[8.x](backport #40918) x-pack/metricbeat/module/gcp: Override GCP API endpoint in metric client

CHANGELOG.next.asciidoc

@@ -62,6 +62,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Mark system process metricsets as running if metrics are partially available {pull}40565[40565]
 - Added back `elasticsearch.node.stats.jvm.mem.pools.*` to the `node_stats` metricset {pull}40571[40571]
 - Add support for snapshot in vSphere virtualmachine metricset {pull}40683[40683]
+- Add support for specifying a custom endpoint for GCP service clients. {issue}40848[40848] {pull}40918[40918]
 
 *Osquerybeat*
 

metricbeat/docs/modules/gcp.asciidoc

@@ -52,6 +52,8 @@ and metadata information from metricsets and fetch metrics only. At the moment,
 
 * *period*: A single time duration specified for this module collection frequency.
 
+* *endpoint*: A custom endpoint to use for the GCP API calls. If not specified, the default endpoint will be used.
+
 [float]
 == Example configuration
 * `compute` metricset is enabled to collect metrics from `us-central1-a` zone
@@ -334,6 +336,7 @@ metricbeat.modules:
   period: 24h
   project_id: "your project id"
   credentials_file_path: "your JSON credentials file path"
+  endpoint: http://your-endpoint
   dataset_id: "dataset id"
   table_pattern: "table pattern"
 ----

x-pack/metricbeat/metricbeat.reference.yml

@@ -641,6 +641,7 @@ metricbeat.modules:
   period: 24h
   project_id: "your project id"
   credentials_file_path: "your JSON credentials file path"
+  endpoint: http://your-endpoint
   dataset_id: "dataset id"
   table_pattern: "table pattern"
 

x-pack/metricbeat/module/gcp/_meta/config.yml

@@ -67,5 +67,6 @@
   period: 24h
   project_id: "your project id"
   credentials_file_path: "your JSON credentials file path"
+  endpoint: http://your-endpoint
   dataset_id: "dataset id"
   table_pattern: "table pattern"

x-pack/metricbeat/module/gcp/_meta/docs.asciidoc

@@ -40,6 +40,8 @@ and metadata information from metricsets and fetch metrics only. At the moment,
 
 * *period*: A single time duration specified for this module collection frequency.
 
+* *endpoint*: A custom endpoint to use for the GCP API calls. If not specified, the default endpoint will be used.
+
 [float]
 == Example configuration
 * `compute` metricset is enabled to collect metrics from `us-central1-a` zone

x-pack/metricbeat/module/gcp/metrics/metricset.go

@@ -105,6 +105,7 @@ type config struct {
 	ExcludeLabels       bool     `config:"exclude_labels"`
 	CredentialsFilePath string   `config:"credentials_file_path"`
 	CredentialsJSON     string   `config:"credentials_json"`
+	Endpoint            string   `config:"endpoint"`
 
 	opt    []option.ClientOption
 	period *durationpb.Duration
@@ -139,6 +140,11 @@ func New(base mb.BaseMetricSet) (mb.MetricSet, error) {
 		return m, fmt.Errorf("no credentials_file_path or credentials_json specified")
 	}
 
+	if m.config.Endpoint != "" {
+		m.Logger().Warnf("You are using a custom endpoint '%s' for the GCP API calls.", m.config.Endpoint)
+		m.config.opt = append(m.config.opt, option.WithEndpoint(m.config.Endpoint))
+	}
+
 	m.config.period = &durationpb.Duration{
 		Seconds: int64(m.Module().Config().Period.Seconds()),
 	}

x-pack/metricbeat/modules.d/gcp.yml.disabled

@@ -70,5 +70,6 @@
   period: 24h
   project_id: "your project id"
   credentials_file_path: "your JSON credentials file path"
+  endpoint: http://your-endpoint
   dataset_id: "dataset id"
   table_pattern: "table pattern"