Capistrano Unicorn
Capistrano 3.x plugin that integrates Unicorn tasks into capistrano deployment script. Taken from https://github.com/sosedoff/capistrano-unicorn and adapted to work with Capistrano 3.x.
Note: this code is not well tested, if anything fails, please report it. Use at your own risk.
Developers: Please consider contributing your forked changes, or opening an issue if there is no existing relevant one. There are a lot of forks--we'd love to reabsorb some of the issues/solutions the community has encountered.
Usage
If you are upgrading from a previous version, please see the NEWS file.
Setup
Add the library to your Gemfile:
group :development do
  gem 'sepastian-capistrano3-unicorn', :require => false
endAnd require it in your Capfile:
require 'capistrano/unicorn'Add unicorn restart task hook:
after 'deploy:restart', 'unicorn:reload'    # app IS NOT preloaded
after 'deploy:restart', 'unicorn:restart'   # app preloaded
after 'deploy:restart', 'unicorn:duplicate' # before_fork hook implemented (zero downtime deployments)Create a new configuration file config/unicorn.rb or config/unicorn/STAGE.rb,
where stage is your deployment environment.
Example config - examples/rails3.rb. Please refer to Unicorn documentation for more examples and configuration options.
Deploy
First, make sure you're running the latest release:
cap deploy
Then you can test each individual task:
cap unicorn:start
cap unicorn:stop
cap unicorn:reload
Configuration
You can modify any of the following Capistrano variables in your deploy.rb config.
You can use the unicorn:show_vars task to check that the values you have specified
are set correctly.
Environment parameters
- 
unicorn_env- Set basename of unicorn config.rbfile to be used loaded fromunicorn_config_path. Defaults torails_envvariable if set, otherwiseproduction. - 
unicorn_rack_env- Set the value which will be passed to unicorn via the-Eparameter as the Rack environment. Valid values aredevelopment,deployment, andnone. Defaults todevelopmentifrails_envisdevelopment, otherwisedeployment. 
Execution parameters
- 
unicorn_user- Launch unicorn master as the specified user viasudo. Defaults tonil, which means no use ofsudo, i.e. run as the user defined by theuservariable. - 
unicorn_roles- Define which roles to perform unicorn recipes on. Defaults to:app. - 
unicorn_bundle- Set bundler command for unicorn. Defaults tobundle. - 
unicorn_bin- Set unicorn executable file. Defaults tounicorn. - 
unicorn_options- Set any additional options to be passed to unicorn on startup. - 
unicorn_restart_sleep_time- Number of seconds to wait for (old) pidfile to show up when restarting unicorn. Defaults to 2. 
Relative path parameters
- 
app_subdir- If your app lives in a subdirectory 'rails' (say) of your repository, set this to/rails(the leading slash is required). - 
unicorn_config_rel_path- Set the directory path (relative toapp_path- see below) where unicorn config files reside. Defaults toconfig. - 
unicorn_config_filename- Set the filename of the unicorn config file loaded fromunicorn_config_path. Should not be present in multistage installations. Defaults tounicorn.rb. 
Absolute path parameters
- 
app_path- Set path to app root. Defaults tocurrent_path + app_subdir. - 
unicorn_pid- Set unicorn PID file path. By default, attempts to auto-detect from unicorn config file. On failure, falls back to value inunicorn_default_pid - 
unicorn_default_pid- See above. Defaults to#{current_path}/tmp/pids/unicorn.pid - 
bundle_gemfile- Set path to Gemfile. Defaults to#{app_path}/Gemfile - 
unicorn_config_path- Set the directory where unicorn config files reside. Defaults to#{current_path}/config. 
Zero Downtime Deployment Options
- 
unicorn:restart: 👎 This can sort of support it with a configurable timeout, which may not be reliable. - 
unicorn:reload: ❓ Can anyone testify to its zero-downtime support? - 
unicorn:duplicate: 👍 If you install the Unicornbefore_forkhook, then yes! See: sosedoff#40 (comment) 
Available Tasks
To get a list of all capistrano tasks, run cap -T:
cap unicorn:add_worker                # Add a new worker
cap unicorn:remove_worker             # Remove amount of workers
cap unicorn:reload                    # Reload Unicorn
cap unicorn:restart                   # Restart Unicorn
cap unicorn:show_vars                 # Debug Unicorn variables
cap unicorn:shutdown                  # Immediately shutdown Unicorn
cap unicorn:start                     # Start Unicorn master process
cap unicorn:stop                      # Stop Unicorn
Tests
To execute test suite run:
bundle exec rake test
License
See LICENSE file for details.