Call the quit when the eventshub is closed (#593)

Co-authored-by: Chris Suszyński <[email protected]>

pkg/eventshub/eventshub.go

@@ -23,6 +23,7 @@ import (
 	"golang.org/x/sync/errgroup"
 	"knative.dev/pkg/injection"
 	"knative.dev/pkg/logging"
+	"knative.dev/pkg/signals"
 )
 
 type envConfig struct {
@@ -39,8 +40,9 @@ type EventGeneratorStarter func(context.Context, *EventLogs) error
 // Start starts a new eventshub process, with the provided factories.
 // You can create your own eventshub providing event log factories and event generator factories.
 func Start(eventLogFactories map[string]EventLogFactory, eventGeneratorFactories map[string]EventGeneratorStarter) {
-	//nolint // nil ctx is fine here, look at the code of EnableInjectionOrDie
-	ctx, _ := injection.EnableInjectionOrDie(nil, nil)
+	ctx := signals.NewContext()
+	defer maybeQuitIstioProxy(ctx) // quit at exit
+	ctx, _ = injection.EnableInjectionOrDie(ctx, nil)
 	ctx = ConfigureLogging(ctx, "eventshub")
 
 	tracer, err := ConfigureTracing(logging.FromContext(ctx), "")

pkg/eventshub/istio_quit.go

@@ -0,0 +1,38 @@
+/*
+Copyright 2023 The Knative Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package eventshub
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"syscall"
+
+	"knative.dev/pkg/logging"
+)
+
+// maybeQuitIstioProxy shuts down Istio's proxy when available.
+func maybeQuitIstioProxy(ctx context.Context) {
+	log := logging.FromContext(ctx)
+	req, _ := http.NewRequest(http.MethodPost, "http://localhost:15020/quitquitquit", nil)
+
+	_, err := http.DefaultClient.Do(req)
+
+	if err != nil && !errors.Is(err, syscall.ECONNREFUSED) {
+		log.Warn("Ignore this warning if Istio proxy is not used on this pod", err)
+	}
+}