Added fully configured Docker image

[mKeRix]

Hey there,

the previous Docker support didn't quite adhere to Docker principles and made Packages sort of painful to setup on production. I've rewritten the Docker files to generate fully configured instance of the application that can easily be deployed.

You can see the results here: https://hub.docker.com/r/mkerix/packages/

Important tasks after merging

• Add an official automated build on Docker Hub. You can follow the official documentation for this and keep the default settings. In the Build Settings tab of your new project please add a repository link to webdevops/php-nginx.
• Update the links and docker-compose file in the README to reflect your new official Docker image.

Please let me know if you have any questions!

[tyler-sommer]

This is a fantastic idea, thank you for submitting the PR and doing all the leg work. I'll take a look at getting this done for the next release.

Thanks for using Packages!

[htuscher]

Composer is already included in webdevops/php-nginx:7.2 and updated on every image build.

[htuscher]

To keep the amount of image layers as small as possible, you should use:

ENV FOO='Bar' \
         BAR='Baz'

[htuscher]

The webdevops image contains a helpful wrapper apt-install gettext-base procps which updates, installs and cleans afterwards.

[htuscher]

Reduce number of image layers also here by executing concatenated RUN commands

[htuscher]

You should add a supervisord service for the resque worker and there's also a mechanism for doing startup commands in the docker container: service.d scripts.