devilbox/docs/support/hacking.rst

Hacking

This section is all about customizing the Devilbox and its Docker images specifically to your needs.

Table of Contents

local

Rebuilding Docker images

The Devilbox Docker images are rebuilt frequently and automatically pushed to Dockerhub. However there might be cases in which you want to rebuild right away in order to use have custom tools installed or of any other reason.

How to rebuild?

MySQL and Web server images

All MySQL (including MariaDB and PerconaDB) images as well as the web server images provide shell scripts that makes rebuilding the image very simple.

Each of those repositores contain two shell scripts for building normally and rebuilding without cache:

• build/docker-build.sh
• build/docker-rebuild.sh

So you basically just clone the corresponding repository to your computer, edit the Dockerfile to your needs and run one of the scripts.

The following shows an example for Apache 2.2

# Clone the repository and enter its directory
host> git clone https://github.com/devilbox/docker-apache-2.2
host> cd docker-apache-2.2

# Edit the Dockerfile to your needs
host> vi Dockerfile

# Build the Docker image
host> ./build/docker-build.sh

PHP-FPM images

The repository for PHP Docker images contains all version and hence multiple Dockerfiles. The build procedure is slightly different as those Dockerfiles are generated via Ansible build afterwards. Refer to its original repository for more detailed instructions.

A very basic description is as follows:

# Clone the repository and enter its directory
host> git https://github.com/devilbox/docker-php-fpm
host> cd docker-php-fpm

# Edit the Dockerfile template for the 'work' images
host> vi build/ansible/DOCKERFILES/Dockerfile-work.j2

# Generate the actual Dockerfiles
host> make generate

# Build one specific PHP version (in this case PHP 5.5)
host> make build-work-55

How to use the rebuild images?

For the PHP-FPM images you do not have to do anything, as they are built with the image tag that is already present in docker-compose.yml. For all other images you might have to adjust the image tag in docker-compose.yml as all images will be built with the latest tag by default.

If you have built Apache 2.2 for example, open the docker-compose.yml file inside the Devilbox git directory and ensure that the current image tag is replaced with latest.

How it could look by default:

httpd:
  image: devilbox/${HTTPD_SERVER:-nginx-stable}:0.13

How it should look with latest tag:

httpd:
  image: devilbox/${HTTPD_SERVER:-nginx-stable}:latest

Adding your own Docker image

The Devilbox is at its core just a docker-compose.yml file which easily gives you the option to add other Docker images it is currently lacking.

What information do you need?

1. A name, which you can use to refer in the docker-compose command
2. The Docker image name itself
3. The Docker image tag
4. An unused IP address from the devilbox network (found inside docker-compose.yml)

How to add the image?

General example

Open docker-compose.yml with your favourite editor and paste the following snippet below the services: line with one level of indentation:

services:
  # Your custom Docker image here:
  <name>:
    image: <image-name>:<image-version>
    networks:
      app_net:
        ipv4_address: <unused-ip-address>
    # For ease of use always automatically start these:
    depends_on:
      - bind
      - php
      - httpd
  # End of custom Docker image

Cockroach DB example

Gather the requirements for the Cockroach DB Docker image:

1. Name: cockroach
2. Image: cockroachdb/cockroach
3. Tag: latest
4. IP: 172.16.238.200

Now add the information to docker-compose.yml just below the services: line:

services:
  # Your custom Docker image here:
  cockroach:
    image: cockroachdb/cockroach:latest
    networks:
      app_net:
        ipv4_address: 172.16.238.200
    # For ease of use always automatically start these:
    depends_on:
      - bind
      - php
      - httpd
  # End of custom Docker image

How to start the new service?

The following will bring up your service including all of its dependent services, as defined with depends_on (bind, php and httpd). You need to replace <name> with the name you have chosen.

host> docker-compose up <name>