fix: panic in Logger.Stop (#9159)

There was a panic being caused in Logger.Stop() (Possibly from 97de7db) because threadLogsCancel might be nil if Stop was called before Start, this just initialises it to a noop function.

pkg/skaffold/docker/logger/log.go

@@ -71,6 +71,7 @@ func NewLogger(ctx context.Context, tracker *tracker.ContainerTracker, cfg docke
 		client:              cli,
 		colorPicker:         output.NewColorPicker(),
 		shouldInterruptLogs: shouldInterruptLogs,
+		threadLogsCancel:    func() {},
 	}, nil
 }
 

pkg/skaffold/docker/logger/log_test.go

@@ -20,6 +20,10 @@ import (
 	"context"
 	"io"
 	"testing"
+
+	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/docker"
+	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/docker/tracker"
+	"github.com/GoogleContainerTools/skaffold/v2/testutil"
 )
 
 func TestDockerLoggerZeroValue(t *testing.T) {
@@ -31,3 +35,16 @@ func TestDockerLoggerZeroValue(t *testing.T) {
 	m.Unmute()
 	m.Stop()
 }
+
+func TestLoggerStopNoPanic(t *testing.T) {
+	testutil.Run(t, "stopping logger should not panic", func(t *testutil.T) {
+		t.Override(&docker.NewAPIClient, func(context.Context, docker.Config) (docker.LocalDaemon, error) {
+			return nil, nil
+		})
+
+		logger, err := NewLogger(context.Background(), &tracker.ContainerTracker{}, nil, true)
+		testutil.CheckError(t.T, false, err)
+
+		logger.Stop()
+	})
+}