Setting up a dev environment

Quick start with Vagrant

For convenience, the Mastodon repository includes a Vagrantfile for quickly setting up a development environment without manual configuration. To use this development environment, install Vagrant using a binary executable or through your package manager.

Once you have Vagrant installed, for convenience, it is recommended to install a plugin to automatically update your machine’s hosts file. This will allow you to access the dev environment at http://mastodon.local without manually editing the hosts file yourself. To do so:

vagrant plugin install vagrant-hostsupdater

The virtual machine can then be started:

vagrant up

Once the virtual machine has been started, you may launch the Foreman task executor to launch the various Mastodon processes:

vagrant ssh -c "cd /vagrant && foreman start"

Once the Mastodon processes have fully started up, you can load http://mastodon.local in your browser to access the Mastodon instance within the VM. You can log in as the default admin user with the username admin@mastodon.local and the password mastodonadmin.

Any changes to the source code will be reflected after saving your files.

To reset the VM to a fresh state, you can destroy it and bring it up again:

vagrant destroy
vagrant up

Manual install from source

You can follow the pre-requisites instructions from the production guide, but do not create a mastodon user. You also don’t have to install nginx, certbot and python-certbot-nginx as the development environment brings its own webserver. Setting up and running a development environment has been proven successful over WSL2 as well if you are on Windows.

Setup

Run the following commands in the project directory:

bundle install
yarn install

In the development environment, Mastodon will use PostgreSQL as the currently signed-in Linux user using the ident method. Ensure that you have created a Postgres user and database for your current signed-in user:

sudo -u postgres createuser $YOUR_USERNAME_HERE --createdb

You can now create the databases mastodon_development and mastodon_test, load the schema into them, and create seed data defined in db/seeds/ into mastodon_development.

rails db:setup

You can now launch http://localhost:3000 in your browser and log in with the default admin user (admin@localhost:3000 / mastodonadmin).

Running

There are multiple processes that need to be run for the full set of Mastodon’s functionality, although they can be selectively omitted. To run all of them with just one command, you can install and use Foreman:

gem install foreman --no-document
foreman start

This will start processes defined in Procfile.dev, which will give you: A Rails server, a Webpack server, a streaming API server, and Sidekiq. Of course, you can run any of those things stand-alone depending on your needs.

Useful commands for testing

rspec

Run the Ruby test suite

yarn run test

Run the JavaScript test suite

rubocop

Check the Ruby code for conformance with our code style

Updating your development instance

bundle install

Update Ruby gems and install any new dependencies

yarn install

Update Javascript packages and install any new dependencies

RAILS_ENV=development rails db:migrate

Run new database migrations for your development instance’s database