Extract ActionMailbox::PostfixRelayer

Gemfile.lock

@@ -66,7 +66,6 @@ PATH
   remote: .
   specs:
     actionmailbox (0.1.0)
-      http (>= 4.0.0)
       rails (>= 5.2.0)
 
 GEM
@@ -88,21 +87,13 @@ GEM
     builder (3.2.3)
     byebug (10.0.2)
     concurrent-ruby (1.0.5)
+    crack (0.4.3)
+      safe_yaml (~> 1.0.0)
     crass (1.0.4)
-    domain_name (0.5.20180417)
-      unf (>= 0.0.5, < 1.0.0)
     erubi (1.7.1)
     globalid (0.4.1)
       activesupport (>= 4.2.0)
-    http (4.0.0)
-      addressable (~> 2.3)
-      http-cookie (~> 1.0)
-      http-form_data (~> 2.0)
-      http_parser.rb (~> 0.6.0)
-    http-cookie (1.0.3)
-      domain_name (~> 0.5)
-    http-form_data (2.1.1)
-    http_parser.rb (0.6.0)
+    hashdiff (0.3.7)
     i18n (1.1.0)
       concurrent-ruby (~> 1.0)
     jmespath (1.4.0)
@@ -131,6 +122,7 @@ GEM
     rails-html-sanitizer (1.0.4)
       loofah (~> 2.2, >= 2.2.2)
     rake (12.3.1)
+    safe_yaml (1.0.4)
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -143,9 +135,10 @@ GEM
     thread_safe (0.3.6)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
-    unf (0.1.4)
-      unf_ext
-    unf_ext (0.0.7.5)
+    webmock (3.4.2)
+      addressable (>= 2.3.6)
+      crack (>= 0.3.2)
+      hashdiff
     websocket-driver (0.7.0)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.3)
@@ -160,6 +153,7 @@ DEPENDENCIES
   byebug
   rails!
   sqlite3
+  webmock
 
 BUNDLED WITH
    1.16.6

actionmailbox.gemspec

@@ -16,11 +16,11 @@ Gem::Specification.new do |s|
   s.required_ruby_version = ">= 2.5.0"
 
   s.add_dependency "rails", ">= 5.2.0"
-  s.add_dependency "http", ">= 4.0.0"
 
   s.add_development_dependency "bundler", "~> 1.15"
   s.add_development_dependency "sqlite3"
   s.add_development_dependency "byebug"
+  s.add_development_dependency "webmock"
 
   s.files      = `git ls-files`.split("\n")
   s.test_files = `git ls-files -- test/*`.split("\n")

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

lib/tasks/ingress.rake

@@ -2,45 +2,24 @@
 
 namespace :action_mailbox do
   namespace :ingress do
-    desc "Pipe an inbound email from STDIN to the Postfix ingress at the given URL"
+    desc "Pipe an inbound email from STDIN to the Postfix ingress (URL and INGRESS_PASSWORD required)"
     task :postfix do
       require "active_support"
       require "active_support/core_ext/object/blank"
-      require "http"
+      require "action_mailbox/ingresses/postfix/relayer"
 
-      url, password = ENV.values_at("URL", "INGRESS_PASSWORD")
+      url, password, user_agent = ENV.values_at("URL", "INGRESS_PASSWORD", "USER_AGENT")
 
       if url.blank? || password.blank?
-        puts "4.3.5 URL and INGRESS_PASSWORD are required"
+        echo "4.3.5 URL and INGRESS_PASSWORD are required"
         exit 1
       end
 
-      begin
-        response = HTTP.basic_auth(user: "actionmailbox", pass: password)
-          .timeout(connect: 1, write: 10, read: 10)
-          .post(url, body: STDIN.read,
-            headers: { "Content-Type" => "message/rfc822", "User-Agent" => ENV.fetch("USER_AGENT", "Postfix") })
-
-        case
-        when response.status.success?
-          puts "2.0.0 HTTP #{response.status}"
-        when response.status.unauthorized?
-          puts "4.7.0 HTTP #{response.status}"
-          exit 1
-        when response.status.unsupported_media_type?
-          puts "5.6.1 HTTP #{response.status}"
-          exit 1
-        else
-          puts "4.0.0 HTTP #{response.status}"
-          exit 1
+      ActionMailbox::PostfixRelayer.new(url: url, password: password, user_agent: user_agent)
+        .relay(STDIN.read).tap do |result|
+          echo result.output
+          exit result.success? ? 0 : 1
         end
-      rescue HTTP::ConnectionError => error
-        puts "4.4.2 Error connecting to the Postfix ingress: #{error.message}"
-        exit 1
-      rescue HTTP::TimeoutError
-        puts "4.4.7 Timed out piping to the Postfix ingress"
-        exit 1
-      end
     end
   end
 end

test/test_helper.rb

@@ -6,6 +6,7 @@ ActiveRecord::Migrator.migrations_paths = [File.expand_path("../test/dummy/db/mi
 require "rails/test_help"
 
 require "byebug"
+require "webmock/minitest"
 
 Minitest.backtrace_filter = Minitest::BacktraceFilter.new
 

test/unit/postfix_relayer_test.rb

@@ -0,0 +1,80 @@
+require_relative '../test_helper'
+
+require 'action_mailbox/postfix_relayer'
+
+module ActionMailbox
+  class PostfixRelayerTest < ActiveSupport::TestCase
+    URL = "https://example.com/rails/action_mailbox/postfix/inbound_emails"
+    INGRESS_PASSWORD = "secret"
+
+    setup do
+      @relayer = ActionMailbox::PostfixRelayer.new(url: URL, password: INGRESS_PASSWORD)
+    end
+
+    test "successfully relaying an email" do
+      stub_request(:post, URL).to_return status: 204
+
+      result = @relayer.relay(file_fixture("welcome.eml").read)
+      assert_equal "2.0.0 Successfully relayed message to Postfix ingress", result.output
+      assert result.success?
+      assert_not result.failure?
+
+      assert_requested :post, URL, body: file_fixture("welcome.eml").read,
+        basic_auth: [ "actionmailbox", INGRESS_PASSWORD ], headers: { "Content-Type" => "message/rfc822", "User-Agent" => "Postfix" }
+    end
+
+    test "unsuccessfully relaying with invalid credentials" do
+      stub_request(:post, URL).to_return status: 401
+
+      result = @relayer.relay(file_fixture("welcome.eml").read)
+      assert_equal "4.7.0 Invalid credentials for Postfix ingress", result.output
+      assert_not result.success?
+      assert result.failure?
+    end
+
+    test "unsuccessfully relaying due to an unspecified server error" do
+      stub_request(:post, URL).to_return status: 500
+
+      result = @relayer.relay(file_fixture("welcome.eml").read)
+      assert_equal "4.0.0 HTTP 500", result.output
+      assert_not result.success?
+      assert result.failure?
+    end
+
+    test "unsuccessfully relaying due to a gateway timeout" do
+      stub_request(:post, URL).to_return status: 504
+
+      result = @relayer.relay(file_fixture("welcome.eml").read)
+      assert_equal "4.0.0 HTTP 504", result.output
+      assert_not result.success?
+      assert result.failure?
+    end
+
+    test "unsuccessfully relaying due to ECONNRESET" do
+      stub_request(:post, URL).to_raise Errno::ECONNRESET.new
+
+      result = @relayer.relay(file_fixture("welcome.eml").read)
+      assert_equal "4.4.2 Network error relaying to Postfix ingress: Connection reset by peer", result.output
+      assert_not result.success?
+      assert result.failure?
+    end
+
+    test "unsuccessfully relaying due to connection failure" do
+      stub_request(:post, URL).to_raise SocketError.new("Failed to open TCP connection to example.com:443")
+
+      result = @relayer.relay(file_fixture("welcome.eml").read)
+      assert_equal "4.4.2 Network error relaying to Postfix ingress: Failed to open TCP connection to example.com:443", result.output
+      assert_not result.success?
+      assert result.failure?
+    end
+
+    test "unsuccessfully relaying due to an unhandled exception" do
+      stub_request(:post, URL).to_raise StandardError.new("Something went wrong")
+
+      result = @relayer.relay(file_fixture("welcome.eml").read)
+      assert_equal "4.0.0 Error relaying to Postfix ingress: Something went wrong", result.output
+      assert_not result.success?
+      assert result.failure?
+    end
+  end
+end