attach: wait for exit code from ContainerWait

Such as with `docker run`, if a user CTRL-Cs while attached to a
container, we should forward the signal and wait for the exit from
`ContainerWait`, instead of just returning.

Signed-off-by: Laura Brehm <laurabrehm@hey.com>

Author: laurazard

cli/command/container/attach.go

@@ -72,7 +72,8 @@ func RunAttach(ctx context.Context, dockerCLI command.Cli, containerID string, o
 	apiClient := dockerCLI.Client()
 
 	// request channel to wait for client
-	resultC, errC := apiClient.ContainerWait(ctx, containerID, "")
+	waitCtx := context.WithoutCancel(ctx)
+	resultC, errC := apiClient.ContainerWait(waitCtx, containerID, "")
 
 	c, err := inspectContainerAndCheckState(ctx, apiClient, containerID)
 	if err != nil {
@@ -163,9 +164,6 @@ func getExitStatus(errC <-chan error, resultC <-chan container.WaitResponse) err
 			return cli.StatusError{StatusCode: int(result.StatusCode)}
 		}
 	case err := <-errC:
-		if errors.Is(err, context.Canceled) {
-			return nil
-		}
 		return err
 	}
 

cli/command/container/attach_test.go

@@ -1,7 +1,6 @@
 package container
 
 import (
-	"context"
 	"io"
 	"testing"
 
@@ -86,11 +85,7 @@ func TestNewAttachCommandErrors(t *testing.T) {
 }
 
 func TestGetExitStatus(t *testing.T) {
-	var (
-		expectedErr = errors.New("unexpected error")
-		errC        = make(chan error, 1)
-		resultC     = make(chan container.WaitResponse, 1)
-	)
+	expectedErr := errors.New("unexpected error")
 
 	testcases := []struct {
 		result        *container.WaitResponse
@@ -118,20 +113,20 @@ func TestGetExitStatus(t *testing.T) {
 			},
 			expectedError: cli.StatusError{StatusCode: 15},
 		},
-		{
-			err:           context.Canceled,
-			expectedError: nil,
-		},
 	}
 
 	for _, testcase := range testcases {
+		errC := make(chan error, 1)
+		resultC := make(chan container.WaitResponse, 1)
 		if testcase.err != nil {
 			errC <- testcase.err
 		}
 		if testcase.result != nil {
 			resultC <- *testcase.result
 		}
+
 		err := getExitStatus(errC, resultC)
+
 		if testcase.expectedError == nil {
 			assert.NilError(t, err)
 		} else {

e2e/container/attach_test.go

@@ -32,7 +32,7 @@ func withStdinNewline(cmd *icmd.Cmd) {
 
 // Regression test for https://github.com/docker/cli/issues/5294
 func TestAttachInterrupt(t *testing.T) {
-	result := icmd.RunCommand("docker", "run", "-d", fixtures.AlpineImage, "sh", "-c", "sleep 5")
+	result := icmd.RunCommand("docker", "run", "-d", fixtures.AlpineImage, "sh", "-c", "while true; do sleep 1; done")
 	result.Assert(t, icmd.Success)
 	containerID := strings.TrimSpace(result.Stdout())
 
@@ -49,6 +49,6 @@ func TestAttachInterrupt(t *testing.T) {
 	c.Process.Signal(os.Interrupt)
 
 	_ = c.Wait()
-	assert.Equal(t, c.ProcessState.ExitCode(), 0)
-	assert.Equal(t, d.String(), "")
+	assert.Equal(t, c.ProcessState.ExitCode(), 130)
+	assert.Equal(t, d.String(), "exit status 130\n")
 }