Support API-only Rails apps

[rosa]

This is another take on #87, but without the propshaft dependency that caused a lot of problems for people using Sprockets.

[HLFH]

Using:

gem 'mission_control-jobs', github: 'rails/mission_control-jobs', branch: 'api-mode'

Gives me this error:

bin/rails s
=> Booting Puma
=> Rails 8.0.0 application starting in development 
=> Run `bin/rails server --help` for more startup options
Exiting
/Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/railtie/configuration.rb:109:in `method_missing': undefined method `assets' for an instance of Rails::Application::Configuration (NoMethodError)
Did you mean?  asset_host
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/bundler/gems/mission_control-jobs-9d6a8b3a7902/lib/mission_control/jobs/engine.rb:90:in `block in <class:Engine>'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/initializable.rb:32:in `instance_exec'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/initializable.rb:32:in `run'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/initializable.rb:61:in `block in run_initializers'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/tsort.rb:231:in `block in tsort_each'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/tsort.rb:353:in `block (2 levels) in each_strongly_connected_component'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/tsort.rb:434:in `each_strongly_connected_component_from'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/tsort.rb:352:in `block in each_strongly_connected_component'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/tsort.rb:350:in `each'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/tsort.rb:350:in `call'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/tsort.rb:350:in `each_strongly_connected_component'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/tsort.rb:229:in `tsort_each'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/tsort.rb:208:in `tsort_each'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/initializable.rb:60:in `run_initializers'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/application.rb:440:in `initialize!'
        from /Users/gaspard/Documents/test/vipfishing_gateway/config/environment.rb:5:in `<main>'
        from config.ru:3:in `require_relative'
        from config.ru:3:in `block (2 levels) in <main>'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/rack-3.1.8/lib/rack/builder.rb:108:in `eval'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/rack-3.1.8/lib/rack/builder.rb:108:in `new_from_string'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/rack-3.1.8/lib/rack/builder.rb:97:in `load_file'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/rack-3.1.8/lib/rack/builder.rb:67:in `parse_file'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/rackup-2.2.1/lib/rackup/server.rb:354:in `build_app_and_options_from_config'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/rackup-2.2.1/lib/rackup/server.rb:263:in `app'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/rackup-2.2.1/lib/rackup/server.rb:424:in `wrapped_app'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/commands/server/server_command.rb:76:in `log_to_stdout'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/commands/server/server_command.rb:36:in `start'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/commands/server/server_command.rb:145:in `block in perform'
        from <internal:kernel>:90:in `tap'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/commands/server/server_command.rb:136:in `perform'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/thor-1.3.2/lib/thor/command.rb:28:in `run'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/thor-1.3.2/lib/thor/invocation.rb:127:in `invoke_command'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/command/base.rb:178:in `invoke_command'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/thor-1.3.2/lib/thor.rb:538:in `dispatch'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/command/base.rb:73:in `perform'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/command.rb:65:in `block in invoke'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/command.rb:143:in `with_argv'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/command.rb:63:in `invoke'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/railties-8.0.0/lib/rails/commands.rb:18:in `<main>'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/bundled_gems.rb:75:in `require'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/bundled_gems.rb:75:in `block (2 levels) in replace_require'
        from /Users/gaspard/.asdf/installs/ruby/3.3.5/lib/ruby/gems/3.3.0/gems/bootsnap-1.18.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
        from bin/rails:4:in `<main>'

Reverting to 0.3.2 but happy to try this PR again:

# Active Job dashboard
gem "mission_control-jobs", "0.3.2" # version 0.3.3 is not working with API-only mode
#gem 'mission_control-jobs', github: 'rails/mission_control-jobs', branch: 'api-mode'

[rosa]

Hey @HLFH, you'd need to add propshaft to your Gemfile as well, as instructed in the README change in this PR. I should have added to the PR description, sorry!

[HLFH]

@rosa Ok all good, awesome! Great thank you @rosa.

# Active Job dashboard
gem "mission_control-jobs", github: "rails/mission_control-jobs", branch: "api-mode"
# Deliver assets for Rails: dependency of mission_control-jobs
gem "propshaft"

This PR can be merged.