runtime: Add more debug logs for container io stream copy

This can help debugging container lifecycle issues

Fixes: #3913

Signed-off-by: Feng Wang <feng.wang@databricks.com>

src/runtime/pkg/containerd-shim-v2/start.go

@@ -8,12 +8,14 @@ package containerdshim
 import (
 	"context"
 	"fmt"
+	"github.com/sirupsen/logrus"
 
 	"github.com/containerd/containerd/api/types/task"
 	"github.com/kata-containers/kata-containers/src/runtime/pkg/katautils"
 )
 
 func startContainer(ctx context.Context, s *service, c *container) (retErr error) {
+	shimLog.WithField("container", c.id).Debug("start container")
 	defer func() {
 		if retErr != nil {
 			// notify the wait goroutine to continue
@@ -78,7 +80,8 @@ func startContainer(ctx context.Context, s *service, c *container) (retErr error
 			return err
 		}
 		c.ttyio = tty
-		go ioCopy(c.exitIOch, c.stdinCloser, tty, stdin, stdout, stderr)
+
+		go ioCopy(shimLog.WithField("container", c.id), c.exitIOch, c.stdinCloser, tty, stdin, stdout, stderr)
 	} else {
 		// close the io exit channel, since there is no io for this container,
 		// otherwise the following wait goroutine will hang on this channel.
@@ -94,6 +97,10 @@ func startContainer(ctx context.Context, s *service, c *container) (retErr error
 }
 
 func startExec(ctx context.Context, s *service, containerID, execID string) (e *exec, retErr error) {
+	shimLog.WithFields(logrus.Fields{
+		"container": containerID,
+		"exec":      execID,
+	}).Debug("start container execution")
 	// start an exec
 	c, err := s.getContainer(containerID)
 	if err != nil {
@@ -140,7 +147,10 @@ func startExec(ctx context.Context, s *service, containerID, execID string) (e *
 	}
 	execs.ttyio = tty
 
-	go ioCopy(execs.exitIOch, execs.stdinCloser, tty, stdin, stdout, stderr)
+	go ioCopy(shimLog.WithFields(logrus.Fields{
+		"container": c.id,
+		"exec":      execID,
+	}), execs.exitIOch, execs.stdinCloser, tty, stdin, stdout, stderr)
 
 	go wait(ctx, s, c, execID)
 

src/runtime/pkg/containerd-shim-v2/stream.go

@@ -12,6 +12,7 @@ import (
 	"syscall"
 
 	"github.com/containerd/fifo"
+	"github.com/sirupsen/logrus"
 )
 
 // The buffer size used to specify the buffer for IO streams copy
@@ -86,25 +87,28 @@ func newTtyIO(ctx context.Context, stdin, stdout, stderr string, console bool) (
 	return ttyIO, nil
 }
 
-func ioCopy(exitch, stdinCloser chan struct{}, tty *ttyIO, stdinPipe io.WriteCloser, stdoutPipe, stderrPipe io.Reader) {
+func ioCopy(shimLog *logrus.Entry, exitch, stdinCloser chan struct{}, tty *ttyIO, stdinPipe io.WriteCloser, stdoutPipe, stderrPipe io.Reader) {
 	var wg sync.WaitGroup
 
 	if tty.Stdin != nil {
 		wg.Add(1)
 		go func() {
+			shimLog.Debug("stdin io stream copy started")
 			p := bufPool.Get().(*[]byte)
 			defer bufPool.Put(p)
 			io.CopyBuffer(stdinPipe, tty.Stdin, *p)
 			// notify that we can close process's io safely.
 			close(stdinCloser)
 			wg.Done()
+			shimLog.Debug("stdin io stream copy exited")
 		}()
 	}
 
 	if tty.Stdout != nil {
 		wg.Add(1)
 
 		go func() {
+			shimLog.Debug("stdout io stream copy started")
 			p := bufPool.Get().(*[]byte)
 			defer bufPool.Put(p)
 			io.CopyBuffer(tty.Stdout, stdoutPipe, *p)
@@ -113,20 +117,24 @@ func ioCopy(exitch, stdinCloser chan struct{}, tty *ttyIO, stdinPipe io.WriteClo
 				// close stdin to make the other routine stop
 				tty.Stdin.Close()
 			}
+			shimLog.Debug("stdout io stream copy exited")
 		}()
 	}
 
 	if tty.Stderr != nil && stderrPipe != nil {
 		wg.Add(1)
 		go func() {
+			shimLog.Debug("stderr io stream copy started")
 			p := bufPool.Get().(*[]byte)
 			defer bufPool.Put(p)
 			io.CopyBuffer(tty.Stderr, stderrPipe, *p)
 			wg.Done()
+			shimLog.Debug("stderr io stream copy exited")
 		}()
 	}
 
 	wg.Wait()
 	tty.close()
 	close(exitch)
+	shimLog.Debug("all io stream copy goroutines exited")
 }

src/runtime/pkg/containerd-shim-v2/stream_test.go

@@ -7,6 +7,7 @@ package containerdshim
 
 import (
 	"context"
+	"github.com/sirupsen/logrus"
 	"io"
 	"os"
 	"path/filepath"
@@ -179,7 +180,7 @@ func TestIoCopy(t *testing.T) {
 		defer tty.close()
 
 		// start the ioCopy threads : copy from src to dst
-		go ioCopy(exitioch, stdinCloser, tty, dstInW, srcOutR, srcErrR)
+		go ioCopy(logrus.WithContext(context.Background()), exitioch, stdinCloser, tty, dstInW, srcOutR, srcErrR)
 
 		var firstW, secondW, thirdW io.WriteCloser
 		var firstR, secondR, thirdR io.Reader

src/runtime/pkg/containerd-shim-v2/wait.go

@@ -31,12 +31,17 @@ func wait(ctx context.Context, s *service, c *container, execID string) (int32,
 	if execID == "" {
 		//wait until the io closed, then wait the container
 		<-c.exitIOch
+		shimLog.WithField("container", c.id).Debug("The container io streams closed")
 	} else {
 		execs, err = c.getExec(execID)
 		if err != nil {
 			return exitCode255, err
 		}
 		<-execs.exitIOch
+		shimLog.WithFields(logrus.Fields{
+			"container": c.id,
+			"exec":      execID,
+		}).Debug("The container process io streams closed")
 		//This wait could be triggered before exec start which
 		//will get the exec's id, thus this assignment must after
 		//the exec exit, to make sure it get the exec's id.
@@ -82,13 +87,17 @@ func wait(ctx context.Context, s *service, c *container, execID string) (int32,
 		c.exitTime = timeStamp
 
 		c.exitCh <- uint32(ret)
-
+		shimLog.WithField("container", c.id).Debug("The container status is StatusStopped")
 	} else {
 		execs.status = task.StatusStopped
 		execs.exitCode = ret
 		execs.exitTime = timeStamp
 
 		execs.exitCh <- uint32(ret)
+		shimLog.WithFields(logrus.Fields{
+			"container": c.id,
+			"exec":      execID,
+		}).Debug("The container exec status is StatusStopped")
 	}
 	s.mu.Unlock()