capistrano-monorepo

Capistrano tasks for working with a monorepo.

Introduction

This plugin is a set of tasks designed to make interacting and deploying a set of folders, each representing a single set of isolated code or module, within a single repository (also called a 'monorepo'), using Capistrano.

Each of the subcomponents of the monorepo is typically deployed by setting :repo_tree in the appropriate <stage>.rb file.

Installation

If not using bundler, run:

gem install capistrano-monorepo

If using bundler, then in your Gemfile, add the following line:

group :development do
  ...
  gem 'capistrano-monorepo'
end

and run:

bundle install

Components

Currently, the gem is composed of a single component, the assets component.

New components are encouraged. Please submit an issue and a PR after reading CONTRIBUTING.md.

assets

The assets component is designed to allow for the deployment of assets from a top-level folder within the monorepo into a subfolder during deployment.

Consider the following: If our monorepo contains a top level directory called assets, where all images (and possibly other assets, such as stylesheets) are stored, plus a top level directory called app which contains a Rails application and depends on assets, we might have the following file structure when working locally:

- app/
  - assets/
    - images/ -> symlink to ../../assets/images
- assets/
  - images/
    - background.png
    - logo.svg
    - ...

While this works when developing, once we deploy with :repo_tree set to the path for app, we quickly realize that only the app directory is deployed. As such, the link in app/assets/images is broken, because on the deployment target system, ../../assets/images doesn't exist.

The assets component of capistrano-monorepo solves this by doing two things:

1. It removes any existing references to a specified assets folder within the deployed repository.
2. It checks out a specified assets folder from the top level of the monorepo and deploys it in a specified location in the deployment target repo.

Configuration

In your deploy/<stage>.rb file, add the following:

# This is an array that contains all of your asset paths. They must be unique
# (so you can't have multiple asset paths that point to the same target path)
set :monorepo_asset_paths, [
    {
        # This is the path within the deployment target where you want to deploy the
        # assets directory. For a Rails app, this will almost always be app/assets/
        asset_path: "path/to/assets/target/directory",
        
        # This is the name of the top level directory in the monorepo where the assets
        # are located.
        asset_source: "assets"
    }
]

Next, in your deploy.rb file, specify where in your pipeline you want the deployment to happen:

after 'git:create_release', 'monorepo:import_assets'

To test, run cap <stage> deploy --dry-run and verify that monorepo:import_assets would be executed and that the paths look correct.