Integrating Capistrano 2.x

This is a sample showing how to use the information of your hosts registered to Mackerel as deploy target hosts for Capistrano 2.x.

We will use the mackerel-client gemfile.

Appending the gemfile:

gem 'mackerel-client'

From Capistrano

config/deploy.rb (Capfile):

load 'deploy'

require 'mackerel/client'

set :mackerel_api_key, MACKEREL_API_KEY
set :service, SERVICE_NAME

@client = Mackerel::Client.new(mackerel_api_key: mackerel_api_key)

def host_ip_addrs(role)
  hosts = @client.get_hosts(service: service, roles: role).select do |host|
    host.status === 'standby' || host.status === 'working'
  end.map do |host|
    interface = host.interfaces.find { |i| /^eth/ === i['name'] }
    interface['ipAddress'] if interface
  end.select {|ipaddr| ipaddr != nil }
end

role :app do
  host_ip_addrs(:app)
end

role :db do
  host_ip_addrs(:db)
end

Designate the name of the service registered to Mackerel in SERVICE_NAME.

The hosts that belong to that service in Mackerel can be assigned as Capistrano roles.

Hosts whose statuses are either working or standby can be listed.
As for the host IP addresses, information collected by the agent will be used.

Here we will define the task.

desc "Mackerel integration test"
namespace :deploy do
  desc "echo message"
  task :echo , roles => :app do
    run "echo \"Integration Test\""
  end
end

Executing the task will yield the following results.

# bundle exec cap deploy:echo
  * 2014-09-23 21:36:28 executing `deploy:echo'
  * executing "echo \"Integration Test\""
    servers: ["127.0.0.1"]
    [127.0.0.1] executing command
 ** [out :: 127.0.0.1] Integration Test
    command finished in 435ms