smtp_config.rb

# Parses a URL containing the SMTP Config (Credentials and other options supported)
# Use from application.rb or in environments.
# 
# Example:
#
#   if ENV["SMTP_URL"]
#     config.action_mailer.delivery_method = :smtp
#     config.action_mailer.smtp_settings = SmtpConfig.from_url(ENV["SMTP_URL"])
#   end
#
# Warning: User & Password in the URL need to be encoded with `CGI.encode` to ensure safe URIs (eg. `@` in User or Password)
class SmtpConfig

  class << self

    def is_true?(value)
      value == '1' || value.downcase == 'true'
    end

    def from_url(url)
      uri = URI.parse(url)

      smtp_config = {
        address:    uri.host,
        port:       uri.port,
        user_name:  CGI.unescape(uri.user),
        password:   CGI.unescape(uri.password),
      }
  
      params = Rack::Utils.parse_nested_query(uri.query)
      %w(authentication domain openssl_verify_mode).each do |key|
        unless (value = params[key]).blank?
          smtp_config[key.to_sym] = value
        end
      end

      %w(open_timeout read_timeout).each do |key|
        unless (value = params[key]).blank?
          smtp_config[key.to_sym] = value.to_i
        end
      end

      %w(enable_starttls enable_starttls_auto ssl tls).each do |key|
        unless (value = params[key]).blank?
          smtp_config[key.to_sym] = is_true?(value)
        end
      end

      smtp_config
    end

  end

end