Ruby dev container json template

devcontainer.json

// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
// https://github.com/microsoft/vscode-dev-containers/tree/v0.224.2/containers/docker-existing-docker-compose
// If you want to run as a non-root user in the container, see .devcontainer/docker-compose.yml.
{
  "name": "Existing Docker Compose (Extend)",
  // Update the 'dockerComposeFile' list if you have more compose files or use different names.
  // The .devcontainer/docker-compose.yml file contains any overrides you need/want to make.
  "dockerComposeFile": [
    "../docker-compose.yml",
    "docker-compose.yml"
  ],
  // The 'service' property is the name of the service for the container that VS Code should
  // use. Update this value and .devcontainer/docker-compose.yml to the real service name.
  "service": "app",
  // The optional 'workspaceFolder' property is the path VS Code should open by default when
  // connected. This is typically a file mount in .devcontainer/docker-compose.yml
  "workspaceFolder": "/app",
  // Set *default* container specific settings.json values on container create.
  // Add the IDs of extensions you want installed when the container is created.
  "customizations": {
    "vscode": {
      "settings": {},
      "extensions": [
        "rebornix.ruby",
        "castwide.solargraph",
        "eamodio.gitlens",
      ]
    }
  },
  // Use 'forwardPorts' to make a list of ports inside the container available locally.
  // "forwardPorts": [],
  // Uncomment the next line if you want start specific services in your Docker Compose config.
  // "runServices": [],
  // Uncomment the next line if you want to keep your containers running after VS Code shuts down.
  // "shutdownAction": "none",
  // Uncomment the next line to run commands after the container is created - for example installing curl.
  "postStartCommand": "git config --global --add safe.directory ${containerWorkspaceFolder}"
  // Uncomment to connect as a non-root user if you've added one. See https://aka.ms/vscode-remote/containers/non-root.
  // "remoteUser": "vscode"
}

docker-compose.yml

version: '3.9'
services:
  # Update this to the name of the service you want to work with in your docker-compose.yml file
  app:
    # If you want add a non-root user to your Dockerfile, you can use the "remoteUser"
    # property in devcontainer.json to cause VS Code its sub-processes (terminals, tasks, 
    # debugging) to execute as the user. Uncomment the next line if you want the entire 
    # container to run as this user instead. Note that, on Linux, you may need to 
    # ensure the UID and GID of the container user you create matches your local user. 
    # See https://aka.ms/vscode-remote/containers/non-root for details.
    #
    # user: vscode

    # Uncomment if you want to override the service's Dockerfile to one in the .devcontainer 
    # folder. Note that the path of the Dockerfile and context is relative to the *primary* 
    # docker-compose.yml file (the first in the devcontainer.json "dockerComposeFile"
    # array). The sample below assumes your primary file is in the root of your project.
    #
    build:
      context: .
      dockerfile: .devcontainer/Dockerfile

    # volumes:
      # Update this to wherever you want VS Code to mount the folder of your project
      # - .:/app:cached

      # Uncomment the next line to use Docker from inside the container. See https://aka.ms/vscode-remote/samples/docker-from-docker-compose for details.
      # - /var/run/docker.sock:/var/run/docker.sock 

    # Uncomment the next four lines if you will use a ptrace-based debugger like C++, Go, and Rust.
    # cap_add:
    #   - SYS_PTRACE
    # security_opt:
    #   - seccomp:unconfined

    # Overrides default command so things don't shut down after the process ends.
    # command: /bin/sh -c "while sleep 1000; do :; done"
 

Dockerfile

FROM yourrepo-app:latest

RUN apk --update add openssh-client
RUN echo '.devcontainer/' > ~/.gitignore
RUN gem install solargraph --no-document
RUN bundle exec rubocop --start-server