CircleCI Dockerfile Wizard

Easily build Docker images with different versions/combinations of common languages/dependencies, for use on CircleCI.

Prerequisites

CircleCI account
Docker Hub account (Docker itself does not need to be installed on your computer)
Make & Perl (included in most macOS & Linux installations)

Usage

1. Fork this repository and start building it on CircleCI:

2. Add your Docker Hub username (DOCKER_USERNAME) and password (DOCKER_PASSWORD) to CircleCI, either as project-specific environment variables (shown below), or as resources in your org-global (default) Context

3. Clone your fork of the project onto your computer

4. Enter the cloned dockerfile-wizard directory and run make ready to prepare the config.yml file for building Docker images on CircleCI

5. Run make setup in the cloned directory, or else manually add the versions/dependencies that you need to .circleci/config.yml as specified in the image_config section

6. Commit and push your changes

Once the build has finished, your image will be available at http://hub.docker.com/r/DOCKER_USERNAME/IMAGE_NAME and can be used in other projects building on CircleCI (or anywhere else!). The Dockerfile for your image will be stored as an artifact in this project's build job.

To use the Dockerfile Wizard again, run make reset in the cloned directory, then repeat steps 4-6.

How it works

The setup script adds your requested version information to the config.yml file as environment variables
The generate.sh script runs on CircleCI and generates a Dockerfile based on those environment variables
CircleCI builds your Docker image from the generated Dockerfile, deploys it using your Docker credentials, and then tests your image using Bats, which we install in every Docker image built via this repository

Notes

The portions of this repository that run on your local computer are intended for Linux/macOS operating systems; they may not work on Windows
This repository has not been tested with every possible permutation of versions/dependencies, and you may encounter errors with some combinations of various languages/tools. If your build job fails, check its docker build step—there's likely a compilation error with a particular version of Ruby, Node, or Python.
Thanks to jmason for the tap-to-junit script!
Feedback/questions/bugs welcome!
Want to do all this yourself? Check out our video on creating custom Docker images for CircleCI

To-do