capistrano postgres db push pull

capistrano-postgres-db-tasks.rb

# config valid only for Capistrano 3.1
lock '3.1.0'

namespace :db do
  desc "Push database"
  task :push do
    run_locally do
      app_server = roles(:app).first
      db_server = 'db.server.example.com'
      user = 'simpleweb'

      raise "No pushing your dev db over production" if env == :production

      local = YAML.load(IO.read("config/database.yml"))["development"]
      remote = YAML.load(capture("ssh -C #{user}@#{app_server} 'cat #{shared_path}/config/database.yml'"))[fetch(:rails_env).to_s]

      execute "
        pg_dump
          --host localhost
          --username #{local["username"]}
          --create
          --format c
          --no-owner
          #{local["database"]}
        |
        ssh -C #{user}@#{db_server} '
          PGPASSWORD=#{remote["password"]}
          pg_restore
            --host localhost
            --username #{remote["username"]}
            --dbname #{remote["database"]}
            --no-owner
        '
      "
      .gsub(/\n/, '')
      .squeeze(' ')
    end
  end

  desc "Pull database"
  task :pull do
    run_locally do
      app_server = roles(:app).first
      db_server = 'db.server.example.com'
      user = 'simpleweb'

      local = YAML.load(IO.read("config/database.yml"))["development"]
      remote = YAML.load(capture("ssh -C #{user}@#{app_server} 'cat #{shared_path}/config/database.yml'"))[fetch(:rails_env).to_s]

      execute "
        ssh -C #{user}@#{db_server} '
          PGPASSWORD=#{remote["password"]}
            pg_dump
              --host localhost
              --username #{remote["username"]}
              --create
              --format c
              --no-owner
              #{remote["database"]}
        '
        |
        pg_restore
          --username #{local["username"]}
          --dbname #{local["database"]}
          --clean
          --no-owner
      "
      .gsub(/\n/, '')
      .squeeze(' ')
    end
  end
end