1 files changed, 60 insertions, 0 deletions
diff --git a/lib/action_mailbox/postfix_relayer.rb b/lib/action_mailbox/postfix_relayer.rb
new file mode 100644
index 0000000000..de4fdc06d0
--- /dev/null
+++ b/lib/action_mailbox/postfix_relayer.rb
@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+require "net/http"
+require "uri"
+require "openssl"
+
+module ActionMailbox
+  class PostfixRelayer
+    class Result < Struct.new(:output)
+      def success?
+        !failure?
+      end
+
+      def failure?
+        output.match?(/\A[45]\.\d\.\d /)
+      end
+    end
+
+    attr_reader :uri, :username, :password, :user_agent
+
+    def initialize(url:, username: "actionmailbox", password:, user_agent: nil)
+      @uri, @username, @password, @user_agent = URI(url), username, password, user_agent || "Postfix"
+    end
+
+    def relay(source)
+      case response = post(source)
+      when Net::HTTPSuccess
+        Result.new "2.0.0 Successfully relayed message to Postfix ingress"
+      when Net::HTTPUnauthorized
+        Result.new "4.7.0 Invalid credentials for Postfix ingress"
+      else
+        Result.new "4.0.0 HTTP #{response.code}"
+      end
+    rescue IOError, SocketError, SystemCallError => error
+      Result.new "4.4.2 Network error relaying to Postfix ingress: #{error.message}"
+    rescue Timeout::Error
+      Result.new "4.4.2 Timed out relaying to Postfix ingress"
+    rescue => error
+      Result.new "4.0.0 Error relaying to Postfix ingress: #{error.message}"
+    end
+
+    private
+      def post(source)
+        client.post uri.path, source,
+          "Content-Type"  => "message/rfc822",
+          "User-Agent"    => user_agent,
+          "Authorization" => "Basic #{Base64.strict_encode64(username + ":" + password)}"
+      end
+
+      def client
+        @client ||= Net::HTTP.new(uri.host, uri.port).tap do |connection|
+          connection.use_ssl      = uri.scheme == "https"
+          connection.verify_mode  = OpenSSL::SSL::VERIFY_PEER
+
+          connection.open_timeout = 1
+          connection.read_timeout = 10
+        end
+      end
+  end
+end