Convert "wordpress" to use "docker stack deploy" as an initial "stack" foray

[tianon]

Closes #912

Here's an example of what this generates: (and that "Try in PWD" link should actually work!)

... via docker stack deploy or docker-compose

Example stack.yml for wordpress:

version: '3.1'

services:

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

  mysql:
    image: mysql:5.7
    environment:
      MYSQL_ROOT_PASSWORD: example

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).

[tianon]

cc @marcosnils

This takes our existing docker-compose.yml scaffolding and converts it to use docker stack deploy and thus gives us "Try in PWD" in a standard way. 👍

(I've only converted wordpress/docker-compose.yml/wordpress/content.md so far as an initial example.)

[marcosnils]

LGTM!.

[marcosnils]

Thx guys, I'll send a PR to add the currents stacks from the PWD stacks repo here. How does that sound?

[tianon]

As long as they don't refer to any non-official images (https://github.com/docker-library/official-images/blob/b16d43ab480ef45ca309ce3dec192e12e94344ac/README.md#repeatability), that sounds like an OK place to start!

We'll need to update REPO/content.md for each too, so starting with the ones that already have a docker-compose.yml might be an easier bit of low-hanging fruit. 😄

[marcosnils]

@tianon got it. Sad that non-official images can't be used, as for tools like mysql / redis / mongo / etc I found super useful to add a "GUI" container so people can play with it easier. But I understand what you mean and it totally makes sense.

On a different subject, do you also maintain the docker store readme files?. Is there a way we could reach there as well?.

[yosifkit]

We don't directly control them but they should eventually get the changes we push to the Docker Hub.

[tianon]

For mysql (and derivatives), we've got adminer, which works decently well in my experience (and is super lightweight).

[marcosnils]

@tianon thx for the adminer tip. I'll try to change our stacks to use that instead.