devshop/role repository overview

⁠DevShop Docker Images

This folder containes all of the various files needed to build the DevShop Docker Images.

⁠Architecture

The DevShop Ansible Roles⁠ are written in Ansible, using Ansible Galaxy roles whenever possible. See the Roles⁠ folder.

The DevShop Docker Images⁠ use the DevShop Ansible Roles to build, so that there is only one set of server configuration to maintain.

The DevShop Docker Images⁠ are designed to support the Ansible Roles, in order to provide consistency between Docker container environments and native Linux environments.

⁠Docker Image Tags

All of the devshop/* containers share the same tags. These tags also serve as the list of supported operating systems.

The tags match the "slugs" for each operating system used by Jeff Geerling⁠ in his Ansible roles. See his Repositories on GitHub⁠ that are named docker-*-ansible.

• latest, ubuntu1804
• centos7

This list will grow as we finish stabilizing the testing system.

⁠DevShop Docker Images

• devshop/base

  The base operating system with as few changes as possible. Prepares environment variables and SystemD for running in a container.

• devshop/ansible

  Base image plus Python, PIP, and Ansible installed. Identical to the geerlingguy/docker-*-ansible containers.

• devshop/role

  Core image plus the tools needed to easily assign containers a role at runtime or build-time. This container is what all other devshop containers are built from.

  This container is designed to self-configure based on environment variables (or Docker's "Build Args", if using at buildtime).

⁠DevShop Role Template

Every DevShop server and container will be based on the devshop/role configuration, which will install:

• The DevShop CLI
• The core DevShop Ansible Roles
• Extra Ansible Roles, if any.
• An Ansible inventory, either local or remote, which includes:
  • The server identity and role.
  • The server's peers.

The devshop/role image is a template for all other server images to be built from.

⁠Docker Environment

This container is magic. It runs SystemD in the backend, but still runs the Docker Command in the init.

⁠Docker Command (DOCKER_COMMAND)

This is the main CMD of the Docker images. By default, it runs whatever is in DEVSHOP_DOCKER_BUILD_COMMAND.

The docker-entrypoint script will keep the containers running after the command passes.

If it fails, it will kill the container, as expected.

⁠DevShop Docker Command (DEVSHOP_DOCKER_RUN_COMMAND)

To allow the container to stay open even if it fails, you can use the DEVSHOP_DOCKER_BUILD_COMMAND variable.