Extract code that handles graceful termination

pkg/skaffold/build/custom/custom.go

@@ -20,18 +20,15 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"os"
 	"os/exec"
 	"path/filepath"
-	"runtime"
 	"strings"
-	"time"
 
+	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/build/misc"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/constants"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/latest"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/util"
 	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
 )
 
 var (
@@ -65,43 +62,7 @@ func (b *ArtifactBuilder) Build(ctx context.Context, out io.Writer, a *latest.Ar
 		return errors.Wrap(err, "starting cmd")
 	}
 
-	return b.handleGracefulTermination(ctx, cmd)
-}
-
-func (b *ArtifactBuilder) handleGracefulTermination(ctx context.Context, cmd *exec.Cmd) error {
-	done := make(chan struct{})
-	defer close(done)
-
-	go func() {
-		select {
-		case <-ctx.Done():
-			// On windows we can't send specific signals to processes, so we kill the process immediately
-			if runtime.GOOS == "windows" {
-				cmd.Process.Kill()
-				return
-			}
-
-			logrus.Debugf("Sending SIGINT to process %v\n", cmd.Process.Pid)
-			if err := cmd.Process.Signal(os.Interrupt); err != nil {
-				// kill process on error
-				cmd.Process.Kill()
-			}
-
-			// wait 2 seconds or wait for the process to complete
-			select {
-			case <-time.After(2 * time.Second):
-				logrus.Debugf("Killing process %v\n", cmd.Process.Pid)
-				// forcefully kill process after 2 seconds grace period
-				cmd.Process.Kill()
-			case <-done:
-				return
-			}
-		case <-done:
-			return
-		}
-	}()
-
-	return cmd.Wait()
+	return misc.HandleGracefulTermination(ctx, cmd)
 }
 
 func (b *ArtifactBuilder) retrieveCmd(out io.Writer, a *latest.Artifact, tag string) (*exec.Cmd, error) {

pkg/skaffold/build/custom/custom_test.go

@@ -17,12 +17,9 @@ limitations under the License.
 package custom
 
 import (
-	"context"
 	"io/ioutil"
 	"os/exec"
-	"runtime"
 	"testing"
-	"time"
 
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/latest"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/util"
@@ -127,42 +124,6 @@ func TestRetrieveCmd(t *testing.T) {
 	}
 }
 
-func TestGracefulBuildCancel(t *testing.T) {
-	if runtime.GOOS == "windows" {
-		t.Skip("graceful cancel doesn't work on windows")
-	}
-
-	tests := []struct {
-		description string
-		command     string
-		shouldErr   bool
-	}{
-		{
-			description: "terminate gracefully and exit 0",
-			command:     "trap 'echo trap' INT; sleep 2",
-		}, {
-			description: "terminate gracefully and kill process",
-			command:     "trap 'echo trap' INT; sleep 5",
-			shouldErr:   true,
-		},
-	}
-
-	for _, test := range tests {
-		testutil.Run(t, test.description, func(t *testutil.T) {
-			builder := NewArtifactBuilder(false, nil)
-			ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
-
-			cmd := exec.Command("bash", "-c", test.command)
-			t.CheckNoError(cmd.Start())
-
-			err := builder.handleGracefulTermination(ctx, cmd)
-			t.CheckError(test.shouldErr, err)
-
-			cancel()
-		})
-	}
-}
-
 func expectedCmd(buildCommand, dir string, args, env []string) *exec.Cmd {
 	cmd := exec.Command(buildCommand, args...)
 	cmd.Dir = dir

pkg/skaffold/build/misc/graceful.go

@@ -0,0 +1,63 @@
+/*
+Copyright 2019 The Skaffold 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 misc
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"runtime"
+	"time"
+
+	"github.com/sirupsen/logrus"
+)
+
+func HandleGracefulTermination(ctx context.Context, cmd *exec.Cmd) error {
+	done := make(chan struct{})
+	defer close(done)
+
+	go func() {
+		select {
+		case <-ctx.Done():
+			// On windows we can't send specific signals to processes, so we kill the process immediately
+			if runtime.GOOS == "windows" {
+				cmd.Process.Kill()
+				return
+			}
+
+			logrus.Debugf("Sending SIGINT to process %v\n", cmd.Process.Pid)
+			if err := cmd.Process.Signal(os.Interrupt); err != nil {
+				// kill process on error
+				cmd.Process.Kill()
+			}
+
+			// wait 2 seconds or wait for the process to complete
+			select {
+			case <-time.After(2 * time.Second):
+				logrus.Debugf("Killing process %v\n", cmd.Process.Pid)
+				// forcefully kill process after 2 seconds grace period
+				cmd.Process.Kill()
+			case <-done:
+				return
+			}
+		case <-done:
+			return
+		}
+	}()
+
+	return cmd.Wait()
+}

pkg/skaffold/build/misc/graceful_test.go

@@ -0,0 +1,62 @@
+/*
+Copyright 2019 The Skaffold 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 misc
+
+import (
+	"context"
+	"os/exec"
+	"runtime"
+	"testing"
+	"time"
+
+	"github.com/GoogleContainerTools/skaffold/testutil"
+)
+
+func TestGracefulBuildCancel(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("graceful cancel doesn't work on windows")
+	}
+
+	tests := []struct {
+		description string
+		command     string
+		shouldErr   bool
+	}{
+		{
+			description: "terminate gracefully and exit 0",
+			command:     "trap 'echo trap' INT; sleep 2",
+		}, {
+			description: "terminate gracefully and kill process",
+			command:     "trap 'echo trap' INT; sleep 5",
+			shouldErr:   true,
+		},
+	}
+
+	for _, test := range tests {
+		testutil.Run(t, test.description, func(t *testutil.T) {
+			ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+
+			cmd := exec.Command("bash", "-c", test.command)
+			t.CheckNoError(cmd.Start())
+
+			err := HandleGracefulTermination(ctx, cmd)
+			t.CheckError(test.shouldErr, err)
+
+			cancel()
+		})
+	}
+}