Launch School: Ruby project template

Use this template for basic Ruby projects that will run in a Docker container, which ensures consistency and portability.

Dev Container

Projects based on this template will use Docker to quickly provide a consistent cross-platform Ruby development environment using the latest version of Ruby 3.

If you need a container for production use, consider the official Docker Ruby image as a starting point.

Pre-requisites (Mac, Windows 10/11, Linux)

1. Install Visual Studio Code.
2. If Windows 10, install and configure WSL2. If Windows 11, search for a guide to do the same.
3. If Mac, hit Shift-Command-P, type Shell Command, and select Shell Command: Install 'code' command in PATH option.
   1. It's also essential to drag VS Code into the Applications folder.
4. Install Docker Desktop.
   • If Windows 10: enable the WSL2 integration for best performance.
5. Install the VS Code Remote Containers extension.

Build and run

1. Copy the following to a project's root folder:
   1. .devcontainer folder
      • TODOS:

        • In the devcontainer.json file in this folder, edit the "name" property to something that makes sense for the project.

        • Add a .env file containing following variables (make sure that file is excluded via .gitignore):

          POSTGRES_USER=app_dev
          POSTGRES_PASSWORD=REPLACE_with_your_secure_password!
          

          • Note: the user and password above will only be set when initially creating the postgres-data Docker volume. Rebuilding the container does not delete the volume, and so would not change the initial password if you simply change your .env file. To change the password after initial creation, use psql or another admin tool, then update your .env for next time. Or, delete the container and then the postgres-data Docker volume if it doesn't contain needed data, then rebuild the container.
          • The same username and password are used when postCreateCommand.sh creates a password file, ~/.pgpass, which enables automatic local psql logins. See PSQL for details.
      • Dockerfile declaratively defines container build, including Ruby v3-bullseye, rvm, zsh, Gems, Pry configuration, and more.
      • devcontainer.json configures VS Code and coordinates Docker Compose.
      • docker-compose.yml configures:
        • Shared network
        • Ruby dev container (service)
        • PostgreSQL database container
      • .vscode folder. If you need to make persistent changes to the contents of this folder, or to anything else in this repository, be sure to fork or copy this repo and modify there for your purposes. This folder will completely replace anything in {workspaceFolder}/.vscode when the container is created or rebuilt.
      • .pryrc: pry Gem configuration. Copied to home folder via postCreateCommand.sh.
      • postCreateCommand.sh: devcontainer.json's postCreateCommand executes this after the container is created.
        • Add custom commands to the postCreateCommandCustom.sh file, which postCreateCommand.sh will execute when it's finished. It includes some common ones you can uncomment and customize.
   2. src folder
      • Create or clone code repos here.
      • VS Code uses this folder the Workspace folder, which is the Explorer root.
2. Navigate to the project folder that contains the .devcontainer folder in your (Linux) shell, then enter code .. Visual Studio will prompt you to open the folder in a dev container, automatically building the image if it doesn't already exist and opening the src folder.
   • Clone one or more repositories to the src folder.
   • Your project files will automatically sync between the container and your host file system, so the container can restart without data loss.
   • Consider incorporating the container configuration into specific projects that need customized containers, in which case open those projects in a separate VS Code window that runs in its own container.

Install and run a specific Ruby version with rvm

1. Install with a command like this: rvm install ruby-x.x.x (ruby-major.minor.patch)
2. Set the default Ruby version with a command like this: rvm --default use ruby-x.x.x
3. Revert to the system-default Ruby version (run Ruby programs without rvm): rvm --default use system

Debug

This template is configured to support both pry/pry-byebug (REPL debugger) and VS Code debugging out of the box.

Debug with pry-byebug

It's worth knowing how to debug using the REPL-based Pry, especially Pry-ByeBug, because the VS Code debugger may not do everything you need it to do, especially with complex or remote dev environments.

Learn more here.

Debug with VS Code

Hit F5 to begin debugging the focused open file using the default configuration.

VS Code offers a number of advantages over REPL-based debugging, such as:

• Streamlined and source code-integrated debugging experience: hover over source code variables to view values.
• Set temporary breakpoints and start debugging with a quick F5 press; no need to modify source code with require 'pry' and binding.pry statements.
• View a list of variables and their values in a breakpoint's scope.

Learn more here.

Connect to PostgreSQL

PSQL

Usually, one interacts with a database server remotely using a client. PSQL is one of those clients. This container installs postgresql-client to enable that.

• Secure login is configured using the POSTGRES_USER and POSTGRES_PASSWORD values specified in your .env file is configured during dev environment creation with the creation of a ~/.pgpass password file.
  • More information here.
• Dev container setup adds a custom command to simplify that connection to a single command: dpsql.

PSQL documentation

dpsql command list

• dpsql: connect to Postgres via psql with .env-specifed username and default host (db) + port (5432).
• dpsql --show-command: show the command that would execute.
• dpsql [any psql commands]: all arguments are forwarded to psql.
  • The same is available for createdb (use dcreatedb) and dropdb (use ddropdb).

Create your own Ruby dev container

After completing the pre-requisites above:

1. Hit F1 (Show All Commands shortcut) | Type/select: >Remote-Containers: Add Development Container Configuration Files...
2. Type Ruby and select it.
   • There's also Ruby on Rails and others; select Show All Definitions..., then search again to view.
3. Select a version.
4. Customize the dev container, including VS Code settings, to your liking.

Learn more

• Develop with containers (Microsoft)