wordpress

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The WordPress rich content management system can utilize plugins, widgets, and themes.

GitHub repo: https://github.com/docker-library/wordpress

Library reference

This content is imported from the official Docker Library docs, and is provided by the original uploader. You can view the Docker Store page for this image at https://store.docker.com/images/wordpress

Supported tags and respective Dockerfile links

Quick reference

What is WordPress?

WordPress is a free and open source blogging tool and a content management system (CMS) based on PHP and MySQL, which runs on a web hosting service. Features include a plugin architecture and a template system. WordPress is used by more than 22.0% of the top 10 million websites as of August 2013. WordPress is the most popular blogging system in use on the Web, at more than 60 million websites. The most popular languages used are English, Spanish and Bahasa Indonesia.

wikipedia.org/wiki/WordPress

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How to use this image

$ docker run --name some-wordpress --link some-mysql:mysql -d wordpress

The following environment variables are also honored for configuring your WordPress instance:

  • -e WORDPRESS_DB_HOST=... (defaults to the IP and port of the linked mysql container)
  • -e WORDPRESS_DB_USER=... (defaults to “root”)
  • -e WORDPRESS_DB_PASSWORD=... (defaults to the value of the MYSQL_ROOT_PASSWORD environment variable from the linked mysql container)
  • -e WORDPRESS_DB_NAME=... (defaults to “wordpress”)
  • -e WORDPRESS_TABLE_PREFIX=... (defaults to “”, only set this when you need to override the default table prefix in wp-config.php)
  • -e WORDPRESS_AUTH_KEY=..., -e WORDPRESS_SECURE_AUTH_KEY=..., -e WORDPRESS_LOGGED_IN_KEY=..., -e WORDPRESS_NONCE_KEY=..., -e WORDPRESS_AUTH_SALT=..., -e WORDPRESS_SECURE_AUTH_SALT=..., -e WORDPRESS_LOGGED_IN_SALT=..., -e WORDPRESS_NONCE_SALT=... (default to unique random SHA1s)

If the WORDPRESS_DB_NAME specified does not already exist on the given MySQL server, it will be created automatically upon startup of the wordpress container, provided that the WORDPRESS_DB_USER specified has the necessary permissions to create it.

If you’d like to be able to access the instance from the host without the container’s IP, standard port mappings can be used:

$ docker run --name some-wordpress --link some-mysql:mysql -p 8080:80 -d wordpress

Then, access it via http://localhost:8080 or http://host-ip:8080 in a browser.

If you’d like to use an external database instead of a linked mysql container, specify the hostname and port with WORDPRESS_DB_HOST along with the password in WORDPRESS_DB_PASSWORD and the username in WORDPRESS_DB_USER (if it is something other than root):

$ docker run --name some-wordpress -e WORDPRESS_DB_HOST=10.1.2.3:3306 \
    -e WORDPRESS_DB_USER=... -e WORDPRESS_DB_PASSWORD=... -d wordpress

… via docker stack deploy or docker-compose

Example stack.yml for wordpress:

version: '3.1'

services:

  wordpress:
    image: wordpress
    restart: always
    ports:
      - 8080:80
    environment:
      WORDPRESS_DB_PASSWORD: example

  mysql:
    image: mysql:5.7
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: example

Try in PWD

Run docker stack deploy -c stack.yml wordpress (or docker-compose -f stack.yml up), wait for it to initialize completely, and visit http://swarm-ip:8080, http://localhost:8080, or http://host-ip:8080 (as appropriate).

Adding additional libraries / extensions

This image does not provide any additional PHP extensions or other libraries, even if they are required by popular plugins. There are an infinite number of possible plugins, and they potentially require any extension PHP supports. Including every PHP extension that exists would dramatically increase the image size.

If you need additional PHP extensions, you’ll need to create your own image FROM this one. The documentation of the php image explains how to compile additional extensions. Additionally, the wordpress Dockerfile has an example of doing this.

The following Docker Hub features can help with the task of keeping your dependent images up-to-date:

  • Automated Builds let Docker Hub automatically build your Dockerfile each time you push changes to it.
  • Repository Links can ensure that your image is also rebuilt any time wordpress is updated.

Image Variants

The wordpress images come in many flavors, each designed for a specific use case.

wordpress:<version>

This is the defacto image. If you are unsure about what your needs are, you probably want to use this one. It is designed to be used both as a throw away container (mount your source code and start the container to start your app), as well as the base to build other images off of.

wordpress:alpine

This image is based on the popular Alpine Linux project, available in the alpine official image. Alpine Linux is much smaller than most distribution base images (~5MB), and thus leads to much slimmer images in general.

This variant is highly recommended when final image size being as small as possible is desired. The main caveat to note is that it does use musl libc instead of glibc and friends, so certain software might run into issues depending on the depth of their libc requirements. However, most software doesn’t have an issue with this, so this variant is usually a very safe choice. See this Hacker News comment thread for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.

To minimize image size, it’s uncommon for additional related tools (such as git or bash) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the alpine image description for examples of how to install packages if you are unfamiliar).

wordpress:cli

This image variant does not contain WordPress itself, but instead contains WP-CLI.

The simplest way to use it with an existing WordPress container would be something similar to the following:

$ docker run -it --rm \
	--volumes-from some-wordpress \
	--network container:some-wordpress \
	wordpress:cli user list

Generally speaking, for WP-CLI to interact with a WordPress install, it needs access to the on-disk files of the WordPress install, and access to the database (and the easiest way to accomplish that such that wp-config.php does not require changes is to simply join the networking context of the existing and presumably working WordPress container, but there are many other ways to accomplish that which will be left as an exercise for the reader).

library, sample, wordpress