Directives
These lines tell Nginx to forward requests to your backend application:
-
proxy_pass http://127.0.0.1:3000;
- Explanation: This is the core of the reverse proxy. It tells Nginx to forward all requests matching this
location
block to your backend server running onhttp://127.0.0.1:3000
. So, when someone visitslinuxmalaysia.com
, Nginx fetches the content from your application and serves it back to the user. - Performance Impact: This enables your web application to be served by Nginx, which is more efficient at handling connections and static content than most application servers. It allows you to run your application server on a private port, increasing security.
- Explanation: This is the core of the reverse proxy. It tells Nginx to forward all requests matching this
-
proxy_set_header Host $host;
- Explanation: This sets the
Host
header that Nginx sends to your backend.$host
is an Nginx variable that automatically resolves to the incomingHost
header from the client (e.g.,linuxmalaysia.com
). Without this, your backend might receiveHost: 127.0.0.1:3000
, which could cause issues if your application relies on the original hostname (e.g., for routing or virtual hosting). - Performance Impact: Ensures your application functions correctly, preventing errors or misconfigurations that would degrade performance or availability.
- Explanation: This sets the
-
proxy_http_version 1.1;
- Explanation: This sets the HTTP version used for the connection between Nginx and your backend server. HTTP/1.1 supports persistent connections (
Keep-Alive
). - Performance Impact: Important for keeping the connection to your backend alive for multiple requests, reducing the overhead of establishing new TCP connections for every request. This improves efficiency and reduces latency, especially for dynamic applications.
- Explanation: This sets the HTTP version used for the connection between Nginx and your backend server. HTTP/1.1 supports persistent connections (
-
proxy_cache_bypass $http_upgrade;
- Explanation: This directive tells Nginx not to serve from cache if the request contains the
$http_upgrade
header. This is essential for WebSocket connections. When a browser tries to upgrade a connection to a WebSocket, Nginx needs to pass that request directly to the backend without trying to serve it from cache, as WebSockets are real-time, non-cacheable connections. - Performance Impact: Ensures correct functionality for WebSockets and other upgrade protocols, preventing broken connections. It's a specialized directive for maintaining the integrity of such connections.
- Explanation: This directive tells Nginx not to serve from cache if the request contains the
Nginx Cache Application Directives
These lines enable and configure the caching behavior for the content served through this location
block:
-
proxy_cache my_cache;
- Explanation: This is the directive that activates caching for this
location
block. It references themy_cache
zone you defined earlier withproxy_cache_path
. All responses from your backend for requests handled by thislocation
will attempt to be cached in themy_cache
zone. - Performance Impact: This is the primary driver of performance improvement. Once content is cached, Nginx can serve it directly from disk (or even memory, via kernel buffers), bypassing your backend application entirely for subsequent requests. This drastically reduces backend load, CPU, memory, and database usage, leading to much faster response times.
- Explanation: This is the directive that activates caching for this
-
proxy_cache_valid 200 302 10m;
- Explanation: This specifies that successful HTTP responses (status codes
200 OK
and302 Found
) should be cached for10m
(10 minutes). After 10 minutes, the cached entry becomes "stale" and Nginx will revalidate it with the backend. - Performance Impact: Controls the freshness of your cached content. Longer validity times increase cache hit rates (more performance benefit) but mean content might be slightly less fresh.
- Suggestion: Adjust this based on how frequently your content changes. For highly dynamic content, you might use a shorter time (e.g.,
1m
or5m
). For mostly static pages from your application,10m
is reasonable.
- Explanation: This specifies that successful HTTP responses (status codes
-
proxy_cache_valid 404 1m;
- Explanation: This tells Nginx to cache
404 Not Found
responses for1m
(1 minute). - Performance Impact: This is a great optimization for reducing load from "bad" requests or bots probing your server for non-existent pages. Instead of hitting your backend for every 404, Nginx can serve the cached 404 response directly for a short period.
- Suggestion: Keep this. It helps protect your backend from excessive requests for invalid URLs.
- Explanation: This tells Nginx to cache
-
proxy_cache_key "$scheme$proxy_host$request_uri";
- Explanation: This defines the unique key used to store and retrieve items from the cache.
$scheme
: The protocol (http
orhttps
).$proxy_host
: TheHost
header sent to the backend (your domain name).$request_uri
: The full request URI (path + query string, e.g.,/articles/nginx?id=123
).
- Performance Impact: Ensures that different URLs (or the same URL requested over HTTP vs. HTTPS) are cached as distinct items. This is crucial for correct cache behavior. Using a comprehensive key maximizes the likelihood of caching the correct content.
- Suggestion: This is a standard and robust cache key. Stick with it unless you have very specific caching needs (e.g., excluding certain query parameters).
- Explanation: This defines the unique key used to store and retrieve items from the cache.
-
proxy_cache_min_uses 1;
- Explanation: This directive specifies that a response will be cached only after it has been requested
1
time. - Performance Impact: For
1
, it means content is cached on the very first request. This maximizes caching benefits immediately. If you set it higher (e.g.,proxy_cache_min_uses 2;
), an item would only be cached after being requested twice, which might be useful if you only want to cache truly popular items to save disk space, but it delays the caching benefit. - Suggestion: For most websites,
1
is good, as it provides immediate caching benefits.
- Explanation: This directive specifies that a response will be cached only after it has been requested
-
proxy_cache_revalidate on;
- Explanation: When a cached item becomes stale, Nginx will send a conditional request to the backend (using
If-Modified-Since
andIf-None-Match
headers). If the content hasn't changed, the backend can respond with a304 Not Modified
status, telling Nginx that its cached version is still valid, thus avoiding sending the full content again. - Performance Impact: Reduces bandwidth usage and backend CPU/memory by avoiding full content transfers when content hasn't changed. This is very efficient for refreshing stale content.
- Suggestion: Keep
on
. This is a significant optimization.
- Explanation: When a cached item becomes stale, Nginx will send a conditional request to the backend (using
-
proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
- Explanation: This directive is a powerful feature for maintaining high availability. If Nginx tries to revalidate a cached item or fetch a new one from the backend, and the backend returns any of the specified errors (
error
,timeout
,updating
,http_500
,http_502
,http_503
,http_504
), Nginx will serve the stale (expired) content from its cache instead of returning an error to the client.error
: General proxying errors.timeout
: Backend connection or read timeout.updating
: Nginx is currently updating the cache for this item from the backend.http_500
,http_502
,http_503
,http_504
: Specific HTTP error codes from the backend.
- Performance Impact (Availability & User Experience): This significantly improves user experience during backend outages or temporary slowdowns. Users will still see content (even if slightly outdated) instead of an error page, greatly improving the perceived uptime and reliability of your service. It's a form of graceful degradation.
- Suggestion: Keep this as is. It's an excellent resilience feature.
- Explanation: This directive is a powerful feature for maintaining high availability. If Nginx tries to revalidate a cached item or fetch a new one from the backend, and the backend returns any of the specified errors (
-
add_header X-Cache-Status $upstream_cache_status;
- Explanation: This adds a custom HTTP header to the response, indicating whether the content was served from the cache (
HIT
,MISS
,EXPIRED
,STALE
, etc.).$upstream_cache_status
is a built-in Nginx variable. - Performance Impact: Has a negligible performance impact.
- Suggestion: This is purely for debugging and monitoring. It's incredibly useful during development and initial deployment to verify that your caching is working as expected. You can remove it in production if you don't need this information directly in the response headers.
- Explanation: This adds a custom HTTP header to the response, indicating whether the content was served from the cache (
Overall Impact on Nginx Performance (CPU and Memory)
This location
block, especially the caching directives, significantly offloads your backend application and improves performance:
- CPU:
- Reduced Backend CPU: The biggest win is the massive reduction in CPU cycles on your backend application, as Nginx serves cached content without even touching it.
- Nginx CPU: Nginx will use some CPU for cache lookups, file serving (especially with
sendfile
), and background cache management. However, this is typically much less than the CPU your application would use to generate the content.
- Memory:
- Reduced Backend Memory: Your backend application will use less memory as it processes fewer requests.
- Nginx Memory: Nginx will use memory for the
keys_zone
(already accounted for) and for buffering requests/responses. Theproxy_cache_valid
andproxy_cache_use_stale
settings don't directly consume more memory but dictate what gets stored in the disk cache (which has its ownmax_size
limit).
This is a very well-configured proxy and cache setup. It strikes a good balance between performance, content freshness, and resilience.
Nginx Gzip Compression Settings
Let's break down your Nginx Gzip compression settings. These directives are vital for optimizing your website's performance by reducing the size of text-based responses sent to browsers, leading to faster load times and lower bandwidth consumption.
1. gzip on;
- Explanation: This is the master switch that enables Gzip compression in Nginx. If this is off, all other
gzip_
directives related to compression won't have any effect. - Performance Impact: When enabled, Nginx will compress eligible files (based on
gzip_types
) before sending them to the client. This significantly reduces the size of data transmitted over the network.- CPU: Compression consumes CPU cycles on the Nginx server.
- Bandwidth: Drastically reduces the amount of data transferred, which is a major benefit, especially for users on slower connections or with limited data plans (like mobile users).
- Latency: Faster downloads lead to lower perceived latency and quicker page load times for users in Cyberjaya and beyond.
- Suggestion: Keep
on
. It's a fundamental performance optimization.
2. gzip_vary on;
- Explanation: This directive tells Nginx to add a
Vary: Accept-Encoding
header to responses that have been compressed. This header instructs proxy servers (like CDNs or ISP caches) and browsers to cache two separate versions of the resource: one compressed and one uncompressed. This is crucial because not all clients support Gzip compression. - Performance Impact:
- Correct Caching: Prevents proxies from serving a compressed version to a client that doesn't support Gzip, or an uncompressed version to a client that expects Gzip. This ensures the correct content is delivered to the right client.
- Proxy Efficiency: Helps intermediate caches work more effectively, serving the appropriate version to various clients, which further speeds up delivery.
- Suggestion: Keep
on
. It's best practice for efficient caching and compatibility.
3. gzip_proxied any;
- Explanation: This directive controls whether Nginx should compress responses for requests that originated from a proxy server.
any
: Nginx will compress responses for all proxied requests, regardless of the request's headers (likeVia
,X-Forwarded-For
, etc.).
- Performance Impact:
- Comprehensive Compression: Ensures that compression benefits apply even when Nginx is behind another proxy (e.g., a load balancer or another CDN layer), as is common in complex infrastructures.
- Reduced Traffic Between Proxies: If Nginx is serving compressed content to an upstream proxy, it reduces the data transferred between Nginx and that proxy, saving bandwidth and improving speed within your infrastructure.
- Suggestion: Keep
any
. It maximizes the benefits of Gzip compression across your entire delivery chain.
4. gzip_comp_level 6;
- Explanation: This sets the Gzip compression level. The levels range from 1 (fastest compression, least reduction in size) to 9 (slowest compression, greatest reduction in size).
6
: This is a good balance between compression ratio and CPU usage. It offers a decent size reduction without placing an excessive burden on the server's CPU.
- Performance Impact:
- CPU: Higher compression levels (e.g., 7-9) consume more CPU to compress the data, but might yield slightly smaller file sizes. Lower levels (e.g., 1-3) use less CPU but result in larger files.
- Bandwidth: A higher compression level means smaller files, reducing bandwidth usage.
- Latency: The trade-off is between the CPU time spent on compression and the time saved by downloading a smaller file. For most web content, level 6 often represents the "sweet spot." Beyond level 6, the gains in compression ratio typically diminish, while CPU usage continues to rise.
- Suggestion:
6
is an excellent choice. You could experiment with5
if you notice high CPU usage during compression, or7
if you prioritize minimal file size over a slight increase in CPU. For most dynamic web content, the difference in file size between 6 and 9 is often negligible for the increased CPU cost.
5. gzip_types text/plain text/css text/xml application/json application/javascript application/rss+xml application/atom+xml image/svg+xml;
- Explanation: This directive specifies the MIME types of responses that Nginx should compress. Only responses with these
Content-Type
headers will be Gzipped. - Performance Impact:
- Targeted Compression: Ensures that only compressible content (text-based) is compressed. Binary files like JPEGs, PNGs, MP4s, etc., are usually already compressed by their native formats, and trying to Gzip them would be a waste of CPU cycles (they'd get very little, if any, additional compression, and might even increase in size in rare cases).
- Efficiency: Reduces unnecessary CPU consumption by not attempting to compress already-compressed or incompressible data.
- Suggestion:
- Your list is comprehensive and covers the most common compressible web assets.
- You might consider adding
application/x-javascript
if you have older JavaScript files that use that MIME type, thoughapplication/javascript
is standard now. - Also common to add
font/ttf font/opentype application/x-font-woff application/font-woff2
if you're serving fonts directly and they're not already highly compressed. image/svg+xml
is correctly included, as SVG files are XML-based text files and compress very well.
Overall Impact on Nginx Performance (CPU and Memory)
- CPU: Gzip compression directly consumes CPU resources. The
gzip_comp_level
plays the biggest role here. However, the CPU saved by faster network transfers and reduced bandwidth often outweighs the CPU cost of compression. - Memory: Nginx uses a small amount of memory for buffering during the compression process. This is generally not a major concern unless you're serving extremely large, compressible files to a massive number of concurrent users.
- Bandwidth: This is where Gzip shines. It significantly reduces bandwidth usage, which can save on hosting costs and provide a much better experience for users, especially on metered or slower connections.
Your Gzip configuration is well-optimized. It's a standard and effective setup that balances CPU usage with substantial bandwidth and latency improvements, making your site load faster for visitors.
Nginx Security Headers Explained
You've included a comprehensive set of security headers in your Nginx configuration, which is fantastic! These headers are critical for protecting your website and its users from various web vulnerabilities. They act as instructions to modern web browsers, telling them how to behave when interacting with your site.
Let's break down each one:
1. add_header X-XSS-Protection "1; mode=block" always;
- Explanation: This header enables the XSS (Cross-Site Scripting) filter built into many modern web browsers.
1
: Enables the filter.mode=block
: If an XSS attack is detected, the browser will prevent rendering of the entire page instead of attempting to sanitize it. This is generally safer.
- Security Benefit: Helps mitigate reflected XSS attacks by instructing the browser to activate its built-in XSS protection.
- Performance Impact: Negligible. The browser handles the XSS filtering, not Nginx.
- Suggestion: Keep this header. It provides a useful layer of defense, especially for older browsers or as a fallback.
2. add_header X-Content-Type-Options "nosniff" always;
- Explanation: This header prevents browsers from "sniffing" the MIME type of a response. Without it, browsers might try to guess the content type of a file (e.g., interpret a
.txt
file as an executable script) if theContent-Type
header is missing or generic. - Security Benefit: Prevents MIME-sniffing attacks. This is crucial for preventing browsers from executing malicious code disguised as other file types (like an image). For example, it stops a browser from trying to execute a
.txt
file as JavaScript. - Performance Impact: Negligible.
- Suggestion: Keep this header. It's a fundamental security hardening measure.
3. add_header Referrer-Policy "no-referrer-when-downgrade" always;
- Explanation: This header controls how much referrer information (the URL of the previous page) is sent to other sites when a user clicks a link from your site.
no-referrer-when-downgrade
: The browser sends the full referrer URL for requests within your site or to other HTTPS sites. However, no referrer is sent when navigating from an HTTPS site (your site) to an insecure HTTP site.
- Security/Privacy Benefit: Balances privacy and functionality. It protects user privacy by not leaking sensitive URLs to insecure destinations while still providing useful referrer information for secure analytics and tracking.
- Performance Impact: Negligible.
- Suggestion: This is a good, balanced policy. Many prefer more restrictive policies like
same-origin
orno-referrer
for maximum privacy, butno-referrer-when-downgrade
is a widely adopted secure default.
4. add_header Content-Security-Policy "default-src 'self' http: https: ws: wss: data: blob: 'unsafe-inline'; frame-ancestors 'self';" always;
- Explanation: This is one of the most powerful and complex security headers. Content Security Policy (CSP) helps prevent various types of injection attacks, including XSS. It works by whitelisting the sources of content (scripts, stylesheets, images, fonts, etc.) that the browser is allowed to load and execute for a given page.
default-src 'self' http: https: ws: wss: data: blob: 'unsafe-inline';
: This is a very broad default policy.'self'
: Allows content only from your own domain.http: https: ws: wss: data: blob:
: These allow content over various protocols, including WebSocket connections (ws:
andwss:
), and inline data URIs (data:
,blob:
).'unsafe-inline'
: This is a significant security exception. It allows inline JavaScript and CSS. While it makes CSP easier to implement, it largely negates one of CSP's primary XSS protections.
frame-ancestors 'self';
: Restricts which domains can embed your content in an<iframe>
or<frame>
.'self'
means only pages from your own domain can frame your content, preventing clickjacking.
- Security Benefit: When correctly implemented (without
unsafe-inline
), CSP drastically reduces the attack surface for XSS, data injection, and clickjacking attacks. - Performance Impact: Negligible for Nginx. It's an instruction to the browser.
- Suggestions:
- Crucial Improvement: The most important suggestion here is to remove
'unsafe-inline'
from yourContent-Security-Policy
and instead use SHA-256 hashes or nonces for inline scripts/styles.'unsafe-inline'
effectively renders a large part of CSP's XSS protection useless. This often requires changes to your application to generate these hashes or nonces. - Be Specific: Instead of a broad
default-src
, use more specific directives likescript-src
,style-src
,img-src
,font-src
,connect-src
, etc., to tightly control each type of resource. - Monitor First: For complex applications, start with
Content-Security-Policy-Report-Only
(which only reports violations to a specified URI, rather than blocking them) to identify issues before enforcing a strict policy. - Example (more secure, but requires app changes):
add_header Content-Security-Policy "default-src 'self'; script-src 'self' https://cdn.example.com; style-src 'self' 'sha256-YOURHASHHERE'; img-src 'self' data:; connect-src 'self' ws: wss:; frame-ancestors 'self';" always;
- Crucial Improvement: The most important suggestion here is to remove
5. add_header Permissions-Policy "interest-cohort=()" always;
- Explanation: This header (formerly
Feature-Policy
) allows you to explicitly enable or disable various browser features and APIs for your own origin and for third-party content embedded on your site.interest-cohort=()
: Specifically disables the "Federated Learning of Cohorts" (FLoC) API. FLoC was Google's proposed privacy-preserving alternative to third-party cookies for interest-based advertising, but it has faced significant privacy concerns.
- Security/Privacy Benefit: Gives you control over browser features that might have privacy implications or could be exploited. Disabling
interest-cohort
explicitly opts your site out of FLoC tracking. - Performance Impact: Negligible.
- Suggestion: This is a good and relevant privacy-focused setting for current web standards. Keep it.
6. add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
- Explanation: This is the HSTS (HTTP Strict Transport Security) header, a critical security measure.
max-age=31536000
: Instructs the browser to only connect to your domain over HTTPS for the next 31,536,000 seconds (1 year). Even if a user tries to accesshttp://yourdomain.com
, the browser will automatically rewrite it tohttps://yourdomain.com
without even sending a request to the insecure HTTP port.includeSubDomains
: Applies the HSTS policy to all subdomains (e.g.,blog.linuxmalaysia.com
,shop.linuxmalaysia.com
).preload
: This flag is a signal that your domain is eligible for inclusion in browser's HSTS preload lists. Submitting your domain to the [HSTS Preload List](https://hstspreload.org/) ensures that browsers never try to connect to your site over HTTP, even on the very first visit.
- Security Benefit:
- Prevents SSL Stripping: Protects against "SSL stripping" attacks where an attacker downgrades an HTTPS connection to HTTP.
- Eliminates Mixed Content Issues: Reduces the likelihood of mixed content warnings by forcing HTTPS.
- Protects First Visit: The
preload
flag is key for the "trust on first use" problem, where the very first connection to a site could be vulnerable.
- Performance Impact:
- Minor initial overhead: The browser might need to parse this header once.
- Faster Subsequent Connections: By forcing HTTPS and removing the need for 301 redirects from HTTP to HTTPS, it actually speeds up subsequent connections.
- Important Considerations:
- HTTPS Must Be Rock Solid: Do not enable HSTS (especially
preload
) unless your entire domain, including all subdomains, is exclusively and permanently served over HTTPS. If any part of your site ever serves over HTTP, users might be locked out. - Difficult to Revert: Once your domain is on the HSTS preload list, it's very difficult to remove.
- HTTPS Must Be Rock Solid: Do not enable HSTS (especially
Overall Security and Performance of Headers:
Your security headers are a strong foundation! They demonstrate a clear commitment to user security.
- The
X-XSS-Protection
,X-Content-Type-Options
, andReferrer-Policy
are good, standard security measures. Permissions-Policy
is a modern privacy enhancement.- HSTS (
Strict-Transport-Security
) is excellent and highly recommended. - Content Security Policy (
Content-Security-Policy
) is the most powerful but also the most nuanced. Theunsafe-inline
directive is a significant weakness in your current CSP that you should prioritize addressing for maximum protection.
Applying these headers doesn't add much, if any, overhead to Nginx's processing. Their benefit lies in guiding browser behavior for a more secure user experience, which indirectly contributes to performance by preventing security incidents that could otherwise degrade service.
Do you have plans to tighten up your Content Security Policy, or are there any other security aspects you're considering for your Nginx setup in Cyberjaya?
Nginx Proxy Timeout Settings Explained
You're looking at the proxy timeout directives, which are critical for controlling how long Nginx waits for your backend application to respond. These settings directly impact the responsiveness and reliability of your service, especially when your backend is under load or experiencing issues.
All of these timeouts are set to 60s
(60 seconds), which is a common value for general web applications. Let's break down what each one means:
1. proxy_connect_timeout 60s;
- Explanation: This sets the maximum time Nginx will wait to establish a connection with your proxied backend server (
http://127.0.0.1:3000
). This includes the time needed for DNS resolution (if using a hostname), establishing the TCP handshake, and performing the SSL/TLS handshake (if your backend uses HTTPS). - Performance Impact:
- Responsiveness: If your backend server is slow to respond to new connection requests (e.g., due to high load, network issues, or a crash), Nginx will wait up to 60 seconds. If the connection isn't established within this time, Nginx will return a
502 Bad Gateway
error to the client. - Backend Health: A higher timeout gives a struggling backend more time to recover and accept new connections. A lower timeout makes Nginx fail faster, potentially preventing requests from piling up on a dead backend.
- Responsiveness: If your backend server is slow to respond to new connection requests (e.g., due to high load, network issues, or a crash), Nginx will wait up to 60 seconds. If the connection isn't established within this time, Nginx will return a
- Suggestions:
60s
is a generous timeout. For most well-behaved local backends, connection establishment should be near-instantaneous.- If your backend is highly performant and stable, you could consider lowering this to
5s
or10s
to make Nginx fail faster when the backend is truly unreachable, giving immediate feedback to the client or allowing other mechanisms (like retries) to kick in sooner. - If your backend starts slowly or occasionally takes time to come online (less common for a Node.js app on
127.0.0.1
), a higher value like60s
might be necessary.
2. proxy_send_timeout 60s;
- Explanation: This sets the maximum time Nginx will wait for your backend server to send a response after it has processed a request. Specifically, it's the timeout for sending a request to the proxied server. It applies between two successive write operations, not for the entire response. If the backend doesn't send anything for 60 seconds (no data, no headers), Nginx will close the connection.
- Performance Impact:
- Backend Stuck: Protects Nginx from a backend that accepts a connection but then gets "stuck" and doesn't write any data back to Nginx.
- Resource Management: Prevents Nginx from holding open connections indefinitely to a non-responsive backend, freeing up Nginx's resources.
- Suggestions:
60s
is a standard and generally safe value.- For applications that involve very long-running writes from the backend (e.g., large file uploads from the backend to Nginx, or streaming responses), you might need to increase this. However, for typical web requests,
60s
is usually sufficient.
3. proxy_read_timeout 60s;
- Explanation: This sets the maximum time Nginx will wait for your backend server to send data in response to a request. This applies between two successive read operations. If Nginx doesn't receive any data from the backend for 60 seconds, it will close the connection. This is typically the most important timeout for user experience.
- Performance Impact:
- User Experience: Directly impacts how long a user waits for a response. If your backend takes longer than 60 seconds to start sending the response (or send another chunk of data), the user will see a timeout error.
- Backend Processing Time: If your backend application has computationally intensive tasks or database queries that might exceed 60 seconds to complete, you'll need to increase this timeout.
- Resource Management: Prevents Nginx from tying up resources waiting for a backend that is too slow or unresponsive.
- Suggestions:
60s
is a common default, suitable for most web applications.- Adjust based on application needs: If you have long-running API calls, complex reports, or file generation processes in your backend that might genuinely take more than 60 seconds, you must increase this timeout (e.g.,
120s
,300s
, or even more). - For interactive or fast-response APIs, you could consider lowering it (e.g.,
30s
) to ensure quicker failure feedback.
Overall Impact on Nginx Performance (CPU and Memory)
- CPU/Memory: These timeouts don't directly consume CPU or memory during normal operation. Their impact comes when timeouts occur. If a timeout happens, Nginx might use a small amount of CPU to log the error and terminate the connection. Having appropriate timeouts prevents Nginx from holding open connections indefinitely to a problematic backend, which could otherwise tie up Nginx's worker processes and consume memory unnecessarily.
- Reliability: By setting these timeouts, you define the acceptable window for your backend to perform. If it exceeds these, Nginx intervenes, preventing users from waiting indefinitely and allowing Nginx to free up resources.
Your current timeout settings are a sensible starting point for many web applications. The key is to monitor your Nginx error logs for 502 Bad Gateway
errors or "upstream timed out" messages, as these would indicate that your backend is hitting these limits, and you might need to adjust them based on your application's specific behavior.
Nginx Logging Configuration Explained
You've provided your Nginx logging configuration, which is essential for monitoring the health, activity, and potential issues on your server. These settings tell Nginx where to record information and how verbose those logs should be.
Let's break down each line:
1. access_log /var/log/nginx/access.log combined buffer=512k flush=1m;
This directive configures the access log, which records every request Nginx handles.
/var/log/nginx/access.log
: This is the path to the file where Nginx will write access log entries. It's standard practice to keep Nginx logs in the/var/log/nginx/
directory.- Performance Impact: Logging to disk involves disk I/O. For very high-traffic sites, excessive logging (or logging to slow disks) can become a bottleneck. However, the buffering parameters you've set help mitigate this.
- Suggestion: Ensure the
www-data
user has write permissions to/var/log/nginx/
.
combined
: This specifies the log format to be used. Thecombined
format is a standard Apache-like format that includes common information like:- Remote IP address
- Request time
- HTTP method and URI
- HTTP status code
- Response body size
- Referer header
- User-Agent header
- Performance Impact: The chosen format slightly affects the amount of data written, but
combined
is a good balance between detail and file size. - Suggestion:
combined
is excellent for most purposes. If you ever need more detailed information (e.g., specific headers, upstream response times), you can define a customlog_format
.
buffer=512k
: This enables buffering of log entries in memory. Nginx will collect log entries up to512 kilobytes
in size before writing them to disk.- Performance Impact (CPU & Disk I/O): This is a significant optimization for busy servers. Instead of writing each log entry individually (which causes many small disk I/O operations and context switches), Nginx writes larger chunks less frequently. This reduces disk I/O, saves CPU cycles, and improves overall throughput.
- Memory Impact: Directly consumes
512KB
of RAM for the buffer. This is a very small and acceptable overhead for the performance gain. - Suggestion:
512k
is a good size. For extremely high-traffic sites, you might consider increasing this to1m
or2m
, but it's often not necessary.
flush=1m
: This directive works withbuffer
. It sets a maximum time limit for how long buffered log entries can remain in memory before being written to disk, even if the buffer isn't full. Here, it means that even if the512k
buffer isn't filled, Nginx will write its contents to disk every1 minute
.- Performance Impact: Ensures that log data isn't held indefinitely in memory, which is important for real-time monitoring and analysis, as well as data persistence in case of an unexpected crash.
- Suggestion:
1m
is a standard and reasonable flush interval.
2. error_log /var/log/nginx/error.log warn;
This directive configures the error log, which records messages about Nginx's own operations, warnings, and errors.
/var/log/nginx/error.log
: This is the path to the file where Nginx will write error log entries.- Performance Impact: Less frequent writing than access logs, as it only records problems. The performance impact is minimal.
- Suggestion: As with access logs, ensure correct write permissions.
warn
: This sets the minimum severity level of messages that will be written to the error log. Nginx logs messages at different levels:debug
,info
,notice
,warn
,error
,crit
,alert
, andemerg
(from most verbose to least verbose).- Performance Impact: A lower (more verbose) log level (e.g.,
info
ordebug
) will write many more messages, increasing disk I/O and potentially consuming more CPU. A higher (less verbose) level (e.g.,error
orcrit
) will log fewer messages. warn
level: Means Nginx will log messages withwarn
severity or higher (i.e.,warn
,error
,crit
,alert
,emerg
). This is a good balance:- It captures important warnings (e.g.,
keys_zone
full, deprecated directives, OCSP stapling issues) that you should be aware of. - It avoids flooding the log with
info
ordebug
messages, which are usually only needed during active troubleshooting.
- It captures important warnings (e.g.,
- Suggestion:
warn
is an excellent choice for a production environment. For active debugging, you might temporarily switch toinfo
or evendebug
(if Nginx was compiled with debugging enabled), but always revert towarn
or higher for normal operation.
- Performance Impact: A lower (more verbose) log level (e.g.,
Overall Impact on Nginx Performance (CPU and Memory)
- CPU: Logging consumes some CPU for formatting log entries and performing disk I/O. The
buffer
setting for access logs significantly reduces this overhead. - Memory: A small amount of memory is used for the
access_log
buffer (512k
). - Disk I/O: Both logs write to disk. Efficient logging practices (like buffering) minimize the impact on disk I/O.
- Visibility & Debugging: While not a direct performance gain in terms of request processing speed, well-configured logging is paramount for identifying performance bottlenecks, security incidents, and operational issues. Without proper logs, troubleshooting becomes significantly harder, leading to longer downtimes or unaddressed problems that do affect performance.
Your logging configuration is very solid, balancing verbosity with performance by utilizing buffering for access logs and a sensible warning level for error logs.
HTTP to HTTPS Redirect Configuration
This server
block is solely dedicated to handling HTTP requests and redirecting them to your secure HTTPS site. This is a crucial security and SEO best practice.
Let's break down each part:
-
listen 80 reuseport;
- Explanation: This tells Nginx to listen for incoming connections on port 80 (the standard port for unencrypted HTTP traffic) for IPv4 addresses. The
reuseport
option (available in Nginx 1.9.1+ on Linux) allows multiple worker processes to listen on the same port, which can improve performance by distributing incoming connections more evenly across workers. - Performance Impact: Listening on port 80 is necessary to capture all HTTP requests.
reuseport
can offer minor performance benefits on high-concurrency systems by reducing lock contention when accepting new connections.
- Explanation: This tells Nginx to listen for incoming connections on port 80 (the standard port for unencrypted HTTP traffic) for IPv4 addresses. The
-
listen [::]:80 reuseport;
- Explanation: This is similar to the above, but it tells Nginx to listen on port 80 for IPv6 addresses. This ensures that users connecting via IPv6 are also correctly redirected.
- Performance Impact: Same as the IPv4
listen
directive.
-
server_name linuxmalaysia.com;
- Explanation: This specifies that this
server
block should handle requests for the domainlinuxmalaysia.com
. If you have other domains or subdomains, you'd need separateserver_name
entries or additionalserver
blocks for them. - Performance Impact: Nginx efficiently matches
server_name
directives to direct traffic to the correct block.
- Explanation: This specifies that this
-
access_log /var/log/nginx/access.log combined buffer=512k flush=1m;
- Explanation: This configures access logging for this specific HTTP redirect block. It uses the
combined
format, buffers logs in memory (up to 512KB), and flushes them to disk every 1 minute. This is the same logging configuration as your main HTTPS block. - Performance Impact: Logging has a small overhead, but the buffering helps minimize its impact on disk I/O and CPU, even for redirect-only requests. It's useful to log redirects to ensure they're happening as expected.
- Explanation: This configures access logging for this specific HTTP redirect block. It uses the
-
error_log /var/log/nginx/error.log warn;
- Explanation: This configures error logging for this block, setting the minimum severity level to
warn
. - Performance Impact: Minimal, as errors are less frequent. It helps in diagnosing any issues with the redirection process.
- Explanation: This configures error logging for this block, setting the minimum severity level to
-
return 301 https://linuxmalaysia.com$request_uri;
- Explanation: This is the core of the redirection.
return 301
: Nginx will send an HTTP301 Moved Permanently
status code to the client. This is crucial for SEO, as it tells search engines that the content has permanently moved to the HTTPS version, transferring any SEO "link juice" to the new URL.https://linuxmalaysia.com
: This is the target protocol and domain.$request_uri
: This Nginx variable preserves the original path and query string from the incoming HTTP request. So, if a user typeshttp://linuxmalaysia.com/about?lang=en
, they will be redirected tohttps://linuxmalaysia.com/about?lang=en
.
- Performance Impact: This is an incredibly efficient way to handle redirects in Nginx. Nginx doesn't need to process the request further or hit your backend application; it simply sends the redirect header directly. This minimizes CPU and memory usage for HTTP requests.
- Explanation: This is the core of the redirection.
Overall Performance and Importance
This entire server
block is extremely important for:
- Security: Forcing all traffic to HTTPS is fundamental for securing user data and ensuring privacy.
- SEO (Search Engine Optimization): Using a
301
redirect ensures that search engines correctly update their indexes and your site doesn't lose ranking due to duplicate content (HTTP vs. HTTPS). - User Experience: While it adds a single extra HTTP round-trip for the initial redirect, it ensures users always land on the secure version of your site. Modern browsers (especially with HSTS preloading) often automatically upgrade HTTP requests to HTTPS, making this redirect transparent after the first visit.
- Efficiency: Nginx handles this redirect very efficiently, serving the redirect directly without involving your backend application.
This is a standard and highly recommended configuration for any website using HTTPS. You've implemented it correctly and efficiently.
Nginx Proxy SSL Server Name Indication (SNI)
You're asking about the proxy_ssl_server_name
directive. This setting is crucial when Nginx is proxying HTTPS requests to a backend server that hosts multiple SSL certificates on the same IP address.
Here's a breakdown:
What is SNI (Server Name Indication)?
Traditionally, for a server to host multiple secure websites (each with its own SSL certificate) on a single IP address, it would need a separate IP address for each. This is because the SSL handshake happens before the HTTP Host
header (which indicates the desired website) is sent. So, the server wouldn't know which certificate to present.
Server Name Indication (SNI) is an extension to the TLS protocol that solves this problem. With SNI, the client (e.g., a web browser) includes the hostname it's trying to connect to within the initial TLS handshake. This allows the server to present the correct SSL certificate, even if it's hosting many websites on the same IP address.
proxy_ssl_server_name on;
- Explanation: When
proxy_ssl_server_name
is set toon
, Nginx will pass the hostname from the client's original request (theHost
header Nginx received from the client) to your backend server during the SSL/TLS handshake. - How it works:
- A client connects to Nginx over HTTPS (e.g.,
https://linuxmalaysia.com
). - Nginx receives the request, including the
Host
header (linuxmalaysia.com
). - Nginx acts as a client to your backend server (
http://127.0.0.1:3000
). - If your backend also uses HTTPS (e.g.,
https://127.0.0.1:3000
), Nginx will include the original hostname (linuxmalaysia.com
) in its TLS handshake with the backend. - This allows your backend server to select and present the correct SSL certificate for
linuxmalaysia.com
(if it hosts multiple SSL-secured sites) to Nginx.
- A client connects to Nginx over HTTPS (e.g.,
- When it's important: This setting is essential if:
- Your Nginx instance is proxying to an HTTPS backend (meaning
proxy_pass
is tohttps://...
). - And that HTTPS backend hosts multiple domains/certificates on the same IP address. Without
proxy_ssl_server_name on;
, the backend might present the wrong certificate, leading to SSL errors between Nginx and the backend.
- Your Nginx instance is proxying to an HTTPS backend (meaning
Performance Impact
- Negligible on CPU/Memory: This setting has a minimal to negligible impact on Nginx's CPU or memory usage. It's primarily about ensuring the correct SSL handshake happens between Nginx and the backend.
- Crucial for Correctness: Its main "performance" benefit is that it enables your SSL-secured backend to function correctly in a multi-domain setup. Without it, you'd encounter SSL handshake failures or certificate mismatches between Nginx and your backend, leading to client errors and service outages.
Suggestions
- Keep it
on
if your backend uses HTTPS and hosts multiple domains: If yourproxy_pass
URL ishttps://127.0.0.1:3000
(instead ofhttp://127.0.0.1:3000
as in your current config) AND your backend application serves different domains over HTTPS from a single IP, thenproxy_ssl_server_name on;
is absolutely necessary. - It's currently redundant in your provided config: In your current configuration,
proxy_pass
is set tohttp://127.0.0.1:3000;
. This means Nginx is connecting to your backend using plain HTTP, not HTTPS. In this scenario,proxy_ssl_server_name on;
has no effect because there's no SSL handshake happening between Nginx and the backend.
Conclusion: While proxy_ssl_server_name on;
is a best practice for Nginx when proxying to HTTPS backends, it's currently a no-op given your proxy_pass http://127.0.0.1:3000;
directive. If you ever switch your backend to serve over HTTPS, this line will become highly relevant and important.
Nginx Security and .well-known
File Handling
You're configuring some important aspects of how Nginx handles specific files and directories, particularly those starting with a dot (.
) and the security.txt
file. These settings are crucial for both security and compliance with modern web standards.
Let's break down each of these location
blocks:
1. location ~ /\.(?!well-known) { deny all; }
- Explanation: This
location
block uses a regular expression to match requests for files or directories that start with a dot (.
) but are NOT within the.well-known
directory.~
: Indicates a regular expression match (case-sensitive)./\.
: Matches a literal dot at the beginning of a path segment (like.htaccess
,.env
,.git
).(?!well-known)
: This is a negative lookahead assertion. It means "match a dot, but only if it's NOT followed by 'well-known'".deny all;
: If a request matches this pattern, Nginx will immediately deny access, returning a403 Forbidden
error.
- Security Benefit: This is a critical security measure. Many sensitive files used by applications or version control systems (like
.env
for environment variables,.git
for Git repositories,.htaccess
for Apache configurations) start with a dot. Serving these files publicly could expose sensitive information, leading to severe security vulnerabilities. This directive ensures they are never served by Nginx. - Performance Impact: Negligible. It's a quick check and deny, which is very efficient.
- Suggestion: Keep this as is. It's a fundamental security best practice.
2. location /security.txt { return 301 /.well-known/security.txt; }
- Explanation: This
location
block handles requests for/security.txt
. It issues a permanent redirect (301 Moved Permanently
) to/.well-known/security.txt
. - Security Benefit: The
security.txt
file is a proposed standard for website security, allowing security researchers to easily find contact information for reporting vulnerabilities. The official standard dictates it should be placed under the/.well-known/
directory. This redirect ensures that if someone (human or automated scanner) looks for the file at the old or common root location, they are guided to the correct, standardized location. - Performance Impact: Minor. It's a single HTTP redirect. The
301
status code tells browsers and search engines to cache the redirect, so subsequent requests go directly to the new location. - Suggestion: Keep this redirect. It helps with compliance and discoverability for security researchers.
3. location = /.well-known/security.txt { alias ~/security.txt; }
- Explanation: This
location
block specifically handles requests for/.well-known/security.txt
.=
: Denotes an exact match. This means this block will only process requests that precisely match/.well-known/security.txt
.alias ~/security.txt;
: This is an important part.alias
: Specifies a different base path for the file than theroot
directive of theserver
block.~/security.txt
: The tilde~
symbol usually refers to the user's home directory. If Nginx is running aswww-data
,~
would typically resolve to/var/www/
. This implies yoursecurity.txt
file is expected to be located at/var/www/security.txt
(or/home/www-data/security.txt
if that's the user's home).
- Security Benefit: Correctly serves the
security.txt
file from a designated location, fulfilling the proposed standard for vulnerability reporting. - Performance Impact: Negligible. Serving a small static file is very efficient for Nginx.
- Important Consideration / Suggestion:
- File Location: You need to ensure that the
security.txt
file actually exists at the path specified byalias ~/security.txt
. Based on your earlierroot /var/www/linuxmalaysia.com/public;
setting, a more common and explicit path for this would bealias /var/www/linuxmalaysia.com/security.txt;
or evenalias /etc/nginx/security.txt;
if you prefer to keep it separate from your website's public directory. - User Permissions: The Nginx user (
www-data
) must have read permissions for thesecurity.txt
file at thealias
path.
- File Location: You need to ensure that the
Overall Summary of these Directives:
These location
blocks demonstrate good practices for managing specific file access and adhering to web standards:
- The
deny all
for dotfiles is a crucial security hardened default. - The
security.txt
redirects and serving ensure you comply with a valuable security and transparency standard.
Your configuration for these elements is generally solid. The main point to double-check is the exact path of your security.txt
file to ensure it aligns with the alias
directive's interpretation of ~
.
Is there anything else you'd like to understand about your Nginx setup, or any other parts of the configuration you'd like to review?
Nginx Request Method Restriction
You're using an if
directive to restrict the HTTP methods that Nginx will allow for requests. This is a security measure that can help protect your backend application from unexpected or potentially malicious requests using methods your application isn't designed to handle.
Let's break down this configuration:
-
if ($request_method !~ ^(GET|POST|PUT|HEAD|CONNECT)$) { ... }
if
directive: This is a conditional statement in Nginx. While generally discouraged for complex logic (due to some known issues and performance characteristics with complexif
blocks), for simple checks like this, it's often used.$request_method
: This is a built-in Nginx variable that holds the HTTP method of the current request (e.g.,GET
,POST
,DELETE
,OPTIONS
).!~
: This is the "does not match" operator for regular expressions (case-sensitive).^(GET|POST|PUT|HEAD|CONNECT)$
: This is the regular expression pattern.^
: Matches the beginning of the string.$
: Matches the end of the string.(GET|POST|PUT|HEAD|CONNECT)
: This is a group that matches any of the specified HTTP methods.GET
: Used to retrieve data.POST
: Used to submit data to be processed.PUT
: Used to create or replace a resource.HEAD
: Similar to GET, but requests only the headers, not the body.CONNECT
: Used to establish a tunnel to the server, primarily for proxies.
- In summary: The
if
condition evaluates totrue
if the$request_method
is not one ofGET
,POST
,PUT
,HEAD
, orCONNECT
.
-
return '405';
- Explanation: If the
if
condition is true (i.e., the request method is not one of the allowed ones), Nginx will immediately return an HTTP405 Method Not Allowed
status code to the client. This tells the client that the method used is not supported for the requested resource.
- Explanation: If the
Security Benefit
- Method Filtering: This helps ensure that your backend application only receives requests using the HTTP methods it's designed to process.
- Reduced Attack Surface: By explicitly denying unexpected methods, you can reduce the attack surface. For example, if your application doesn't implement
DELETE
orOPTIONS
(which it likely should for REST APIs, but this is a generic setup), blocking them at the Nginx level can prevent potential vulnerabilities if these methods were somehow mishandled by your backend. - Compliance: Can help in scenarios where strict adherence to allowed methods is required.
Performance Impact
- Minimal CPU/Memory: The impact on Nginx's CPU and memory is very minimal. Regular expression matching for a short string is a highly optimized operation. If a method is denied, Nginx returns the error immediately, consuming very few resources for that request.
- Efficiency: For disallowed methods, Nginx efficiently terminates the request at the edge, preventing it from ever reaching your backend application. This saves CPU and resources on your backend that would otherwise be spent processing and rejecting an invalid request.
Suggestions
- Consider your application's needs: Before implementing method restrictions, ensure that your backend application genuinely does not use any other HTTP methods.
- For a typical RESTful API, you'd usually also allow
DELETE
andPATCH
. OPTIONS
is commonly used for CORS (Cross-Origin Resource Sharing) preflight requests. If you have a frontend application on a different domain interacting with your backend, denyingOPTIONS
will break CORS.
- For a typical RESTful API, you'd usually also allow
- Placement: This
if
block is typically placed within aserver
block or a specificlocation
block. Placing it in thehttp
block (which seems to be the case here, given the context of your previous snippets) applies it globally to allserver
blocks unless overridden. This is fine for a blanket restriction. - Nginx
if
directive caution: While this specific use case is generally considered acceptable forif
, it's worth noting that theif
directive can sometimes lead to unexpected behavior when combined with other directives, especially in more complex scenarios. For method restriction specifically, it's usually safe.
In summary, this if
block is a simple yet effective security measure to restrict HTTP methods, contributing to a more robust and secure Nginx setup. Just ensure the allowed methods align with your application's actual requirements.
Nginx Configuration for favicon.ico
and robots.txt
These two location
blocks are dedicated to handling requests for favicon.ico
and robots.txt
. While seemingly minor, they help optimize your Nginx logs and prevent unnecessary logging noise, which can be beneficial for performance in very high-traffic scenarios.
Let's look at each:
1. location = /favicon.ico { log_not_found off; }
-
Explanation: This block specifically targets requests for
/favicon.ico
.location = /favicon.ico
: The=
sign ensures an exact match for this URI. Requests forfavicon.ico
(which is the small icon displayed in browser tabs) are very common.log_not_found off;
: This is the key part. It tells Nginx not to log 404 "file not found" errors to theerror_log
iffavicon.ico
isn't found.
-
Performance Impact:
- Reduced Log Noise: Favicons are often requested automatically by browsers, and if the file doesn't exist (or isn't found at that exact path), it would generate a
404
error entry in yourerror_log
. Turninglog_not_found off
keeps your error logs cleaner and more focused on actual issues. - Minimal CPU/Disk I/O: For very high-traffic sites, preventing thousands of
404
error log entries can save a tiny amount of CPU and disk I/O, as Nginx doesn't have to write these messages. This is more about efficiency and clean logs than a major performance boost.
- Reduced Log Noise: Favicons are often requested automatically by browsers, and if the file doesn't exist (or isn't found at that exact path), it would generate a
-
Suggestion: Keep this setting. It's a standard and good practice for managing Nginx logs.
2. location = /robots.txt { log_not_found off; }
-
Explanation: This block is identical in purpose to the
favicon.ico
one, but it applies to/robots.txt
.location = /robots.txt
: Ensures an exact match for therobots.txt
file, which search engine crawlers (like Googlebot) request to understand your site's crawling rules.log_not_found off;
: Prevents404
errors forrobots.txt
from being logged if the file isn't found.
-
Performance Impact:
- Reduced Log Noise: Similar to
favicon.ico
, ifrobots.txt
isn't present or found by Nginx, it would generate404
entries. This directive keeps those out of your error logs. - Minimal CPU/Disk I/O: Again, this contributes to marginal savings in CPU and disk I/O by avoiding unnecessary log writes.
- Reduced Log Noise: Similar to
-
Suggestion: Keep this setting. It's another standard and good practice for log management.
Overall Summary
These directives don't directly enhance the speed of content delivery, but they are beneficial for the operational efficiency and clarity of your Nginx server. By explicitly turning off 404
logging for these commonly requested (and sometimes missing) files, you keep your error logs focused on more significant issues, making it easier to monitor and troubleshoot your server. This is especially useful for managing a web server like yours, which handles traffic in Cyberjaya, Selangor, Malaysia, and globally.
That's a very common if
block you've got there! While it serves a good purpose in restricting HTTP methods, the general consensus in the Nginx community is to avoid if
statements when possible due to potential unexpected behavior in certain complex scenarios.
However, for simple method checks like this, it's often deemed acceptable. If you're running a basic web server with a standard application (like a blog or a simple API), your current setup is likely fine and provides good security benefits by explicitly allowing only the methods your application expects.
Here are a few suggestions based on your current configuration and common Nginx practices:
1. Keep it as is (if your application strictly uses these methods)
If your application truly only relies on GET
, POST
, PUT
, HEAD
, and CONNECT
methods, then your current if
statement effectively limits unnecessary requests to your backend, providing a basic security layer.
- Pros: Simple, readable, and immediately understood. It effectively filters unwanted methods at the Nginx edge.
- Cons: Uses an
if
statement, which purists generally avoid, though its impact here is minimal. - Use Case: Ideal for applications that definitely don't use methods like
DELETE
,PATCH
, orOPTIONS
(e.g., a static site served through Nginx, or an API that uses only the listed methods).
2. Refine the Allowed Methods (if your application needs more)
Consider if your application requires other standard HTTP methods. For example, if you're building a RESTful API, you'll very likely need DELETE
and PATCH
. Additionally, OPTIONS
is frequently used for CORS (Cross-Origin Resource Sharing) preflight requests. If you have a frontend JavaScript application hosted on a different domain from your API, it will send OPTIONS
requests, and blocking them will break your frontend's ability to communicate with the API.
Suggestion: Add any methods your application legitimately uses. For a typical API, a more comprehensive list might look like this:
---
# Suggested Method Restriction
if ($request_method !~ ^(GET|POST|PUT|DELETE|PATCH|HEAD|OPTIONS|CONNECT)$) {
return 405;
}
- Pros: Ensures your application functions correctly with all necessary HTTP verbs. Handles common CORS scenarios.
- Cons: Still uses an
if
statement. - Use Case: Recommended for modern web applications, especially those with APIs and separate frontends.
3. Remove the Restriction (if you're unsure or your backend handles it)
If you're unsure which methods your backend uses or if your application server (e.g., Node.js, Python, PHP framework) is already robustly handling method validation, you could simply remove this if
block.
- Pros: Simplifies your Nginx configuration. Defers method validation entirely to your application, which might be more appropriate if the application logic is complex.
- Cons: Less filtering at the Nginx edge; all method types will hit your backend, potentially exposing it to methods it doesn't handle.
- Use Case: When your application framework (like Express.js, Django REST Framework, Laravel) is explicitly designed to handle all HTTP methods and return appropriate
405
responses or specific logic for each, making Nginx's check redundant.
Which suggestion is best for you?
Given your setup with proxy_pass http://127.0.0.1:3000;
, it sounds like you're running a backend application (likely Node.js, since 3000 is a common port).
- If you're running a simple content-serving application or a blog without complex interactive features/APIs, then keeping your current list of methods is probably sufficient.
- However, if your
linuxmalaysia.com
site includes APIs, user interactions, or forms that might update/delete data, or if you have a separate frontend that makes AJAX requests, then I'd strongly suggest you refine the allowed methods to includeOPTIONS
,DELETE
, andPATCH
(if your API uses them). This will prevent unexpected405
errors and ensure full functionality.
Before making any changes, always test thoroughly to ensure your application behaves as expected with the chosen method restrictions!
User ulimit (for Nginx user):
Even with fs.file-max set, the user running Nginx (often nginx or www-data) needs a high nofile limit in /etc/security/limits.conf or a file in /etc/security/limits.d/.
nginx soft nofile 655360
nginx hard nofile 655360
Let's break down the events
block in your Nginx configuration. This block is crucial because it defines how Nginx handles connections and influences its scalability and performance, particularly concerning concurrent users.
events { ... }
The events
block is a top-level configuration block in Nginx (alongside http
, mail
, stream
, etc.). It contains directives that set global parameters for connection processing.
1. worker_connections 65536;
-
Explanation: This directive specifies the maximum number of simultaneous connections that a single Nginx worker process can open.
- Since Nginx typically runs multiple worker processes (controlled by
worker_processes
in the main configuration block, often set toauto
or the number of CPU cores), the total maximum number of connections Nginx can handle concurrently isworker_connections * worker_processes
. - For example, if you have 4 worker processes and
worker_connections 65536;
, Nginx can theoretically handle$4 \times 65536 = 262144$ simultaneous connections.
- Since Nginx typically runs multiple worker processes (controlled by
-
Performance Impact (Scalability & Resource Usage):
-
High Concurrency: A high
worker_connections
value allows Nginx to handle a very large number of concurrent clients, which is essential for high-traffic websites. - Memory: Each connection consumes a small amount of memory. Setting this too high without sufficient RAM could lead to memory exhaustion.
- CPU: While Nginx is very efficient, handling a vast number of connections will consume CPU cycles for processing requests.
- File Descriptors: Each connection is a file descriptor. This setting must be lower than or equal to the operating system's per-process file descriptor limit.
-
High Concurrency: A high
-
Suggestions:
-
65536
is a very common and high value, indicating a server designed for high concurrency. - Practical Limit: While Nginx might be configured for 65,536 connections per worker, the actual practical limit is often determined by the server's CPU, memory, and network bandwidth.
- Monitoring: Monitor your server's resource usage (CPU, RAM, open file descriptors) under load to ensure it can comfortably handle this many connections. If you consistently hit the limit, consider scaling up your hardware or optimizing other parts of your Nginx/application stack.
-
2. worker_rlimit_nofile 655360;
- Explanation: This directive sets the maximum number of open file descriptors (the
RLIMIT_NOFILE
limit) for Nginx's worker processes.- A file descriptor is used for every connection, every file being served, every log file, and so on.
- The value
655360
(655,360) is ten times yourworker_connections
value.
- Performance Impact (Stability & Reliability):
- Prevents "Too Many Open Files" Errors: If Nginx runs out of file descriptors, it cannot accept new connections or open files, leading to service disruption and "Too many open files" errors in your logs.
- Must be High Enough: This value must be at least
worker_connections
. It's often recommended to set it higher (e.g., 1.5x to 2xworker_connections
for general use, or even 10x as you have for very busy servers) to account for other file descriptors used by Nginx (e.g., log files, cache files, internal pipes, upstream connections). - Operating System Limit: This Nginx setting cannot exceed the operating system's system-wide file descriptor limit (
fs.file-max
) or the per-user/per-processulimit -n
setting. You often need to adjust these OS limits first.
- Suggestions:
655360
is a very high and appropriate value for a server aiming for high concurrency.- Verify OS Limits: Before setting
worker_rlimit_nofile
this high, you must ensure your Linux system'sulimit -n
for the Nginx user andfs.file-max
kernel parameter are set to at least this value (or higher).- To check
ulimit -n
for the Nginx user (e.g.,www-data
):sudo su - www-data -c 'ulimit -n'
- To check system-wide
fs.file-max
:cat /proc/sys/fs/file-max
- To temporarily set
ulimit -n
for the current shell (e.g., for testing):ulimit -n 655360
- To make it permanent, you'd typically edit
/etc/security/limits.conf
(fornofile
for thewww-data
user) and/etc/sysctl.conf
(forfs.file-max
).
- To check
3. use epoll;
(Example, commented out in your snippet)
- Explanation: This directive specifies the connection processing method Nginx will use.
epoll
is the most efficient and scalable I/O event notification mechanism on Linux systems. It allows Nginx to efficiently monitor a large number of file descriptors for readiness events (e.g., a new connection, data arriving on an existing connection).- Other methods exist (
kqueue
for FreeBSD/macOS,select
,poll
), butepoll
is the default and preferred method on Linux due to its superior performance for high concurrency.
- Performance Impact (CPU & Scalability):
- Highly Efficient:
epoll
drastically reduces the CPU overhead associated with monitoring thousands of connections compared to older methods likeselect
orpoll
. It scales very well with the number of connections.
- Highly Efficient:
- Suggestions:
- Explicitly include it: While Nginx often defaults to the best method for the detected OS, it's good practice to explicitly include
use epoll;
in yourevents
block if you're on Linux, as it clearly states your intent and ensures Nginx uses the most efficient method.
- Explicitly include it: While Nginx often defaults to the best method for the detected OS, it's good practice to explicitly include
Overall Impact on Nginx Performance (CPU and Memory)
- CPU:
worker_connections
and the chosenuse
method directly impact CPU. A higher number of connections means more work for the CPU, butepoll
minimizes the overhead of managing those connections. - Memory:
worker_connections
directly influences memory consumption as each connection requires a small amount of memory.worker_rlimit_nofile
ensures Nginx has enough capacity to use file descriptors but doesn't directly consume memory itself (it's a limit, not an allocation).
Your events
block configuration is very aggressive and suitable for a high-performance web server aiming to handle significant traffic, which aligns with serving linuxmalaysia.com
effectively. The high worker_connections
and worker_rlimit_nofile
values are excellent for scalability, provided your underlying operating system is also configured to support them.
Okay, this
map
directive is significantly more complex than the previous one, but it serves a very important purpose: correctly handling and appending to the standardizedForwarded
HTTP header in a multi-proxy environment.This
map
builds upon the$proxy_forwarded_elem
variable that we just discussed.The Problem: Multiple Proxies
Imagine this chain:
Client -> Proxy A (e.g., a CDN or Load Balancer) -> Nginx -> Backend Application
Forwarded
header (orX-Forwarded-For
), and forwards it to Nginx.Forwarded
header before passing it to the backend, without overwriting what Proxy A already added.This is precisely what this
map
aims to achieve for theForwarded
header (RFC 7239).Explaining the
map
BlockThis
map
directive defines a new variable called$proxy_add_forwarded
. Its value depends on the$http_forwarded
variable, which contains the incomingForwarded
header from the client (or the previous proxy).map $http_forwarded $proxy_add_forwarded { ... }
:$http_forwarded
: This is a built-in Nginx variable that captures the value of theForwarded
header sent by the client.$proxy_add_forwarded
: This is the new variable that Nginx will set. Its purpose is to be the finalForwarded
header value sent to the backend.The Long Regular Expression Line:
"~^...*$"
): This incredibly long regular expression attempts to validate if the incoming$http_forwarded
header is syntactically valid according to RFC 7239. It's designed to match the various components and formatting rules of theForwarded
header (which can includefor
,by
,proto
, andhost
parameters, separated by semicolons and commas)."$http_forwarded, $proxy_forwarded_elem"
): If the incomingForwarded
header is valid, then the$proxy_add_forwarded
variable will be set to:$http_forwarded
header value.,
.$proxy_forwarded_elem
variable (which, as we discussed, containsfor=<client-ip>
correctly formatted for IPv4/IPv6).map
entry effectively says: "If aForwarded
header already exists and it looks correct, then append our (Nginx's)for=
information to it." This maintains the proxy chain information.default "$proxy_forwarded_elem";
:default
): If the incoming$http_forwarded
header is not present, or if it is present but does not match the strict RFC 7239 validation regex (meaning it's syntactically incorrect or malformed), then thisdefault
rule applies."$proxy_forwarded_elem"
): In this case,$proxy_add_forwarded
will simply be set to the value of$proxy_forwarded_elem
.Forwarded
header coming in, or if it's messed up, then just start a new one with our (Nginx's)for=
information." This prevents propagating malformed headers and ensures your backend at least gets someForwarded
information from Nginx.How it's Used in Your Configuration
Finally, this
$proxy_add_forwarded
variable is used in yourproxy_set_header
directive:This is how the correctly constructed
Forwarded
header (either appended or newly created) is sent to your backend application (e.g.,http://127.0.0.1:3000
).Performance Impact
map
directive, themap
operation itself is highly optimized in Nginx. The main overhead comes from the regular expression matching. While the regex is complex, it's compiled efficiently by Nginx. For each request, this small amount of processing happens to determine the correctForwarded
header.Forwarded
header. This is invaluable for:In essence, this
map
provides a robust and RFC-compliant way for Nginx to participate in a multi-proxy environment, ensuring that the backend application receives accurate and completeForwarded
header information. This is a best practice for modern web infrastructure.