Docker WordPress, NGINX+SSL, MariaDB Database.

Description

Fork of Ron Amosa's dockerized wordpress setup with an NGINX reverse-proxy frontend doing the SSL termination, and a standard MariaDB database backend.

There are several changes in this fork.

1. The original project assumed the user already had a local Certificate Authority, as many users won't, the certificates and shell script are replaced in this fork by this step by step guide on Delicious Brains explaining how to generate everything you need for SSL in a local development environment.
2. The Nginx default.conf configuration had breaking syntax preventing Nginx from running which is resolved.
3. The wordpress service in Docker Compose has a small modification that prevents 'critical errors' being reported in WordPress Site Health tests introduced in WordPress 5.2.
4. The MySQL database has been replaced by MariaDB.
5. All but one of the header directives in the Nginx default.conf are removed as the WordPress codex only stipulates the one header for a reverse proxy.

Pre-requisites

• docker installed locally
• docker-compose installed locally

Setup

Follow the instructions on Delicious Brains to create a local certificate authority and certificates, if you choose to use different filenames to those listed below you will need to update their paths in Docker Compose and Nginx.

On completing the guide you should end up with the six files listed below. Each file has a *.example placeholders in the relevant directories where they should be saved. Please note these *.example files are just empty placeholders and won't work, you need to follow the guide.

• my_wpress_site.crt
• my_wpress_site.csr
• my_wpress_site.ext
• my_wpress_site.key
• myCA.key
• myCA.pem

Once you have completed the guide, installed the certificate authorities in your host OS and edited your OS hosts file to include your hostname e.g. wordpress.localhost then:

1. Copy the certs/my_wpress_site.crt and certs/my_wpress_site.key to nginx/ssl/, note that the file my_wpress_site.crt replaces my_wpress_site.cert from the original project.
2. Enter docker-compose up --detach and if one or more of the containers doesn't run examine its logs for errors.

Hostname

The default hostname www.mywordpress.local in the original project is renamed to wordpress.localhost in this fork, 'www' is largely deprecated and the top level domain .local is not reserved for local development whereas '.localhost' is.

You will need to add your hostname e.g. wordpress.localhost to your system hosts file. In my case that means adding it to the Windows hosts file where my browser runs and the Ubuntu hosts file in WSL2 where I run Docker.

127.0.0.1 wordpress.localhost

If all went well you should be able to open a browser at https://wordpress.localhost where you will be greeted (if this is the first time running) with a page asking you to install wordpress.

Key Points

The following node in the wordpress service of Docker Compose resolves failing WordPress Site Health tests which make loopback requests to localhost inside the Docker wordpress service instead of localhost on the host and therefore through the reverse proxy.

extra_hosts:
- wordpress.localhost:172.17.0.1

In the Nginx proxy pass directive, 'wordpress' refers to the name of your wordpress service in your docker-compose.yml file:

proxy_pass http://wordpress;

The following Nginx directive configures WordPress behind a reverse proxy:

proxy_set_header    X-Forwarded-Proto https;

The following conditional in your wp-config.php references the Nginx X-Forwarded-Proto header above so WordPress can determine SSL requests behind a reverse proxy, see the official WordPress codex for more information.

if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https') {
    $_SERVER['HTTPS'] = 'on';
}