Setup NGINX and ASP.NET Core on CentOS/RHEL for hosting sites on different ports and ASP.NET Core versions

Prerequisites

Update the installed packages.

yum update

Install the EPEL repository.

# CentOS/RHEL 6
rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm
# CentOS/RHEL 7
rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
yum install epel-release

Install the Linux Software Repository for Microsoft Products.

# CentOS/RHEL 6
sudo rpm -Uvh https://packages.microsoft.com/config/rhel/6/packages-microsoft-prod.rpm
# CentOS/RHEL 7
sudo rpm -Uvh https://packages.microsoft.com/config/rhel/7/packages-microsoft-prod.rpm

Install the REMI repository.

# CentOS/RHEL 6
rpm -Uvh https://rpms.remirepo.net/enterprise/remi-release-6.rpm
# CentOS/RHEL 7
rpm -Uvh https://rpms.remirepo.net/enterprise/remi-release-7.rpm

Check that the repositories are correctly installed.

yum repolist

Step 1 - Install NGINX

yum install nginx

Step 2 - Install the ASP.NET Core prerequisites

yum install krb5-libs libcurl libicu libunwind libuuid lttng-ust zlib

Step 3 - Setup the .NET SDK

Use the following commands on CentOS.

# ASP.NET Core 2.0
sudo yum install dotnet-sdk-2.1.202
# ASP.NET Core 2.1
sudo yum install dotnet-sdk-2.1

Use the following commands on RHEL.

# ASP.NET Core 2.0
yum install rh-dotnet20 -y
scl enable rh-dotnet20 bash
# ASP.NET Core 2.1
yum install rh-dotnet21 -y
scl enable rh-dotnet21 bash

Step 4 - Check the dotnet versions

dotnet --info

Step 5 - Configure the sites

Change directory to the default web directory.

# CentOS/RHEL 6
cd /usr/share/nginx/www
# CentOS/RHEL 7
cd /usr/share/nginx/html

Create the folders each site.

mkdir dotnet21-example dotnet20-example

Publish and deploy the ASP.NET Core 2.0 and 2.1 projects on their respective folders.

cd dotnet20-example
cd dotnet21-example

Step 6 - Setup the server blocks

Two server blocks will be created, one for each site, on ports 83 and 84 respectively.

cd /etc/nginx/conf.d
vim dotnet20-example.conf
vim dotnet21-example.conf

dotnet20-example.conf

server {
    listen 83;
    server_name _;
    root /usr/share/nginx/html/dotnet20-example;
    location / {
        proxy_cache_bypass $http_upgrade;
        proxy_http_version 1.1;
        proxy_pass http://localhost:5000;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection keep-alive;
        proxy_set_header Host $http_host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

dotnet21-example.conf

server {
    listen 84;
    server_name _;
    root /usr/share/nginx/html/dotnet21-example;
    location / {
        proxy_cache_bypass $http_upgrade;
        proxy_http_version 1.1;
        proxy_pass http://localhost:5001;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection keep-alive;
        proxy_set_header Host $http_host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

Step 7 - Check the NGINX configuration

nginx -t

Step 8 - Create the service definition files

Two services will be created, one for each site.

cd /etc/systemd/system
vim kestrel-dotnet20-example.conf
vim kestrel-dotnet21-example.conf

kestrel-dotnet20-example.service

[Unit]
Description=dotnet20-example

[Service]
WorkingDirectory=/usr/share/nginx/html/dotnet20-example
ExecStart=/usr/bin/dotnet /usr/share/nginx/html/dotnet20-example/dotnet20-example.dll
Restart=always
# Restart service after 10 seconds if the dotnet service crashes:
RestartSec=10
KillSignal=SIGINT
SyslogIdentifier=dotnet20-example
User=nginx
Environment=ASPNETCORE_ENVIRONMENT=Production
Environment=ASPNETCORE_URLS=http://localhost:5000
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false

[Install]
WantedBy=multi-user.target

kestrel-dotnet21-example.service

[Unit]
Description=dotnet21-example

[Service]
WorkingDirectory=/usr/share/nginx/html/dotnet21-example
ExecStart=/usr/bin/dotnet /usr/share/nginx/html/dotnet21-example/dotnet21-example.dll
Restart=always
# Restart service after 10 seconds if the dotnet service crashes:
RestartSec=10
KillSignal=SIGINT
SyslogIdentifier=dotnet21-example
User=nginx
Environment=ASPNETCORE_ENVIRONMENT=Production
Environment=ASPNETCORE_URLS=http://localhost:5001
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false

[Install]
WantedBy=multi-user.target

Step 9 - Configure SELinux

Add the site ports to the whitelist

# Server
semanage port -a -t http_port_t -p tcp 83
semanage port -a -t http_port_t -p tcp 84
# Socket
semanage port -m -t http_port_t -p tcp 5000
semanage port -m -t http_port_t -p tcp 5001

Check the port whitelist

semanage port -l | grep http_port_t

Step 10 - Restart NGINX

systemctl enable nginx
systemctl restart nginx

Step 11 - Restart the custom services

systemctl enable kestrel-dotnet20-example.service kestrel-dotnet21-example.service
systemctl restart kestrel-dotnet20-example.service kestrel-dotnet21-example.service

Step 12 - Setup the firewall

sudo firewall-cmd --permanent --add-port=83/tcp
sudo firewall-cmd --permanent --add-port=84/tcp
sudo firewall-cmd --reload

Troubleshooting

Better upstream access log format
- https://stackoverflow.com/a/26299679
Typical log locations
- /var/log/nginx/error.log

RatserX/centos-rhel-nginx-aspnetcore.md