Convert to controller runtime runnables (#4202)

- controller runtime manages controllers and other runnables (previously
goroutines added to the server workgroup)
- leader election now uses a combination of configmap and lease objects,
in a future release we can move to just leases
- controllers and other components are currently not dependent on leader election
- other components (status writers) are set to be dependent on leader
election
- adds to the leaderelection e2e tests to check on leaderelection
configmap in addition to new lease resource and events

Signed-off-by: Sunjay Bhatia <sunjayb@vmware.com>

Makefile

@@ -205,7 +205,7 @@ lint-flags:
 
 .PHONY: generate
 generate: ## Re-generate generated code and documentation
-generate: generate-rbac generate-crd-deepcopy generate-crd-yaml generate-gateway-crd-yaml generate-deployment generate-api-docs generate-metrics-docs generate-uml
+generate: generate-rbac generate-crd-deepcopy generate-crd-yaml generate-gateway-crd-yaml generate-deployment generate-api-docs generate-metrics-docs generate-uml generate-go
 
 .PHONY: generate-rbac
 generate-rbac:
@@ -240,9 +240,14 @@ generate-api-docs:
 
 .PHONY: generate-metrics-docs
 generate-metrics-docs:
-	@echo Generating metrics documentation ...
+	@echo "Generating metrics documentation..."
 	@cd site/content/guides/metrics && rm -f *.md && go run ../../../../hack/generate-metrics-doc.go
 
+.PHONY: generate-go
+generate-go:
+	@echo "Generating mocks..."
+	@go generate ./...
+
 .PHONY: check-generate
 check-generate: generate
 	@./hack/actions/check-uncommitted-codegen.sh

changelogs/unreleased/4202-sunjayBhatia-minor.md

@@ -0,0 +1,8 @@
+### Transition to controller-runtime managed leader election
+
+Contour now utilizes [controller-runtime](https://github.com/kubernetes-sigs/controller-runtime) Manager based leader election and coordination of subroutines.
+With this change, Contour is also transitioning away from using a ConfigMap for leader election.
+In this release, Contour now uses a combination of ConfigMap and Lease object.
+A future release will remove usage of the ConfigMap resource for leader election.
+
+This change should be a no-op for most users, however be sure to re-apply the relevant parts of your deployment for RBAC to ensure Contour has access to Lease and Event objects (this would be the ClusterRole in the provided example YAML).

cmd/contour/ingressstatus.go

@@ -48,23 +48,16 @@ import (
 type loadBalancerStatusWriter struct {
 	log              logrus.FieldLogger
 	cache            cache.Cache
-	isLeader         chan struct{}
 	lbStatus         chan v1.LoadBalancerStatus
 	statusUpdater    k8s.StatusUpdater
 	ingressClassName string
 }
 
-func (isw *loadBalancerStatusWriter) Start(stop <-chan struct{}) error {
-	// Await leadership election.
-	isw.log.Info("awaiting leadership election")
-	select {
-	case <-stop:
-		// We were asked to stop before elected leader.
-		return nil
-	case <-isw.isLeader:
-		isw.log.Info("elected leader")
-	}
+func (isw *loadBalancerStatusWriter) NeedLeaderElection() bool {
+	return true
+}
 
+func (isw *loadBalancerStatusWriter) Start(ctx context.Context) error {
 	u := &k8s.StatusAddressUpdater{
 		Logger: func() logrus.FieldLogger {
 			// Configure the StatusAddressUpdater logger.
@@ -98,7 +91,7 @@ func (isw *loadBalancerStatusWriter) Start(stop <-chan struct{}) error {
 
 	for {
 		select {
-		case <-stop:
+		case <-ctx.Done():
 			// Once started, there's no way to stop the
 			// informer from here. Clear the load balancer
 			// status so that subsequent informer events

cmd/contour/ingressstatus_test.go

@@ -18,7 +18,9 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	v1 "k8s.io/api/core/v1"
+	"sigs.k8s.io/controller-runtime/pkg/manager"
 )
 
 func Test_parseStatusFlag(t *testing.T) {
@@ -194,3 +196,8 @@ func Test_lbAddress(t *testing.T) {
 		})
 	}
 }
+
+func TestRequireLeaderElection(t *testing.T) {
+	var l manager.LeaderElectionRunnable = &loadBalancerStatusWriter{}
+	require.True(t, l.NeedLeaderElection())
+}