Revert "prometheus: active worker gauge"

This reverts commit 68bc8e0c88.

internal/prometheus/worker_metrics.go

@@ -1,23 +0,0 @@
-package prometheus
-
-import (
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
-)
-
-var (
-	ActiveWorkers = promauto.NewGaugeVec(prometheus.GaugeOpts{
-		Name:      "active_workers",
-		Namespace: Namespace,
-		Subsystem: WorkerSubsystem,
-		Help:      "Active workers",
-	}, []string{"worker", "tenant", "arch"})
-)
-
-func AddActiveWorker(worker, tenant, arch string) {
-	ActiveWorkers.WithLabelValues(worker, tenant, arch).Inc()
-}
-
-func RemoveActiveWorker(worker, tenant, arch string) {
-	ActiveWorkers.WithLabelValues(worker, tenant, arch).Dec()
-}

internal/worker/server.go

@@ -168,9 +168,7 @@ func (s *Server) WatchWorkers() {
 			err = s.jobs.DeleteWorker(w.ID)
 			if err != nil {
 				logrus.Warningf("Unable to remove worker: %v", err)
-				continue
 			}
-			prometheus.RemoveActiveWorker(w.ID.String(), w.Channel, w.Arch)
 		}
 	}
 }
@@ -830,7 +828,6 @@ func (s *Server) RegisterWorker(c, a string) (uuid.UUID, error) {
 	if err != nil {
 		return uuid.Nil, err
 	}
-	prometheus.AddActiveWorker(workerID.String(), c, a)
 	logrus.Infof("Worker (%v) registered", a)
 	return workerID, nil
 }