K8SPG-614: Enable leader election (#997)

* Enable leader election.

* Make leader election setting configurable.

* Fix unit test.

Author: inelpandzic

cmd/postgres-operator/main.go

@@ -27,7 +27,6 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/manager"
 
 	//"github.com/percona/percona-postgresql-operator/internal/controller/pgupgrade"
-
 	"github.com/percona/percona-postgresql-operator/internal/controller/pgupgrade"
 	"github.com/percona/percona-postgresql-operator/internal/controller/postgrescluster"
 	"github.com/percona/percona-postgresql-operator/internal/controller/runtime"
@@ -106,6 +105,7 @@ func main() {
 		namespaces,
 		cfg,
 		false,
+		false,
 		features,
 	)
 	assertNoError(err)

percona/controller/pgcluster/controller_test.go

@@ -484,7 +484,7 @@ var _ = Describe("Watching secrets", Ordered, func() {
 		Expect(err).NotTo(HaveOccurred())
 
 		Expect(err).To(Not(HaveOccurred()))
-		mgr, err := runtime.CreateRuntimeManager(namespace.Name, cfg, true, gate)
+		mgr, err := runtime.CreateRuntimeManager(namespace.Name, cfg, true, true, gate)
 		Expect(err).To(Succeed())
 		Expect(v2.AddToScheme(mgr.GetScheme())).To(Succeed())
 

percona/runtime/runtime.go

@@ -19,13 +19,20 @@ var refreshInterval = 60 * time.Minute
 
 // CreateRuntimeManager does the same thing as `internal/controller/runtime.CreateRuntimeManager`,
 // excet it configures the manager to watch multiple namespaces.
-func CreateRuntimeManager(namespaces string, config *rest.Config, disableMetrics bool, features feature.MutableGate) (manager.Manager, error) {
+func CreateRuntimeManager(namespaces string, config *rest.Config, disableMetrics, disableLeaderElection bool, features feature.MutableGate) (manager.Manager, error) {
 
 	options := manager.Options{
 		Cache: cache.Options{
 			SyncPeriod: &refreshInterval,
 		},
-		Scheme: r.Scheme,
+		Scheme:           r.Scheme,
+		LeaderElection:   disableLeaderElection,
+		LeaderElectionID: "08db3feb.percona.com",
+	}
+
+	if disableLeaderElection {
+		options.LeaderElection = false
+		options.LeaderElectionID = ""
 	}
 
 	options.BaseContext = func() context.Context {