Creating a Custom Docker image
Dockers on GitHub
Iron.io Docker images can be found on our Dockers GitHub repo. This is starting place, if you’d like to customize your own Docker image.
Instructions for each language may be found by clicking the images below.
Just select the version (if possible), and follow the instructions in “Building this image.” Editing the repo’s DockerFile allows you to add your own customizations.
For more information on how to edit DockerFiles, the official Docker docs are a great companion.