RC: Add process tags to remote configuration payloads

lib/datadog/core/environment/process.rb

@@ -14,6 +14,14 @@ module Process
         # @return [String] comma-separated normalized key:value pairs
         def self.serialized
           return @serialized if defined?(@serialized)
+
+          @serialized = tags_array.join(',').freeze
+        end
+
+        # This method returns an array in the format ["k1:v1","k2:v2","k3:v3"]
+        # @return [Array<String>] array of normalized key:value pairs
+        def self.tags_array
+          return @tags_array if defined?(@tags_array)
           tags = []
 
           workdir = TagNormalizer.normalize_process_value(entrypoint_workdir.to_s)
@@ -27,7 +35,7 @@ def self.serialized
 
           tags << "#{Environment::Ext::TAG_ENTRYPOINT_TYPE}:#{TagNormalizer.normalize(entrypoint_type, remove_digit_start_char: false)}"
 
-          @serialized = tags.join(',').freeze
+          @tags_array = tags.freeze
         end
 
         # Returns the last segment of the working directory of the process

lib/datadog/core/remote/client.rb

@@ -161,6 +161,11 @@ def payload # standard:disable Metrics/MethodLength
 
           client_tracer[:app_version] = app_version if app_version
 
+          if Datadog.configuration.experimental_propagate_process_tags_enabled
+            process_tags = Core::Environment::Process.tags_array
+            client_tracer[:process_tags] = process_tags if process_tags.any?
+          end
+
           {
             client: {
               state: {

sig/datadog/core/environment/process.rbs

@@ -3,9 +3,12 @@ module Datadog
     module Environment
       module Process
         @serialized: ::String
+        @tags_array: Array[::String]
 
         def self.serialized: () -> ::String
 
+        def self.tags_array: () -> ::Array[::String]
+
         private
 
         def self.entrypoint_workdir: () -> ::String

spec/datadog/core/environment/process_spec.rb

@@ -3,13 +3,14 @@
 require 'open3'
 
 RSpec.describe Datadog::Core::Environment::Process do
+  def reset_memoized_variables!
+    described_class.remove_instance_variable(:@serialized) if described_class.instance_variable_defined?(:@serialized)
+    described_class.remove_instance_variable(:@tags_array) if described_class.instance_variable_defined?(:@tags_array)
+  end
+
   describe '::serialized' do
     subject(:serialized) { described_class.serialized }
 
-    def reset_serialized!
-      described_class.remove_instance_variable(:@serialized) if described_class.instance_variable_defined?(:@serialized)
-    end
-
     shared_context 'with mocked process environment' do
       let(:pwd) { '/app' }
 
@@ -24,11 +25,11 @@ def reset_serialized!
         allow(Dir).to receive(:pwd).and_return(pwd)
         allow(File).to receive(:expand_path).and_call_original
         allow(File).to receive(:expand_path).with('.').and_return('/app')
-        reset_serialized!
+        reset_memoized_variables!
       end
 
       after do
-        reset_serialized!
+        reset_memoized_variables!
       end
     end
 
@@ -147,4 +148,107 @@ def reset_serialized!
       end
     end
   end
+  describe '::tags_array' do
+    subject(:tags_array) { described_class.tags_array }
+
+    shared_context 'with mocked process environment' do
+      let(:pwd) { '/app' }
+
+      around do |example|
+        @original_0 = $0
+        $0 = program_name
+        example.run
+        $0 = @original_0
+      end
+
+      before do
+        allow(Dir).to receive(:pwd).and_return(pwd)
+        allow(File).to receive(:expand_path).and_call_original
+        allow(File).to receive(:expand_path).with('.').and_return('/app')
+        reset_memoized_variables!
+      end
+
+      after do
+        reset_memoized_variables!
+      end
+    end
+
+    it { is_expected.to be_a_kind_of(Array) }
+
+    it 'is an array of strings' do
+      expect(tags_array).to all(be_a(String))
+    end
+
+    it 'returns the same object when called multiple times' do
+      # Processes are fixed so no need to recompute this on each call
+      first_call = described_class.tags_array
+      second_call = described_class.tags_array
+      expect(first_call).to equal(second_call)
+    end
+
+    context 'with /expectedbasedir/executable' do
+      include_context 'with mocked process environment'
+      let(:program_name) { '/expectedbasedir/executable' }
+
+      it 'extracts out the tag array correctly' do
+        expect(tags_array.length).to eq(4)
+        expect(described_class.tags_array).to include('entrypoint.workdir:app')
+        expect(described_class.tags_array).to include('entrypoint.name:executable')
+        expect(described_class.tags_array).to include('entrypoint.basedir:expectedbasedir')
+        expect(described_class.tags_array).to include('entrypoint.type:script')
+      end
+    end
+
+    context 'with irb' do
+      include_context 'with mocked process environment'
+      let(:program_name) { 'irb' }
+
+      it 'extracts out the tag array correctly' do
+        expect(tags_array.length).to eq(4)
+        expect(described_class.tags_array).to include('entrypoint.workdir:app')
+        expect(described_class.tags_array).to include('entrypoint.name:irb')
+        expect(described_class.tags_array).to include('entrypoint.basedir:app')
+        expect(described_class.tags_array).to include('entrypoint.type:script')
+      end
+    end
+
+    context 'with my/path/rubyapp.rb' do
+      include_context 'with mocked process environment'
+      let(:program_name) { 'my/path/rubyapp.rb' }
+
+      it 'extracts out the tag array correctly' do
+        expect(tags_array.length).to eq(4)
+        expect(described_class.tags_array).to include('entrypoint.workdir:app')
+        expect(described_class.tags_array).to include('entrypoint.name:rubyapp.rb')
+        expect(described_class.tags_array).to include('entrypoint.basedir:path')
+        expect(described_class.tags_array).to include('entrypoint.type:script')
+      end
+    end
+
+    context 'with my/path/foo:,bar' do
+      include_context 'with mocked process environment'
+      let(:program_name) { 'my/path/foo:,bar' }
+
+      it 'extracts out the tag array correctly' do
+        expect(tags_array.length).to eq(4)
+        expect(described_class.tags_array).to include('entrypoint.workdir:app')
+        expect(described_class.tags_array).to include('entrypoint.name:foo_bar')
+        expect(described_class.tags_array).to include('entrypoint.basedir:path')
+        expect(described_class.tags_array).to include('entrypoint.type:script')
+      end
+    end
+
+    context 'with bin/rails' do
+      include_context 'with mocked process environment'
+      let(:program_name) { 'bin/rails' }
+
+      it 'extracts out the tags array correctly' do
+        expect(tags_array.length).to eq(4)
+        expect(described_class.tags_array).to include('entrypoint.workdir:app')
+        expect(described_class.tags_array).to include('entrypoint.name:rails')
+        expect(described_class.tags_array).to include('entrypoint.basedir:bin')
+        expect(described_class.tags_array).to include('entrypoint.type:script')
+      end
+    end
+  end
 end

spec/datadog/core/remote/client_spec.rb

@@ -677,6 +677,41 @@
           end
         end
 
+        context 'process_tags' do
+          let(:client_payload) { client.send(:payload)[:client] }
+
+          context 'when process tags propagation is enabled' do
+            before do
+              allow(Datadog.configuration).to receive(:experimental_propagate_process_tags_enabled).and_return(true)
+              if Datadog::Core::Environment::Process.instance_variable_defined?(:@tags_array)
+                Datadog::Core::Environment::Process.remove_instance_variable(:@tags_array)
+              end
+            end
+
+            it 'has process tags in the payload' do
+              process_tags = client_payload[:client_tracer][:process_tags]
+              expect(process_tags).to be_a(Array)
+              expect(process_tags).to include('entrypoint.workdir:app')
+              expect(process_tags).to include('entrypoint.name:rspec')
+              expect(process_tags).to include('entrypoint.basedir:bin')
+              expect(process_tags).to include('entrypoint.type:script')
+            end
+          end
+
+          context 'when process tags propagation is not enabled' do
+            # Current false by default
+            before do
+              if Datadog::Core::Environment::Process.instance_variable_defined?(:@tags_array)
+                Datadog::Core::Environment::Process.remove_instance_variable(:@tags_array)
+              end
+            end
+
+            it 'does not have process tags in the payload' do
+              expect(client_payload[:client_tracer]).not_to have_key(:process_tags)
+            end
+          end
+        end
+
         context 'cached_target_files' do
           it 'returns cached_target_files' do
             state = repository.state