ACCDT-1238: Add runner_name label (#2)

* add runner_name as extra label

* check for existence of runner name

* keep consistency of cardinality

pkg/actionsmetrics/event_reader.go

@@ -137,7 +137,11 @@ func (reader *EventReader) ProcessWorkflowJobEvent(ctx context.Context, event in
 		githubWorkflowJobQueueDurationSeconds.With(labels).Observe(parseResult.QueueTime.Seconds())
 
 	case "completed":
-		githubWorkflowJobsCompletedTotal.With(labels).Inc()
+		var rn string
+		if n := e.WorkflowJob.RunnerName; n != nil {
+			rn = *n
+		}
+		githubWorkflowJobsCompletedTotal.With(extraLabel("runner_name", rn, labels)).Inc()
 
 		// job_conclusion -> (neutral, success, skipped, cancelled, timed_out, action_required, failure)
 		githubWorkflowJobConclusionsTotal.With(extraLabel("job_conclusion", *e.WorkflowJob.Conclusion, labels)).Inc()

pkg/actionsmetrics/metrics.go

@@ -175,7 +175,7 @@ var (
 			Name: "github_workflow_jobs_completed_total",
 			Help: "Total count of workflow jobs completed (events where job_status=completed)",
 		},
-		metricLabels(),
+		metricLabels("runner_name"),
 	)
 	githubWorkflowJobFailuresTotal = prometheus.NewCounterVec(
 		prometheus.CounterOpts{