Merge pull request #34907 from wildbit/actionmailbox-postmark

Add Postmark ingress support to ActionMailbox

6 files changed, 197 insertions, 33 deletions

diff --git a/actionmailbox/app/controllers/action_mailbox/ingresses/postmark/inbound_emails_controller.rb b/actionmailbox/app/controllers/action_mailbox/ingresses/postmark/inbound_emails_controller.rb
new file mode 100644
index 0000000000..ec4e0da5ec
--- /dev/null
+++ b/actionmailbox/app/controllers/action_mailbox/ingresses/postmark/inbound_emails_controller.rb
@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+
+module ActionMailbox
+  # Ingests inbound emails from Postmark. Requires +RawEmail+ parameter containing a full RFC 822 message.
+  #
+  # Authenticates requests using HTTP basic access authentication. The username is always +actionmailbox+, and the
+  # password is read from the application's encrypted credentials or an environment variable. See the Usage section below.
+  #
+  # Note that basic authentication is insecure over unencrypted HTTP. An attacker that intercepts cleartext requests to
+  # the Postmark ingress can learn its password. You should only use the Postmark ingress over HTTPS.
+  #
+  # Returns:
+  #
+  # - <tt>204 No Content</tt> if an inbound email is successfully recorded and enqueued for routing to the appropriate mailbox
+  # - <tt>401 Unauthorized</tt> if the request's signature could not be validated
+  # - <tt>404 Not Found</tt> if Action Mailbox is not configured to accept inbound emails from Postmark
+  # - <tt>422 Unprocessable Entity</tt> if the request is missing the required +RawEmail+ parameter
+  # - <tt>500 Server Error</tt> if the ingress password is not configured, or if one of the Active Record database,
+  #   the Active Storage service, or the Active Job backend is misconfigured or unavailable
+  #
+  # == Usage
+  #
+  # 1. Tell Action Mailbox to accept emails from Postmark:
+  #
+  #        # config/environments/production.rb
+  #        config.action_mailbox.ingress = :postmark
+  #
+  # 2. Generate a strong password that Action Mailbox can use to authenticate requests to the Postmark ingress.
+  #
+  #    Use <tt>rails credentials:edit</tt> to add the password to your application's encrypted credentials under
+  #    +action_mailbox.ingress_password+, where Action Mailbox will automatically find it:
+  #
+  #        action_mailbox:
+  #          ingress_password: ...
+  #
+  #    Alternatively, provide the password in the +RAILS_INBOUND_EMAIL_PASSWORD+ environment variable.
+  #
+  # 3. {Configure Postmark inbound webhook}[https://postmarkapp.com/manual#configure-your-inbound-webhook-url]
+  #    to forward inbound emails to +/rails/action_mailbox/postmark/inbound_emails+ with the username +actionmailbox+ and
+  #    the password you previously generated. If your application lived at <tt>https://example.com</tt>, you would
+  #    configure Postmark with the following fully-qualified URL:
+  #
+  #        https://actionmailbox:PASSWORD@example.com/rails/action_mailbox/postmark/inbound_emails
+  #
+  #    *NOTE:* When configuring your Postmark inbound webhook, be sure to check the box labeled *"Include raw email
+  #    content in JSON payload"*. Action Mailbox needs the raw email content to work.
+  class Ingresses::Postmark::InboundEmailsController < ActionMailbox::BaseController
+    before_action :authenticate_by_password
+
+    def create
+      ActionMailbox::InboundEmail.create_and_extract_message_id! params.require("RawEmail")
+    rescue ActionController::ParameterMissing => error
+      logger.error <<~MESSAGE
+        #{error.message}
+
+        When configuring your Postmark inbound webhook, be sure to check the box
+        labeled "Include raw email content in JSON payload".
+      MESSAGE
+      head :unprocessable_entity
+    end
+  end
+end
diff --git a/actionmailbox/config/routes.rb b/actionmailbox/config/routes.rb
index f1bc9847f5..7aa230fdff 100644
--- a/actionmailbox/config/routes.rb
+++ b/actionmailbox/config/routes.rb
@@ -5,6 +5,7 @@ Rails.application.routes.draw do
     post "/amazon/inbound_emails"   => "amazon/inbound_emails#create",   as: :rails_amazon_inbound_emails
     post "/mandrill/inbound_emails" => "mandrill/inbound_emails#create", as: :rails_mandrill_inbound_emails
     post "/postfix/inbound_emails"  => "postfix/inbound_emails#create",  as: :rails_postfix_inbound_emails
+    post "/postmark/inbound_emails" => "postmark/inbound_emails#create", as: :rails_postmark_inbound_emails
     post "/sendgrid/inbound_emails" => "sendgrid/inbound_emails#create", as: :rails_sendgrid_inbound_emails
 
     # Mailgun requires that a webhook's URL end in 'mime' for it to receive the raw contents of emails.
diff --git a/actionmailbox/test/controllers/ingresses/postmark/inbound_emails_controller_test.rb b/actionmailbox/test/controllers/ingresses/postmark/inbound_emails_controller_test.rb
new file mode 100644
index 0000000000..11b579b39c
--- /dev/null
+++ b/actionmailbox/test/controllers/ingresses/postmark/inbound_emails_controller_test.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class ActionMailbox::Ingresses::Postmark::InboundEmailsControllerTest < ActionDispatch::IntegrationTest
+  setup { ActionMailbox.ingress = :postmark }
+
+  test "receiving an inbound email from Postmark" do
+    assert_difference -> { ActionMailbox::InboundEmail.count }, +1 do
+      post rails_postmark_inbound_emails_url,
+        headers: { authorization: credentials }, params: { RawEmail: file_fixture("../files/welcome.eml").read }
+    end
+
+    assert_response :no_content
+
+    inbound_email = ActionMailbox::InboundEmail.last
+    assert_equal file_fixture("../files/welcome.eml").read, inbound_email.raw_email.download
+    assert_equal "0CB459E0-0336-41DA-BC88-E6E28C697DDB@37signals.com", inbound_email.message_id
+  end
+
+  test "rejecting when RawEmail param is missing" do
+    assert_no_difference -> { ActionMailbox::InboundEmail.count } do
+      post rails_postmark_inbound_emails_url,
+        headers: { authorization: credentials }, params: { From: "someone@example.com" }
+    end
+
+    assert_response :unprocessable_entity
+  end
+
+  test "rejecting an unauthorized inbound email from Postmark" do
+    assert_no_difference -> { ActionMailbox::InboundEmail.count } do
+      post rails_postmark_inbound_emails_url, params: { RawEmail: file_fixture("../files/welcome.eml").read }
+    end
+
+    assert_response :unauthorized
+  end
+
+  test "raising when the configured password is nil" do
+    switch_password_to nil do
+      assert_raises ArgumentError do
+        post rails_postmark_inbound_emails_url,
+          headers: { authorization: credentials }, params: { RawEmail: file_fixture("../files/welcome.eml").read }
+      end
+    end
+  end
+
+  test "raising when the configured password is blank" do
+    switch_password_to "" do
+      assert_raises ArgumentError do
+        post rails_postmark_inbound_emails_url,
+          headers: { authorization: credentials }, params: { RawEmail: file_fixture("../files/welcome.eml").read }
+      end
+    end
+  end
+end
diff --git a/guides/source/action_mailbox_basics.md b/guides/source/action_mailbox_basics.md
index eb8a14b4d2..f2c8a0a6b7 100644
--- a/guides/source/action_mailbox_basics.md
+++ b/guides/source/action_mailbox_basics.md
@@ -155,6 +155,42 @@ would look like this:
 $ URL=https://example.com/rails/action_mailbox/postfix/inbound_emails INGRESS_PASSWORD=... rails action_mailbox:ingress:postfix
 ```
 
+### Postmark
+
+Tell Action Mailbox to accept emails from Postmark:
+
+```ruby
+# config/environments/production.rb
+config.action_mailbox.ingress = :postmark
+```
+
+Generate a strong password that Action Mailbox can use to authenticate
+requests to the Postmark ingress.
+
+Use `rails credentials:edit` to add the password to your application's
+encrypted credentials under `action_mailbox.ingress_password`,
+where Action Mailbox will automatically find it:
+
+```yaml
+action_mailbox:
+  ingress_password: ...
+```
+
+Alternatively, provide the password in the `RAILS_INBOUND_EMAIL_PASSWORD`
+environment variable.
+
+[Configure Postmark inbound webhook](https://postmarkapp.com/manual#configure-your-inbound-webhook-url)
+to forward inbound emails to `/rails/action_mailbox/postmark/inbound_emails` with the username `actionmailbox`
+and the password you previously generated. If your application lived at `https://example.com`, you would
+configure Postmark with the following fully-qualified URL:
+
+```
+https://actionmailbox:PASSWORD@example.com/rails/action_mailbox/postmark/inbound_emails
+```
+
+NOTE: When configuring your Postmark inbound webhook, be sure to check the box labeled **"Include raw email content in JSON payload"**.
+Action Mailbox needs the raw email content to work.
+
 ### SendGrid
 
 Tell Action Mailbox to accept emails from SendGrid:
diff --git a/railties/test/application/rake/routes_test.rb b/railties/test/application/rake/routes_test.rb
index 933c735078..bbcda7c258 100644
--- a/railties/test/application/rake/routes_test.rb
+++ b/railties/test/application/rake/routes_test.rb
@@ -23,6 +23,7 @@ module ApplicationTests
                     rails_amazon_inbound_emails POST   /rails/action_mailbox/amazon/inbound_emails(.:format)                                    action_mailbox/ingresses/amazon/inbound_emails#create
                   rails_mandrill_inbound_emails POST   /rails/action_mailbox/mandrill/inbound_emails(.:format)                                  action_mailbox/ingresses/mandrill/inbound_emails#create
                    rails_postfix_inbound_emails POST   /rails/action_mailbox/postfix/inbound_emails(.:format)                                   action_mailbox/ingresses/postfix/inbound_emails#create
+                  rails_postmark_inbound_emails POST   /rails/action_mailbox/postmark/inbound_emails(.:format)                                  action_mailbox/ingresses/postmark/inbound_emails#create
                   rails_sendgrid_inbound_emails POST   /rails/action_mailbox/sendgrid/inbound_emails(.:format)                                  action_mailbox/ingresses/sendgrid/inbound_emails#create
                    rails_mailgun_inbound_emails POST   /rails/action_mailbox/mailgun/inbound_emails/mime(.:format)                              action_mailbox/ingresses/mailgun/inbound_emails#create
                  rails_conductor_inbound_emails GET    /rails/conductor/action_mailbox/inbound_emails(.:format)                                 rails/conductor/action_mailbox/inbound_emails#index
diff --git a/railties/test/commands/routes_test.rb b/railties/test/commands/routes_test.rb
index a43a6d32b9..f77214ac2a 100644
--- a/railties/test/commands/routes_test.rb
+++ b/railties/test/commands/routes_test.rb
@@ -18,15 +18,16 @@ class Rails::Command::RoutesTest < ActiveSupport::TestCase
     RUBY
 
     assert_equal <<~OUTPUT, run_routes_command([ "-c", "PostController" ])
-                            Prefix Verb   URI Pattern                                            Controller#Action
-                          new_post GET    /post/new(.:format)                                    posts#new
-                         edit_post GET    /post/edit(.:format)                                   posts#edit
-                              post GET    /post(.:format)                                        posts#show
-                                   PATCH  /post(.:format)                                        posts#update
-                                   PUT    /post(.:format)                                        posts#update
-                                   DELETE /post(.:format)                                        posts#destroy
-                                   POST   /post(.:format)                                        posts#create
-      rails_postfix_inbound_emails POST   /rails/action_mailbox/postfix/inbound_emails(.:format) action_mailbox/ingresses/postfix/inbound_emails#create
+                             Prefix Verb   URI Pattern                                             Controller#Action
+                           new_post GET    /post/new(.:format)                                     posts#new
+                          edit_post GET    /post/edit(.:format)                                    posts#edit
+                               post GET    /post(.:format)                                         posts#show
+                                    PATCH  /post(.:format)                                         posts#update
+                                    PUT    /post(.:format)                                         posts#update
+                                    DELETE /post(.:format)                                         posts#destroy
+                                    POST   /post(.:format)                                         posts#create
+       rails_postfix_inbound_emails POST   /rails/action_mailbox/postfix/inbound_emails(.:format)  action_mailbox/ingresses/postfix/inbound_emails#create
+      rails_postmark_inbound_emails POST   /rails/action_mailbox/postmark/inbound_emails(.:format) action_mailbox/ingresses/postmark/inbound_emails#create
     OUTPUT
 
     assert_equal <<~OUTPUT, run_routes_command([ "-c", "UserPermissionController" ])
@@ -65,6 +66,7 @@ class Rails::Command::RoutesTest < ActiveSupport::TestCase
                 rails_amazon_inbound_emails POST /rails/action_mailbox/amazon/inbound_emails(.:format)               action_mailbox/ingresses/amazon/inbound_emails#create
               rails_mandrill_inbound_emails POST /rails/action_mailbox/mandrill/inbound_emails(.:format)             action_mailbox/ingresses/mandrill/inbound_emails#create
                rails_postfix_inbound_emails POST /rails/action_mailbox/postfix/inbound_emails(.:format)              action_mailbox/ingresses/postfix/inbound_emails#create
+              rails_postmark_inbound_emails POST /rails/action_mailbox/postmark/inbound_emails(.:format)             action_mailbox/ingresses/postmark/inbound_emails#create
               rails_sendgrid_inbound_emails POST /rails/action_mailbox/sendgrid/inbound_emails(.:format)             action_mailbox/ingresses/sendgrid/inbound_emails#create
                rails_mailgun_inbound_emails POST /rails/action_mailbox/mailgun/inbound_emails/mime(.:format)         action_mailbox/ingresses/mailgun/inbound_emails#create
                                             POST /rails/conductor/action_mailbox/inbound_emails(.:format)            rails/conductor/action_mailbox/inbound_emails#create
@@ -131,15 +133,16 @@ class Rails::Command::RoutesTest < ActiveSupport::TestCase
     OUTPUT
 
     assert_equal <<~OUTPUT, run_routes_command([ "-c", "PostController" ])
-                            Prefix Verb   URI Pattern                                            Controller#Action
-                    new_admin_post GET    /admin/post/new(.:format)                              admin/posts#new
-                   edit_admin_post GET    /admin/post/edit(.:format)                             admin/posts#edit
-                        admin_post GET    /admin/post(.:format)                                  admin/posts#show
-                                   PATCH  /admin/post(.:format)                                  admin/posts#update
-                                   PUT    /admin/post(.:format)                                  admin/posts#update
-                                   DELETE /admin/post(.:format)                                  admin/posts#destroy
-                                   POST   /admin/post(.:format)                                  admin/posts#create
-      rails_postfix_inbound_emails POST   /rails/action_mailbox/postfix/inbound_emails(.:format) action_mailbox/ingresses/postfix/inbound_emails#create
+                             Prefix Verb   URI Pattern                                             Controller#Action
+                     new_admin_post GET    /admin/post/new(.:format)                               admin/posts#new
+                    edit_admin_post GET    /admin/post/edit(.:format)                              admin/posts#edit
+                         admin_post GET    /admin/post(.:format)                                   admin/posts#show
+                                    PATCH  /admin/post(.:format)                                   admin/posts#update
+                                    PUT    /admin/post(.:format)                                   admin/posts#update
+                                    DELETE /admin/post(.:format)                                   admin/posts#destroy
+                                    POST   /admin/post(.:format)                                   admin/posts#create
+       rails_postfix_inbound_emails POST   /rails/action_mailbox/postfix/inbound_emails(.:format)  action_mailbox/ingresses/postfix/inbound_emails#create
+      rails_postmark_inbound_emails POST   /rails/action_mailbox/postmark/inbound_emails(.:format) action_mailbox/ingresses/postmark/inbound_emails#create
     OUTPUT
 
     expected_permission_output = <<~OUTPUT
@@ -168,6 +171,7 @@ class Rails::Command::RoutesTest < ActiveSupport::TestCase
                 rails_amazon_inbound_emails POST   /rails/action_mailbox/amazon/inbound_emails(.:format)                                    action_mailbox/ingresses/amazon/inbound_emails#create
               rails_mandrill_inbound_emails POST   /rails/action_mailbox/mandrill/inbound_emails(.:format)                                  action_mailbox/ingresses/mandrill/inbound_emails#create
                rails_postfix_inbound_emails POST   /rails/action_mailbox/postfix/inbound_emails(.:format)                                   action_mailbox/ingresses/postfix/inbound_emails#create
+              rails_postmark_inbound_emails POST   /rails/action_mailbox/postmark/inbound_emails(.:format)                                  action_mailbox/ingresses/postmark/inbound_emails#create
               rails_sendgrid_inbound_emails POST   /rails/action_mailbox/sendgrid/inbound_emails(.:format)                                  action_mailbox/ingresses/sendgrid/inbound_emails#create
                rails_mailgun_inbound_emails POST   /rails/action_mailbox/mailgun/inbound_emails/mime(.:format)                              action_mailbox/ingresses/mailgun/inbound_emails#create
              rails_conductor_inbound_emails GET    /rails/conductor/action_mailbox/inbound_emails(.:format)                                 rails/conductor/action_mailbox/inbound_emails#index
@@ -220,81 +224,86 @@ class Rails::Command::RoutesTest < ActiveSupport::TestCase
       URI               | /rails/action_mailbox/postfix/inbound_emails(.:format)
       Controller#Action | action_mailbox/ingresses/postfix/inbound_emails#create
       --[ Route 5 ]--------------
+      Prefix            | rails_postmark_inbound_emails
+      Verb              | POST
+      URI               | /rails/action_mailbox/postmark/inbound_emails(.:format)
+      Controller#Action | action_mailbox/ingresses/postmark/inbound_emails#create
+      --[ Route 6 ]--------------
       Prefix            | rails_sendgrid_inbound_emails
       Verb              | POST
       URI               | /rails/action_mailbox/sendgrid/inbound_emails(.:format)
       Controller#Action | action_mailbox/ingresses/sendgrid/inbound_emails#create
-      --[ Route 6 ]--------------
+      --[ Route 7 ]--------------
       Prefix            | rails_mailgun_inbound_emails
       Verb              | POST
       URI               | /rails/action_mailbox/mailgun/inbound_emails/mime(.:format)
       Controller#Action | action_mailbox/ingresses/mailgun/inbound_emails#create
-      --[ Route 7 ]--------------
+      --[ Route 8 ]--------------
       Prefix            | rails_conductor_inbound_emails
       Verb              | GET
       URI               | /rails/conductor/action_mailbox/inbound_emails(.:format)
       Controller#Action | rails/conductor/action_mailbox/inbound_emails#index
-      --[ Route 8 ]--------------
+      --[ Route 9 ]--------------
       Prefix            | 
       Verb              | POST
       URI               | /rails/conductor/action_mailbox/inbound_emails(.:format)
       Controller#Action | rails/conductor/action_mailbox/inbound_emails#create
-      --[ Route 9 ]--------------
+      --[ Route 10 ]-------------
       Prefix            | new_rails_conductor_inbound_email
       Verb              | GET
       URI               | /rails/conductor/action_mailbox/inbound_emails/new(.:format)
       Controller#Action | rails/conductor/action_mailbox/inbound_emails#new
-      --[ Route 10 ]-------------
+      --[ Route 11 ]-------------
       Prefix            | edit_rails_conductor_inbound_email
       Verb              | GET
       URI               | /rails/conductor/action_mailbox/inbound_emails/:id/edit(.:format)
       Controller#Action | rails/conductor/action_mailbox/inbound_emails#edit
-      --[ Route 11 ]-------------
+      --[ Route 12 ]-------------
       Prefix            | rails_conductor_inbound_email
       Verb              | GET
       URI               | /rails/conductor/action_mailbox/inbound_emails/:id(.:format)
       Controller#Action | rails/conductor/action_mailbox/inbound_emails#show
-      --[ Route 12 ]-------------
+      --[ Route 13 ]-------------
       Prefix            | 
       Verb              | PATCH
       URI               | /rails/conductor/action_mailbox/inbound_emails/:id(.:format)
       Controller#Action | rails/conductor/action_mailbox/inbound_emails#update
-      --[ Route 13 ]-------------
+      --[ Route 14 ]-------------
       Prefix            | 
       Verb              | PUT
       URI               | /rails/conductor/action_mailbox/inbound_emails/:id(.:format)
       Controller#Action | rails/conductor/action_mailbox/inbound_emails#update
-      --[ Route 14 ]-------------
+      --[ Route 15 ]-------------
       Prefix            | 
       Verb              | DELETE
       URI               | /rails/conductor/action_mailbox/inbound_emails/:id(.:format)
       Controller#Action | rails/conductor/action_mailbox/inbound_emails#destroy
-      --[ Route 15 ]-------------
+      --[ Route 16 ]-------------
       Prefix            | rails_conductor_inbound_email_reroute
       Verb              | POST
       URI               | /rails/conductor/action_mailbox/:inbound_email_id/reroute(.:format)
       Controller#Action | rails/conductor/action_mailbox/reroutes#create
-      --[ Route 16 ]-------------
+      --[ Route 17 ]-------------
       Prefix            | rails_service_blob
       Verb              | GET
       URI               | /rails/active_storage/blobs/:signed_id/*filename(.:format)
       Controller#Action | active_storage/blobs#show
-      --[ Route 17 ]-------------
+      --[ Route 18 ]-------------
       Prefix            | rails_blob_representation
       Verb              | GET
       URI               | /rails/active_storage/representations/:signed_blob_id/:variation_key/*filename(.:format)
       Controller#Action | active_storage/representations#show
-      --[ Route 18 ]-------------
+      --[ Route 19 ]-------------
       Prefix            | rails_disk_service
       Verb              | GET
       URI               | /rails/active_storage/disk/:encoded_key/*filename(.:format)
       Controller#Action | active_storage/disk#show
-      --[ Route 19 ]-------------
+      --[ Route 20 ]-------------
       Prefix            | update_rails_disk_service
       Verb              | PUT
       URI               | /rails/active_storage/disk/:encoded_token(.:format)
       Controller#Action | active_storage/disk#update
-      --[ Route 20 ]-------------
+      --[ Route 21 ]-------------
       Prefix            | rails_direct_uploads
       Verb              | POST
       URI               | /rails/active_storage/direct_uploads(.:format)