Rails Environment w/Docker

Rails environment setup for docker with multiple repository sub-folders. Assumes the need for using docker-compose to stand up mulitple rails development environments and be able to clone student's work into folders. Once a repo/project is cloned into the student's directory you can add a dockerfile for their project.

Setup

1. Clone the repository:

  git clone https://github.com/elusive/rails-env.git
  cd rails-env

2. Copy the "new-student" directory and rename for a student or author.

cp -r new-student NEW_NAME

3. cd into the new directory
4. Clone project (rails app) repository inside the directory.
5. Edit the dockerfile for the newly cloned project: a. update ADD statement with correct name of project root directory

  ADD ./PROJ_NAME/ ./

b. update COPY statement with correct name of project root directory

  COPY ./PROJ_NAME/ ./

6. Make similar updates to the docker-compose.yml file in the rails-env directory to include correct folder name for the sub-folder of the student/team member directory you just added and are trying to run the project in.

Dependencies

Each application may need other dependency services, such as a database. Currently most of the student's project for which I made this environment use postgresql. Therefore in the services directory there is a postgres folder with a simple dockerfile used to create the postgres-temp docker image that is used directly in the docker-compose.yml file under the service labeled 'db'. If you need additional services for an app you can create a new folder in services and add a dockerfile for that service. You can then docker build -t NAME . and then use NAME to refer to the service. Or you can update the composition to include the new services dockerfile. An example would be if you needed a redis caching server.

Notes

The point of this project is to be able to reuse the docker-compose file and to re-use a single dockerfile for each sub-folder within the environment. This prevents need to add a dockerfile to the (likely) other person's repository. I created this to be able to quickly pull a mentoring student's repo from git and make a couple small edits and then docker-compose up their application w/o having to worry about what dependencies they have.

Execution of commands

Because of the use of docker-compose we can use the services hosts names and the docker-compose run command to execute any commands we might need to, inside of the dev environment. I.e.:

  docker-compose run web rake db:migrate

Future

Future plans include adding use of docker-compose override files to eliminate editing of files but rather adding a file per student directory that can update the path.

Questions or problems please enter an issue or email me: john.c.gilliland@gmail.com