Fix deprecated code with the k8s signal context

Signed-off-by: Jorge Turrado <jorge_turrado@hotmail.es>

Author: JorTurFer

pkg/cmd/builder.go

@@ -17,6 +17,7 @@ limitations under the License.
 package cmd
 
 import (
+"context"
 "fmt"
 "sync"
 "time"
@@ -360,11 +361,11 @@ func (b *AdapterBase) Informers() (informers.SharedInformerFactory, error) {
 }
 
 // Run runs this custom metrics adapter until the given stop channel is closed.
-func (b *AdapterBase) Run(stopCh <-chan struct{}) error {
+func (b *AdapterBase) Run(ctx context.Context) error {
 server, err := b.Server()
 if err != nil {
 return err
 }
 
-return server.GenericAPIServer.PrepareRun().Run(stopCh)
+return server.GenericAPIServer.PrepareRun().RunWithContext(ctx)
 }

test-adapter/main.go

@@ -22,7 +22,6 @@ import (
 "time"
 
 "github.com/emicklei/go-restful/v3"
-"k8s.io/apimachinery/pkg/util/wait"
 "k8s.io/component-base/logs"
 "k8s.io/component-base/metrics/legacyregistry"
 "k8s.io/klog/v2"
@@ -31,6 +30,7 @@ import (
 basecmd "sigs.k8s.io/custom-metrics-apiserver/pkg/cmd"
 "sigs.k8s.io/custom-metrics-apiserver/pkg/provider"
 fakeprov "sigs.k8s.io/custom-metrics-apiserver/test-adapter/provider"
+"sigs.k8s.io/custom-metrics-apiserver/test-adapter/signals"
 )
 
 type SampleAdapter struct {
@@ -86,7 +86,7 @@ func main() {
 }
 klog.Fatal(server.ListenAndServe())
 }()
-if err := cmd.Run(wait.NeverStop); err != nil {
+if err := cmd.Run(signals.SetupSignalHandler()); err != nil {
 klog.Fatalf("unable to run custom metrics adapter: %v", err)
 }
 }

test-adapter/signals/signal.go

@@ -0,0 +1,45 @@
+/*
+Copyright 2017 The Kubernetes 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
+
+ http://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 signals
+
+import (
+"context"
+"os"
+"os/signal"
+)
+
+var onlyOneSignalHandler = make(chan struct{})
+
+// SetupSignalHandler registers for SIGTERM and SIGINT. A context is returned
+// which is canceled on one of these signals. If a second signal is caught, the program
+// is terminated with exit code 1.
+func SetupSignalHandler() context.Context {
+close(onlyOneSignalHandler) // panics when called twice
+
+ctx, cancel := context.WithCancel(context.Background())
+
+c := make(chan os.Signal, 2)
+signal.Notify(c, shutdownSignals...)
+go func() {
+<-c
+cancel()
+<-c
+os.Exit(1) // second signal. Exit directly.
+}()
+
+return ctx
+}

test-adapter/signals/signal_posix.go

@@ -0,0 +1,27 @@
+//go:build !windows
+// +build !windows
+
+/*
+Copyright 2017 The Kubernetes 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
+
+ http://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 signals
+
+import (
+"os"
+"syscall"
+)
+
+var shutdownSignals = []os.Signal{os.Interrupt, syscall.SIGTERM}

test-adapter/signals/signal_windows.go

@@ -0,0 +1,23 @@
+/*
+Copyright 2017 The Kubernetes 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
+
+ http://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 signals
+
+import (
+"os"
+)
+
+var shutdownSignals = []os.Signal{os.Interrupt}