[PROF-11827] Enable publishing ruby gem from CI using trusted publishing (#1070)

* Fix bundler not working in rubygems/release-gem

The `rubygems/release-gem` step was failing with:

```
Run bundle exec rake release
Could not locate Gemfile or .bundle/ directory
```

...because it runs that command from the root of the repository, not the
 `ruby/` folder.

It seems a bit harder to specify the folder, so instead I'm adding a
bundler config file to tell bundler (the `bundle` command) where
to find what it needs.

* Move all files needed to release Ruby to a single folder

This way we don't need to litter the repository with random files
outside the Ruby folder.

* Enable publish step, now that the rest of the workflow is working fine

* Add logging to push step

* Simplify Ruby publish steps even further

This also fixes ruby/setup-ruby caching!

* Use `eval_gemfile` instead of copying Gemfile to root

(Because the `gems.rb` uses `gemspec` and this failed because it
wouldn't find the `gemspec` when run from the root of the repo)

* Tweak test name

Author: ivoanjo

.github/workflows/publish-ruby.yml

@@ -12,11 +12,16 @@ jobs:
       id-token: write # Required for trusted publishing, see https://github.com/rubygems/release-gem
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: Set up publish environment # This is needed to allow the following steps to run from the root of the repository
+        run: |
+          echo 'eval_gemfile("ruby/gems.rb")' > Gemfile
+          cp ruby/publish/rakefile.rb .
+          ln -sf ruby/pkg/ pkg
       - name: Set up Ruby
         uses: ruby/setup-ruby@e34163cd15f4bb403dcd72d98e295997e6a55798 # v1.238.0
         with:
           ruby-version: 'ruby'
+          bundler-cache: true
       - name: Install dependencies
-        working-directory: ruby
         run: bundle install
       - uses: rubygems/release-gem@a25424ba2ba8b387abc8ef40807c2c85b96cbe32 # v1.1.1

ruby/Rakefile

@@ -129,10 +129,14 @@ task push_to_rubygems: [
   :package,
   :"release:guard_clean"
 ] do
-  puts "TODO: DISABLED PUSHING TO RUBYGEMS"
-  # abort unless system("gem push pkg/libdatadog-#{Libdatadog::VERSION}.gem")
-  # abort unless system("gem push pkg/libdatadog-#{Libdatadog::VERSION}-x86_64-linux.gem")
-  # abort unless system("gem push pkg/libdatadog-#{Libdatadog::VERSION}-aarch64-linux.gem")
+  [
+    "gem push pkg/libdatadog-#{Libdatadog::VERSION}.gem",
+    "gem push pkg/libdatadog-#{Libdatadog::VERSION}-x86_64-linux.gem",
+    "gem push pkg/libdatadog-#{Libdatadog::VERSION}-aarch64-linux.gem"
+  ].each do |command|
+    puts "Running: #{command}"
+    abort unless system(command)
+  end
 end
 
 module Helpers

ruby/gems.rb

@@ -2,7 +2,6 @@
 
 source "https://rubygems.org"
 
-# Specify your gem's dependencies in libdatadog.gemspec
 gemspec
 
 gem "rake", ">= 12.0", "< 14"

ruby/libdatadog.gemspec

@@ -31,7 +31,7 @@ Gem::Specification.new do |spec|
     `git ls-files -z`
       .split("\x0")
       .reject do |f|
-        (f == __FILE__) || f.match(%r{\A(?:(?:bin|test|spec|features)/|\.(?:git|travis|circleci)|appveyor)})
+        (f == __FILE__) || f.match(%r{\A(?:(?:bin|test|spec|features|publish)/|\.(?:git|travis|circleci)|appveyor)})
       end
       .reject do |f|
         [".rspec", ".standard.yml", "Rakefile", "docker-compose.yml", "gems.rb", "README.md"].include?(f)

rakefile.rb renamed to ruby/publish/rakefile.rb

@@ -11,7 +11,7 @@
   let(:packaged_gem_file) { "pkg/libdatadog-#{gem_version}.gem" }
   let(:executable_permissions) { ["libdatadog-crashtracking-receiver", "libdatadog_profiling.so"] }
 
-  it "sets the right permissions on the gem files" do
+  it "sets the right permissions on the .gem files" do
     gem_files = Dir.glob("pkg/*.gem")
     expect(gem_files).to include(packaged_gem_file)