Move pkg/signals from dapr/dapr to kit (dapr#70)

No code changes

Signed-off-by: ItalyPaleAle <[email protected]>

Author: ItalyPaleAle

signals/signals.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2023 The Dapr 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"
+
+	"github.com/dapr/kit/logger"
+)
+
+var (
+	log = logger.NewLogger("dapr.signals")
+
+	// Inspired by
+	// https://github.com/kubernetes-sigs/controller-runtime/blob/8499b67e316a03b260c73f92d0380de8cd2e97a1/pkg/manager/signals/signal.go#L25
+	onlyOneSignalHandler = make(chan struct{})
+)
+
+// Context returns a context which will be canceled when either the SIGINT
+// (windows and non windows) or SIGTERM (non windows) signal is caught. If
+// either signal is caught a second time, the program is terminated immediately
+// with exit code 1.
+func Context() context.Context {
+	// panics when called twice
+	close(onlyOneSignalHandler)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, shutdownSignals...)
+
+	go func() {
+		sig := <-sigCh
+		log.Infof(`Received signal '%s'; beginning shutdown`, sig)
+		cancel()
+		sig = <-sigCh
+		log.Fatalf(
+			`Received signal '%s' during shutdown; exiting immediately`,
+			sig,
+		)
+	}()
+
+	return ctx
+}

signals/signals_posix.go

@@ -0,0 +1,24 @@
+//go:build !windows
+// +build !windows
+
+/*
+Copyright 2023 The Dapr 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}

signals/signals_posix_test.go

@@ -0,0 +1,45 @@
+//go:build !windows
+// +build !windows
+
+/*
+Copyright 2023 The Dapr 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
+
+// Note this file is not built on Windows, as we depend on syscall methods not available on Windows.
+
+import (
+	"os/signal"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestContext(t *testing.T) {
+	signal.Reset()
+
+	t.Run("if receive signal, should cancel context", func(t *testing.T) {
+		defer signal.Reset()
+		onlyOneSignalHandler = make(chan struct{})
+
+		ctx := Context()
+		assert.NoError(t, syscall.Kill(syscall.Getpid(), syscall.SIGINT))
+		select {
+		case <-ctx.Done():
+		case <-time.After(1 * time.Second):
+			t.Error("context should be cancelled in time")
+		}
+	})
+}

signals/signals_windows.go

@@ -0,0 +1,20 @@
+/*
+Copyright 2023 The Dapr 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}