feat: add instrumentation support for action mailer

instrumentation/action_mailer/.rubocop.yml

@@ -0,0 +1 @@
+inherit_from: ../../.rubocop.yml

instrumentation/action_mailer/.yardopts

@@ -0,0 +1,9 @@
+--no-private
+--title=OpenTelemetry Action Mailer Instrumentation
+--markup=markdown
+--main=README.md
+./lib/opentelemetry/instrumentation/**/*.rb
+./lib/opentelemetry/instrumentation.rb
+-
+README.md
+CHANGELOG.md

instrumentation/action_mailer/Appraisals

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+appraise 'rails-6.1' do
+  gem 'rails', '~> 6.1.0'
+end
+
+appraise 'rails-7.0' do
+  gem 'rails', '~> 7.0.0'
+end
+
+appraise 'rails-7.1' do
+  gem 'rails', '~> 7.1.0'
+end

instrumentation/action_mailer/CHANGELOG.md

@@ -0,0 +1,5 @@
+# Release History: opentelemetry-instrumentation-action_mailer
+
+### v0.1.0 / 2024-02-22
+
+* Initial release.

instrumentation/action_mailer/Gemfile

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+source 'https://rubygems.org'
+
+gemspec
+
+group :test do
+  gem 'opentelemetry-instrumentation-base', path: '../base'
+  gem 'opentelemetry-instrumentation-active_support', path: '../active_support'
+  gem 'pry-byebug'
+end

instrumentation/action_mailer/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright The OpenTelemetry Authors
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

instrumentation/action_mailer/README.md

@@ -0,0 +1,100 @@
+# OpenTelemetry ActionMailer Instrumentation
+
+The ActionMailer instrumentation is a community-maintained instrumentation for the ActionMailer portion of the [Ruby on Rails][rails-home] web-application framework.
+
+## How do I get started?
+
+Install the gem using:
+
+```
+gem install opentelemetry-instrumentation-action_mailer
+gem install opentelemetry-instrumentation-rails
+```
+
+Or, if you use [bundler][bundler-home], include `opentelemetry-instrumentation-action_mailer` in your `Gemfile`.
+
+## Usage
+
+To use the instrumentation, call `use` with the name of the instrumentation:
+
+```ruby
+OpenTelemetry::SDK.configure do |c|
+  c.use 'OpenTelemetry::Instrumentation::Rails'
+  c.use 'OpenTelemetry::Instrumentation::ActionMailer'
+end
+```
+
+Alternatively, you can also call `use_all` to install all the available instrumentation.
+
+```ruby
+OpenTelemetry::SDK.configure do |c|
+  c.use_all
+end
+```
+
+### Options
+
+ActionMailer instrumentation doesn't expose email address by default, but if email address is needed, simply use `:email_address` option:
+```ruby
+OpenTelemetry::SDK.configure do |c|
+  c.use 'OpenTelemetry::Instrumentation::ActionMailer', { email_address: :include }
+end
+```
+
+If only want to hide certain field for email address:
+```ruby
+OpenTelemetry::SDK.configure do |c|
+  c.use 'OpenTelemetry::Instrumentation::ActionMailer', { email_address: :include, disallowed_notification_payload_keys: ['email.to.address'] }
+end
+```
+
+
+## Active Support Instrumentation
+
+This instrumentation now relies entirely on `ActiveSupport::Notifications` and registers a custom Subscriber that listens to relevant events to report as spans.
+
+See the table below for details of what [Rails Framework Hook Events](https://guides.rubyonrails.org/active_support_instrumentation.html#action-mailer) are recorded by this instrumentation:
+
+| Event Name | Creates Span? | Notes |
+| - | - | - |
+| `deliver.action_mailer` | :white_check_mark: | Creates an span with kind `internal` and email content and status|
+| `process.action_mailer` | :x: | Lack of useful info so ignored |
+
+## Semantic Conventions
+
+Internal spans are named using the name of the `ActiveSupport` event that was provided (e.g. `action_mailer deliver`).
+
+Attributes that are specific to this instrumentation are recorded under `action_mailer deliver`:
+
+| Attribute Name | Type | Notes |
+| - | - | - |
+| `email.x_mailer` | String | Mailer class that is used to send mail |
+| `email.message_id` | String | Set from Mail gem|
+| `email.subject` | String | Mail subject |
+| `email.to.address` | Array | Receiver for mails (omit by default, inlcude when `email_address` set to `:include`) |
+| `email.from.address` | Array | Sender for mails (omit by default, inlcude when `email_address` set to `:include`) |
+| `email.cc.address` | Array | mails CC (omit by default, inlcude when `email_address` set to `:include`) |
+| `email.bcc.address` | Array | mails BCC (omit by default, inlcude when `email_address` set to `:include`)  |
+
+## Examples
+
+Example usage can be seen in the `./example/trace_request_demonstration.ru` file [here](https://github.com/open-telemetry/opentelemetry-ruby-contrib/blob/main/instrumentation/action_mailer/example/trace_request_demonstration.ru)
+
+
+## How can I get involved?
+
+The `opentelemetry-instrumentation-action_mailer` gem source is [on github][repo-github], along with related gems including `opentelemetry-api` and `opentelemetry-sdk`.
+
+The OpenTelemetry Ruby gems are maintained by the OpenTelemetry-Ruby special interest group (SIG). You can get involved by joining us in [GitHub Discussions][discussions-url] or attending our weekly meeting. See the [meeting calendar][community-meetings] for dates and times. For more information on this and other language SIGs, see the OpenTelemetry [community page][ruby-sig].
+
+## License
+
+The `opentelemetry-instrumentation-action_mailer` gem is distributed under the Apache 2.0 license. See [LICENSE][license-github] for more information.
+
+[rails-home]: https://github.com/rails/rails
+[bundler-home]: https://bundler.io
+[repo-github]: https://github.com/open-telemetry/opentelemetry-ruby
+[license-github]: https://github.com/open-telemetry/opentelemetry-ruby-contrib/blob/main/LICENSE
+[ruby-sig]: https://github.com/open-telemetry/community#ruby-sig
+[community-meetings]: https://github.com/open-telemetry/community#community-meetings
+[discussions-url]: https://github.com/open-telemetry/opentelemetry-ruby/discussions

instrumentation/action_mailer/Rakefile

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+require 'bundler/gem_tasks'
+require 'rake/testtask'
+require 'yard'
+require 'rubocop/rake_task'
+
+RuboCop::RakeTask.new
+
+Rake::TestTask.new :test do |t|
+  t.libs << 'test'
+  t.libs << 'lib'
+  t.test_files = FileList['test/**/*_test.rb']
+end
+
+YARD::Rake::YardocTask.new do |t|
+  t.stats_options = ['--list-undoc']
+end
+
+if RUBY_ENGINE == 'truffleruby'
+  task default: %i[test]
+else
+  task default: %i[test rubocop yard]
+end

instrumentation/action_mailer/example/app/views/test_mailer/welcome_email.html.erb

@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>Welcome to OpenTelemetry!</title>
+</head>
+<body>
+  <h1>Welcome!</h1>
+  <p>Thank you for joining OpenTelemetry.</p>
+</body>
+</html>

instrumentation/action_mailer/example/tmp/local_secret.txt

@@ -0,0 +1 @@
+11007269270afc9d0da1bf5aebb7b00264473f1f36b82208c8f0d4375f516e03f41d91e2f81c1f6482b95540b07a7c4444d8cf329e8337dd397b14a59dd14a0e