This thread discusses the setup and troubleshooting of Discourse development environments using Dev Containers, primarily within VS Code. The original guide outlines the standard process: installing VS Code and the Dev Containers extension, cloning the repository, and using the command palette to open the folder in a container. Key steps include running the default build task to install dependencies and migrate the database, followed by the dev/admin/create task to generate an admin account. Users can then access the instance at localhost:3000. user1
Several users shared specific tips and solutions for common issues. JogiJonas noted that the admin account is not created automatically during the build task and suggested running rake admin:create manually. Arkshine advised Windows users to use “Clone in Volume” to avoid line ending errors. dsims shared a method for mounting plugin directories via devcontainer.json.
Advanced configuration was discussed by gormus, who provided instructions for using OrbStack on macOS to enable HTTPS with custom domains by updating RAILS_DEVELOPMENT_HOSTS and adding entries to /etc/hosts. Eviepayne provided CLI-based instructions for non-VS Code users, detailing how to build, run, and access the container using the devcontainer CLI. However, dfabulich reported that these CLI instructions failed on macOS due to port forwarding issues with ember-cli. They recommended using the legacy boot_dev script for macOS users outside of VS Code, as the CLI does not automatically manage port forwarding. Eviepayne clarified that their instructions were for Linux, leading to a technical debate about Docker’s implementation on macOS versus Linux, with dfabulich explaining that Docker Desktop on macOS runs a virtual machine, which causes the observed differences in network behavior.
Dev Containers is an open standard for configuring a development environment inside a container. This almost entirely eliminates the need to install/configure Discourse-specific tools/dependencies on your local machine, and makes it very easy to keep up-to-date as Discourse evolves over time.
Dev Containers can be used in a number of different IDEs, or directly using their reference CLI. This guide will describe the setup process for VSCode.
In VSCode, use File → Open Folder, then choose the Discourse directory
Open the folder in its Dev Container. This can be done via the popup prompt, or by opening the command palette (Cmd/Ctrl + Shift + P) and searching for “Open folder in container…”
If this is your first time launching a container, you will be prompted to install and start Docker Desktop. Once complete, go back to VSCode re-run “Open folder in container…”
Wait for the container to download and start. When it’s done, the README will appear, and you’ll see the Discourse filesystem in the sidebar.
Run the default build task using Cmd/Ctrl + Shift + B.
This will install dependencies, migrate the database, and start the server. It’ll take a few minutes, especially on the lower-end machines. You’ll see “Build successful” in the terminal when it’s done.
Run the dev/admin/create task. Open the command palette and search for “Tasks: Run Tasks”. It will present a menu of tasks; select dev/admin/create off of that list. You’ll be prompted to enter an email address and a password for your admin user.
Visit http://localhost:3000 in your browser to see your new Discourse instance
All done! You can now make changes to Discourse’s source code and see them reflected in the preview.
Running tests
The first time you run tests, you’ll need to install testing dependencies, including Playwright and the discourse_test DB. You can run the deps/testing task to install those. Open the command palette, select “Tasks: Run Tasks”. It will present a menu of tasks; select deps/testing off of that list.
Every so often, the devcontainer config and the associated container image will be updated. VSCode should prompt you to “rebuild” to apply the changes. Alternatively, you can run “Dev Containers: Rebuild Container” from the VSCode command palette. The working directory, and your Redis/Postgres data will be preserved across rebuilds.
If you’d like to start from scratch with fresh database, you’ll need to delete the discourse-pg and discourse-redis docker volumes. This can be done from the “Remote Explorer” tab of the VSCode sidebar.
Discourse’s sample vscode .vscode/settings.json and .vscode/tasks.json will be copied when you first boot the codespace. From that point forward, if you want to use the latest sample config, you’ll need to manually copy .vscode/settings.json.sample to .vscode/settings.json.
[23963 ms] Start: Run in container: /bin/sh -c ./.devcontainer/scripts/start.rb
/usr/bin/env: ‘ruby\r’: No such file or directory
/usr/bin/env: use -[v]S to pass options in shebang lines
