nginx microcaching config example

gistfile1.pl

# Set cache dir
proxy_cache_path /var/cache/nginx levels=1:2 
                 keys_zone=microcache:5m max_size=1000m;

# Virtualhost/server configuration
server {
    listen   80;
    server_name  yourhost.domain.com;

    # Define cached location (may not be whole site)
    location / {

        # Setup var defaults
        set $no_cache "";

        # If non GET/HEAD, don't cache & mark user as uncacheable for 1 second via cookie
        if ($request_method !~ ^(GET|HEAD)$) {
            set $no_cache "1";
        }

        # Drop no cache cookie if need be
        # (for some reason, add_header fails if included in prior if-block)
        if ($no_cache = "1") {
            add_header Set-Cookie "_mcnc=1; Max-Age=2; Path=/";            
            add_header X-Microcachable "0";
        }

        # Bypass cache if no-cache cookie is set
        if ($http_cookie ~* "_mcnc") {
            set $no_cache "1";
        }

        # Bypass cache if flag is set
        proxy_no_cache $no_cache;
        proxy_cache_bypass $no_cache;

        # Point nginx to the real app/web server
        proxy_pass http://appserver.domain.com;

        # Set cache zone
        proxy_cache microcache;

        # Set cache key to include identifying components
        proxy_cache_key $scheme$host$request_method$request_uri;

        # Only cache valid HTTP 200 responses for 1 second
        proxy_cache_valid 200 1s;

        # Serve from cache if currently refreshing
        proxy_cache_use_stale updating;

        # Send appropriate headers through
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        # Set files larger than 1M to stream rather than cache
        proxy_max_temp_file_size 1M;

        # Custom logging
        log_format custom '$remote_addr - $remote_user [$time_local]  '
                    '"$request" $status $body_bytes_sent '
                    '"$http_referer" "$http_user_agent" nocache:$no_cache';
        access_log  /var/log/nginx/microcache.log custom;

    }

}