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>
(cherry picked from commit 7b46bfc)
Signed-off-by: Laura Brehm <laurabrehm@hey.com>

Author: laurazard

cli/command/container/attach.go

@@ -73,7 +73,8 @@ 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 {

cli/command/container/attach_test.go

@@ -81,11 +81,7 @@ 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
@@ -116,13 +112,17 @@ func TestGetExitStatus(t *testing.T) {
 	}
 
 	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

@@ -1,12 +1,19 @@
 package container
 
 import (
+	"bytes"
 	"fmt"
+	"os"
+	"os/exec"
 	"strings"
 	"testing"
+	"time"
 
+	"github.com/creack/pty"
 	"github.com/docker/cli/e2e/internal/fixtures"
+	"gotest.tools/v3/assert"
 	"gotest.tools/v3/icmd"
+	"gotest.tools/v3/skip"
 )
 
 func TestAttachExitCode(t *testing.T) {
@@ -23,3 +30,34 @@ func TestAttachExitCode(t *testing.T) {
 func withStdinNewline(cmd *icmd.Cmd) {
 	cmd.Stdin = strings.NewReader("\n")
 }
+
+// Regression test for https://github.com/docker/cli/issues/5294
+func TestAttachInterrupt(t *testing.T) {
+	// this is a new test, it already did not work (inside dind) when over ssh
+	// todo(laurazard): make this test work w/ dind over ssh
+	skip.If(t, strings.Contains(os.Getenv("DOCKER_HOST"), "ssh://"))
+
+	// if
+	result := icmd.RunCommand("docker", "run", "-d", fixtures.AlpineImage,
+		"sh", "-c", "trap \"exit 33\" SIGINT; for i in $(seq 100); do sleep 0.1; done; exit 34")
+	result.Assert(t, icmd.Success)
+	containerID := strings.TrimSpace(result.Stdout())
+
+	// run it as such so we can signal it later
+	c := exec.Command("docker", "attach", containerID)
+	d := bytes.Buffer{}
+	c.Stdout = &d
+	c.Stderr = &d
+	_, err := pty.Start(c)
+	assert.NilError(t, err)
+
+	// have to wait a bit to give time for the command to execute/print
+	time.Sleep(500 * time.Millisecond)
+	c.Process.Signal(os.Interrupt)
+
+	_ = c.Wait()
+	// the CLI should exit with 33 (the SIGINT was forwarded to the container), and the
+	// CLI process waited for the container exit and properly captured/set the exit code
+	assert.Equal(t, c.ProcessState.ExitCode(), 33)
+	assert.Equal(t, d.String(), "exit status 33\n")
+}