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env.rb

Recap encourages the storage of application configuration (such as database passwords, S3 keys and other things that change between deploys) in environment variables. 12factor.net has a good set of reasons why this is desirable).

To enable this, recap stores these configuration variables in .env, and adds a script to the user’s .profile to set these whenever the environment is loaded (see bootstrap).

Variables can be set in two ways. First, using either the env:set or env:edit tasks, the .env file can be directly manipulated. This is generally the best way to manipulate these values.

The other way to set them is using the set_default_env method directly in your Capfile. This sets a default value, which will be used if no other value is set. An example where this might be useful is where you know your app should run using ruby 1.8.7. Using set_default_env :RBENV_VERSION, “1.8.7-p352” in your Capfile will use this ruby as the default. Then, in a different deployment you might want to test using a different version of ruby, so could use cap env:set RBENV_VERSION=1.9.3-p0 to override the default.

 
require 'recap/tasks'

module Recap::Tasks::Env
  extend Recap::Support::Namespace

  namespace :env do
    set(:environment_file) { "/home/#{application_user}/.env" }

The env task displays the current configuration environment. Note that this doesn’t include all environment variables, only those stored in the .env file.

 
    desc 'View the current server environment'
    task :default do
      if current_environment.empty?
        puts "There are no config variables set"
      else
        puts "The config variables are:"
        puts
        puts current_environment
      end
    end

A single variable can be set using the env:set task, followed by a variable and value, for example cap env:set VARIABLE=VALUE. Variables can be unset using cap env:set VARIABLE=.

 
    desc 'Set a variable in the environment, using "cap env:set VARIABLE=VALUE".  Unset using "cap env:set VARIABLE="'
    task :set do
      env = env_argv.inject(current_environment) do |env, string|
        env.set_string(string)
        logger.debug "Setting #{string}"
        logger.debug "Env is now: #{env}"
        env
      end
      update_remote_environment(env)
      default
    end

The env:edit task uses your EDITOR to load the .env file locally, saving any changes to all servers.

 
    desc 'Edit the server environment'
    task :edit do
      content = edit_file environment_file
      env = Recap::Support::Environment.from_string(content)
      update_remote_environment(env)
      default
    end

The env:reset tasks reverts all variables back to their default values. If there is no default value, the variable will be removed.

 
    desc 'Reset the server environment to its default values'
    task :reset do
      as_app "rm -f #{environment_file}", "~"
      set
    end

    def current_environment
      @current_environment ||= begin
        if deployed_file_exists?(environment_file, '.')
          Recap::Support::Environment.from_string(capture("cat #{environment_file}"))
        else
          Recap::Support::Environment.new
        end
      end
    end

    def update_remote_environment(env)
      logger.debug "Env is now #{env}"

      default_env.each do |name, value|
        env.set(name, value) unless env.get(name)
      end

      if env.empty?
        as_app "rm -f #{environment_file}", "~"
      else
        put_as_app env.to_s, environment_file
      end
    end
  end

Default environment values can be set by a recipe using set_default_env :NAME, ‘VALUE’.

 
  def set_default_env(name, value)
    default_env[name.to_s] = value
  end

  def default_env
    @default_env ||= {}
  end

  def env_argv
    ARGV[1..-1]
  end
end