Remove prometheus IAP feature flag

app/models/project_services/prometheus_service.rb

@@ -54,7 +54,7 @@ class PrometheusService < MonitoringService
   end
 
   def fields
-    result = [
+    [
       {
         type: 'checkbox',
         name: 'manual_configuration',
@@ -67,11 +67,7 @@ class PrometheusService < MonitoringService
         title: 'API URL',
         placeholder: s_('PrometheusService|Prometheus API Base URL, like http://prometheus.example.com/'),
         required: true
-      }
-    ]
-
-    if Feature.enabled?(:prometheus_service_iap_auth)
-      result += [
+      },
       {
         type: 'text',
         name: 'google_iap_audience_client_id',
@@ -90,9 +86,6 @@ class PrometheusService < MonitoringService
     ]
   end
 
-    result
-  end
-
   # Check we can connect to the Prometheus API
   def test(*args)
     prometheus_client.ping
@@ -106,7 +99,7 @@ class PrometheusService < MonitoringService
 
     options = { allow_local_requests: allow_local_api_url? }
 
-    if Feature.enabled?(:prometheus_service_iap_auth) && behind_iap?
+    if behind_iap?
       # Adds the Authorization header
       options[:headers] = iap_client.apply({})
     end

changelogs/unreleased/remove-prometheus-iap-feature-flag.yml

+---
+title: Prometheus instances behind Google IAP can now be accessed via manual configurations
+merge_request: 36856
+author:
+type: added

spec/models/project_services/prometheus_service_spec.rb

@@ -262,8 +262,6 @@ RSpec.describe PrometheusService, :use_clean_rails_memory_store_caching do
         service.google_iap_audience_client_id = "IAP_CLIENT_ID.apps.googleusercontent.com"
 
         stub_request(:post, "https://oauth2.googleapis.com/token").to_return(status: 200, body: '{"id_token": "FOO"}', headers: { 'Content-Type': 'application/json; charset=UTF-8' })
-
-        stub_feature_flags(prometheus_service_iap_auth: true)
       end
 
       it 'includes the authorization header' do
@@ -474,11 +472,7 @@ RSpec.describe PrometheusService, :use_clean_rails_memory_store_caching do
           title: 'API URL',
           placeholder: s_('PrometheusService|Prometheus API Base URL, like http://prometheus.example.com/'),
           required: true
-        }
-      ]
-    end
-    let(:feature_flagged_fields) do
-      [
+        },
         {
           type: 'text',
           name: 'google_iap_audience_client_id',
@@ -498,13 +492,7 @@ RSpec.describe PrometheusService, :use_clean_rails_memory_store_caching do
     end
 
     it 'returns fields' do
-      stub_feature_flags(prometheus_service_iap_auth: false)
       expect(service.fields).to eq(expected_fields)
     end
-
-    it 'returns fields with feature flag on' do
-      stub_feature_flags(prometheus_service_iap_auth: true)
-      expect(service.fields).to eq(expected_fields + feature_flagged_fields)
-    end
   end
 end