Track usage for Terraform State API

changelogs/unreleased/add-terraform-state-api-usage-tracking.yml

+---
+title: Track usage for Terraform State API
+merge_request: 50224
+author:
+type: added

config/feature_flags/development/usage_data_p_terraform_state_api_unique_users.yml

+---
+name: usage_data_p_terraform_state_api_unique_users
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/50224
+rollout_issue_url:
+milestone: '13.8'
+type: development
+group: group::configure
+default_enabled: true

lib/api/terraform/state.rb

@@ -14,6 +14,8 @@ module API
       before do
         authenticate!
         authorize! :read_terraform_state, user_project
+
+        increment_unique_values('p_terraform_state_api_unique_users', current_user.id)
       end
 
       params do

lib/gitlab/usage_data_counters/hll_redis_counter.rb

@@ -123,7 +123,7 @@ module Gitlab
           Gitlab::Redis::HLL.add(key: redis_key(event, time, context), value: value, expiry: expiry(event))
         end
 
-        # The aray of valid context on which we allow tracking
+        # The array of valid context on which we allow tracking
         def valid_context_list
           Plan.all_plans
         end

lib/gitlab/usage_data_counters/known_events/common.yml

@@ -440,3 +440,9 @@
   category: code_review
   aggregation: weekly
   feature_flag: usage_data_i_code_review_mr_single_file_diffs
+# Terraform
+- name: p_terraform_state_api_unique_users
+  category: terraform
+  redis_slot: terraform
+  aggregation: weekly
+  feature_flag: usage_data_p_terraform_state_api_unique_users

spec/lib/gitlab/usage_data_counters/hll_redis_counter_spec.rb

@@ -46,7 +46,8 @@ RSpec.describe Gitlab::UsageDataCounters::HLLRedisCounter, :clean_gitlab_redis_s
         'container_packages',
         'tag_packages',
         'snippets',
-        'code_review'
+        'code_review',
+        'terraform'
       )
     end
   end

spec/lib/gitlab/usage_data_spec.rb

@@ -1260,7 +1260,7 @@ RSpec.describe Gitlab::UsageData, :aggregate_failures do
     subject { described_class.redis_hll_counters }
 
     let(:categories) { ::Gitlab::UsageDataCounters::HLLRedisCounter.categories }
-    let(:ineligible_total_categories) { %w[source_code testing ci_secrets_management incident_management_alerts snippets] }
+    let(:ineligible_total_categories) { %w[source_code testing ci_secrets_management incident_management_alerts snippets terraform] }
 
     it 'has all known_events' do
       expect(subject).to have_key(:redis_hll_counters)

spec/requests/api/terraform/state_spec.rb

@@ -21,9 +21,36 @@ RSpec.describe API::Terraform::State do
     stub_terraform_state_object_storage
   end
 
+  shared_examples 'endpoint with unique user tracking' do
+    context 'without authentication' do
+      let(:auth_header) { basic_auth_header('bad', 'token') }
+
+      before do
+        stub_feature_flags(usage_data_p_terraform_state_api_unique_users: false)
+      end
+
+      it 'does not track unique event' do
+        expect(Gitlab::UsageDataCounters::HLLRedisCounter).not_to receive(:track_event)
+
+        request
+      end
+    end
+
+    context 'with maintainer permissions' do
+      let(:current_user) { maintainer }
+
+      it_behaves_like 'tracking unique hll events', :usage_data_p_terraform_state_api_unique_users do
+        let(:target_id) { 'p_terraform_state_api_unique_users' }
+        let(:expected_type) { instance_of(Integer) }
+      end
+    end
+  end
+
   describe 'GET /projects/:id/terraform/state/:name' do
     subject(:request) { get api(state_path), headers: auth_header }
 
+    it_behaves_like 'endpoint with unique user tracking'
+
     context 'without authentication' do
       let(:auth_header) { basic_auth_header('bad', 'token') }
 
@@ -117,6 +144,8 @@ RSpec.describe API::Terraform::State do
 
     subject(:request) { post api(state_path), headers: auth_header, as: :json, params: params }
 
+    it_behaves_like 'endpoint with unique user tracking'
+
     context 'when terraform state with a given name is already present' do
       context 'with maintainer permissions' do
         let(:current_user) { maintainer }
@@ -219,6 +248,8 @@ RSpec.describe API::Terraform::State do
   describe 'DELETE /projects/:id/terraform/state/:name' do
     subject(:request) { delete api(state_path), headers: auth_header }
 
+    it_behaves_like 'endpoint with unique user tracking'
+
     context 'with maintainer permissions' do
       let(:current_user) { maintainer }
 
@@ -256,6 +287,8 @@ RSpec.describe API::Terraform::State do
 
     subject(:request) { post api("#{state_path}/lock"), headers: auth_header, params: params }
 
+    it_behaves_like 'endpoint with unique user tracking'
+
     it 'locks the terraform state' do
       request
 
@@ -305,6 +338,10 @@ RSpec.describe API::Terraform::State do
 
     subject(:request) { delete api("#{state_path}/lock"), headers: auth_header, params: params }
 
+    it_behaves_like 'endpoint with unique user tracking' do
+      let(:lock_id) { 'irrelevant to this test, just needs to be present' }
+    end
+
     context 'with the correct lock id' do
       let(:lock_id) { '123-456' }