Ubuntu

Docker container used as base for all other Apollo13 docker containers. Contains:

• Ubuntu
• GIT
• Midnight Commander (only for convenience)
• TERM environment variable for flawless run of console applications like mc, nano, ...
• environment initialization script env.sh that:
  • loads settings required to initialize the container from Redis configuration database
  • set the current IP address into environment variables named CONTAINER_IPV4_ADDRESS and CONTAINER_IPV6_ADDRESS

Build of this container is located in private Docker hub repository. In order to use private repositories you must provide your login credentials:

docker login
docker pull apollo13/ubuntu:14.04

docker login needs to be executed just once, as it stores the authentication key in ~/.dockercfg for future uses.

Alternatively you can build the image on your computer by executing the following command in the root directory of the repository:

docker build -t "apollo13/ubuntu:14.04" .

Redis configuration database

A Redis database is required to store configuration settings.

The Redis database contains two types of configuration values:

a) ${SERVER_NAME}_config contains list of settings this container depends on in order to run. The settings list is whitespace separated, and optionally an alias name for the setting can be provided using syntax settingName:aliasName. The settings are loaded into environment variables prefixed by APOLLO13_.

b) ${SERVER_NAME}_${SETTING_NAME} - individual settings, for example: rabbitmq001-master_host

SERVER_NAME should be an environment variable defined in Dockerfile of every container that loads or save configurations settings. The SERVER_NAME environment variable can be overridden when running the container, e.g. the -e parameter of docker run or environment settings of Amazon ECS tasks.

Configuration values can be set from shell scripts by running:

config-service-set "${SERVER_NAME}_${SETTING_NAME}" ${SETTING_VALUE}

Example:

config-service-set "${SERVER_NAME}_host"     "$CONTAINER_IPV4_ADDRESS"
config-service-set "${SERVER_NAME}_user"     "$USER"
config-service-set "${SERVER_NAME}_password" "$PASS"

Production environment

In production environment, connection to Redis database must be setup the following S3 bucket:

s3://apollo13-ecs-config/config-service.sh

Example configuration:

APOLLO13_CONFIG_SERVICE_HOST="redis.m5ki6g.ng.0001.euw1.cache.amazonaws.com"
APOLLO13_CONFIG_SERVICE_PORT=6379
APOLLO13_CONFIG_SERVICE_PASSWORD=""
APOLLO13_CONFIG_SERVICE_DB=1

Redis database from Amazon Elasticache service can be used for the above.

Development environment

Pull and execute redis container:

docker pull apollo13/redis-server
docker run -d -p 6379:6379 --name config-service redis

Link any container using the configuration service with -l (link) parameter while starting the container via docker run, example:

docker run --name rabbitmq-server -d -p 5672:5672 -p 15672:15672 --link config-service:config-service apollo13/rabbitmq-server

GIT integration

The container can automatically launch git pull (and composer install too if composer.json is present) to accomplish launch with the latest code.

To enable this functionality you need to define the following environment variables in Dockerfile of a container derived from apollo13/ubuntu

ENV APOLLO13_GIT_DIRECTORY /var/www/myproject
ENV APOLLO13_GIT_PULL_LATEST true

APOLLO13_GIT_DIRECTORY contains root path to your GIT project inside the container, APOLLO13_GIT_PULL_LATEST enables the actual pulling on launching the container.

In addition to that you must specify GIT branch to be pulled in APOLLO13_GIT_BRANCH environment variable. This should be done when running the container (and not in Dockerfile), so that the docker container can be used for local development.

Running Docker containers on Linux development host

When running Docker on your development host, the TCP/IP ports exposed by Docker may collide with ports of other services already running on your development host. The workaround for this is to run Docker inside a virtual machine using boot2docker.

In local development environment you have to pass environment variable EC2_ENVIRONMENT=false to the container to disable Amazon EC2 specific initialization.

Updating the repository and building the project

This container contains script for updating the GIT repository to the latest version, and for performing subsequent build process (e.g. composer install or npm install).

Script for updating GIT repository discards all local changes and should not be used if you mount your local repository into the container instance. In such case you should only perform build.

To update the repository (discarding all local changes) by pulling the latest revision followed by building of the project, execute:

docker exec -t -i CONTAINER_NAME_OR_ID /env.sh update.sh

To build the project (without pulling the latest revision), execute:

docker exec -t -i CONTAINER_NAME_OR_ID /env.sh build.sh

Launching additional commands on container start

The container can optionally launch additional command on its start if passed via APOLLO13_CONTAINER_ONLAUNCH environment variable. The command is executed in bash.