# Gemfile
gem "capistrano-nginx-unit"

Require in Capfile.

# Capfile
require "capistrano/nginx-unit"

Defined following tasks.

cap nginx_unit:attach              # Attach listener and application configuration to NGINX Unit
cap nginx_unit:attach_app          # Attach application configuration to NGINX Unit
cap nginx_unit:attach_listener     # Attach listener configuration to NGINX Unit
cap nginx_unit:detach              # Detach listener and application configuration from NGINX Unit
cap nginx_unit:detach_app          # Detach application configuration from NGINX Unit
cap nginx_unit:detach_listener     # Detach listener configuration from NGINX Unit
cap nginx_unit:start               # Start NGINX Unit process
cap nginx_unit:stop                # Stop NGINX Unit process

nginx_unit:attach is main task.
The task sends HTTP request to configure NGINX Unit on server.
When NGINX Unit process received the request, launches rack application process.
If you want to apply new code when deployed, please invoke nginx_unit:attach task after deploy:published.

# deploy.rb
after "deploy:published", "nginx_unit:attach"

set :nginx_unit_roles,        -> { :app }
set :nginx_unit_control_sock, -> { "/var/run/control.unit.sock" }
set :nginx_unit_listen,       -> { "*:3000" }
set :nginx_unit_listener,     -> { { pass: "applications/#{fetch(:nginx_unit_app_name)}" } }
set :nginx_unit_app_name,     -> { fetch(:application) }
set :nginx_unit_processes,    -> { nil }
set :nginx_unit_user,         -> { nil }
set :nginx_unit_group,        -> { nil }
set :nginx_unit_working_dir,  -> { nil }
set :nginx_unit_script,       -> { "config.ru" }
set :nginx_unit_environment,  -> { {} }
set :nginx_unit_limits,       -> { nil }

• :nginx_unit_roles

  Roles to run tasks for NGINX Unit. Default: :app

• :nginx_unit_control_sock

  Path to NGINX Unit's unix domain socket path. Default: "/var/run/control.unit.sock"

• :nginx_unit_listen

  IP Address and port where rack application listens on. Default: "*:3000"
  See Listeners configuration

• :nginx_unit_listener

  Listener configuration of rack application processes. Default: { pass: "applications/#{fetch(:nginx_unit_app_name)}" }
  If you are using NGINX Unit that doesn`t support pass option, you can overwrite this configuration with { application: fetch(:nginx_unit_app_name) }
  (However, application option is currently deprecated.)
  See Listeners configuration

• :nginx_unit_app_name

  Application name.
  See Applications configuration

• :nginx_unit_processes

  Number of rack application processes. Default: 1
  You can also set the Hash that has keys max, spare and idle_timeout.
  See Processes and Limits

• :nginx_unit_user, :nginx_unit_group

  Username and group of rack application process. Default: "nobody"
  See Application Object configuration

• :nginx_unit_working_dir

  Working directory of rack application process. Default: RELEASE_PATH
  See Application Object configuration

• :nginx_unit_script

  Rack application script path. Default: RELEASE_PATH/config.ru
  See Ruby application configuration

• :nginx_unit_environment (NGINX Unit >= 1.2)

  Environment variable setting. Default value is empty.
  This variable accepts Hash. e.g., { "RAILS_ENV" => "production" }.

• :nginx_unit_limits

  Request limits of rack application processes. Default: nil(not specified)
  You can set the Hash that has keys requests and timeout.
  See Processes and Limits