x-pack/filebeat/input/gcppubsub: fix integration tests (#45150)

Solved two issues in the GCP Pub/Sub input tests:

- GCP Pub/Sub Emulator Container Missing: this has been fixed by ensuring 
  the Pub/Sub emulator Docker container is properly launched for the test environment.

- Fix for Segfault in NewInput.func2: a segmentation fault occurred when test code 
  accessed in.metrics before it was initialized. Metrics are now explicitly initialized 
  in the test setup to avoid nil pointer dereferencing.

Author: chemamartinez

CHANGELOG-developer.next.asciidoc

@@ -115,6 +115,7 @@ The list below covers the major changes between 7.0.0-rc2 and main only.
 - Fix IIS module logging errors in case application pool PDH counter is not found. {pull}42274[42274]
 - Removed direct dependency on Azure/go-autorest/autorest/adal, which is deprecated. {issue}41463[41463] {pull}42959[42959]
 - Fixed flaky zookeeper integration tests. {pull}43638[43638]
+- Fixed Fileebat GCP Pub/Sub input integration tests. {pull}45150[45150]
 
 ==== Added
 

dev-tools/mage/integtest_docker.go

@@ -191,6 +191,8 @@ func WithGoIntegTestHostEnv(env map[string]string) map[string]string {
 	// images for the next release after a feature freeze, which causes temporary test failures.
 	env["TESTING_FILEBEAT_ALLOW_OLDER"] = "1"
 
+	env["PUBSUB_EMULATOR_HOST"] = "localhost:8432"
+
 	return env
 }
 

x-pack/filebeat/input/gcppubsub/_meta/Dockerfile renamed to testing/environments/docker/googlepubsub/Dockerfile

@@ -20,6 +20,16 @@ services:
     ports:
       - 9200:9200
 
+  googlepubsub:
+    image: docker.elastic.co/integrations-ci/beats-googlepubsub:emulator-${SDK_VERSION:-398.0.0-0}-1
+    build:
+      context: ${ES_BEATS}/testing/environments/docker/googlepubsub
+      args:
+        SDK_VERSION: ${SDK_VERSION:-398.0.0-0}
+    hostname: googlepubsub
+    ports:
+      - 8432:8432
+
   cometd:
     build: ${ES_BEATS}/testing/environments/docker/cometd
     hostname: cometd

x-pack/filebeat/input/gcppubsub/_meta/supported-versions.yml renamed to testing/environments/docker/googlepubsub/supported-versions.yml

@@ -20,6 +20,16 @@ services:
     ports:
       - 9200:9200
 
+  googlepubsub:
+    image: docker.elastic.co/integrations-ci/beats-googlepubsub:emulator-${SDK_VERSION:-398.0.0-0}-1
+    build:
+      context: ${ES_BEATS}/testing/environments/docker/googlepubsub
+      args:
+        SDK_VERSION: ${SDK_VERSION:-398.0.0-0}
+    hostname: googlepubsub
+    ports:
+      - 8432:8432
+
   cometd:
     build: ${ES_BEATS}/testing/environments/docker/cometd
     hostname: cometd

x-pack/agentbeat/docker-compose.yml

@@ -251,6 +251,8 @@ func runTestWithACKer(t *testing.T, cfg *conf.C, onEvent eventHandler, run func(
 	}
 	//nolint:errcheck // ignore
 	pubsubInput := in.(*pubsubInput)
+	// Initialize metrics explicitly for tests
+	pubsubInput.metrics = newInputMetrics("", nil)
 	defer pubsubInput.Stop()
 
 	run(client, pubsubInput, eventOutlet, t)