Fix ExecContainer executing commands twice

test/docker/docker_api_test.go

@@ -329,9 +329,9 @@ func TestVolumeUnmount(t *testing.T) {
 	defer cleanContainer(t, cli, ctr.ID)
 	waitForReady(t, cli, ctr.ID)
 	// Unmount the volume as root
-	rc, _ := execContainer(t, cli, ctr.ID, "root", []string{"umount", "-l", "-f", "/mnt/mqm"})
+	rc, out := execContainer(t, cli, ctr.ID, "root", []string{"umount", "-l", "-f", "/mnt/mqm"})
 	if rc != 0 {
-		t.Fatalf("Expected umount to work with rc=0, got %v", rc)
+		t.Fatalf("Expected umount to work with rc=0, got %v. Output was: %s", rc, out)
 	}
 	time.Sleep(3 * time.Second)
 	rc, _ = execContainer(t, cli, ctr.ID, "mqm", []string{"chkmqhealthy"})
@@ -366,7 +366,9 @@ func TestZombies(t *testing.T) {
 	// will be adopted by PID 1, and should then be reaped when they die.
 	_, out := execContainer(t, cli, id, "mqm", []string{"pkill", "--signal", "kill", "-c", "amqzxma0"})
 	if out == "0" {
-		t.Fatalf("Expected pkill to kill a process, got %v", out)
+		t.Log("Failed to kill process 'amqzxma0'")
+		_, out := execContainer(t, cli, id, "root", []string{"ps", "-lA"})
+		t.Fatalf("Here is a list of currently running processes:\n%s", out)
 	}
 	time.Sleep(3 * time.Second)
 	_, out = execContainer(t, cli, id, "mqm", []string{"bash", "-c", "ps -lA | grep '^. Z'"})

test/docker/docker_api_test_util.go

@@ -328,7 +328,6 @@ func waitForContainer(t *testing.T, cli *client.Client, ID string, timeout int64
 
 // execContainer runs a command in a running container, and returns the exit code and output
 func execContainer(t *testing.T, cli *client.Client, ID string, user string, cmd []string) (int, string) {
-rerun:
 	config := types.ExecConfig{
 		User:        user,
 		Privileged:  false,
@@ -357,30 +356,33 @@ rerun:
 	}
 	// Wait for the command to finish
 	var exitcode int
+	var outputStr string
 	for {
 		inspect, err := cli.ContainerExecInspect(context.Background(), resp.ID)
 		if err != nil {
 			t.Fatal(err)
 		}
-		if !inspect.Running {
-			exitcode = inspect.ExitCode
-			break
+		if inspect.Running {
+			continue
 		}
-	}
-	buf := new(bytes.Buffer)
-	// Each output line has a header, which needs to be removed
-	_, err = stdcopy.StdCopy(buf, buf, hijack.Reader)
-	if err != nil {
-		t.Fatal(err)
-	}
 
-	outputStr := strings.TrimSpace(buf.String())
+		exitcode = inspect.ExitCode
+		buf := new(bytes.Buffer)
+		// Each output line has a header, which needs to be removed
+		_, err = stdcopy.StdCopy(buf, buf, hijack.Reader)
+		if err != nil {
+			t.Fatal(err)
+		}
 
-	// Before we go let's just double check it did actually run because sometimes we get a "Exec command already running error"
-	alreadyRunningErr := regexp.MustCompile("Error: Exec command .* is already running")
-	if alreadyRunningErr.MatchString(outputStr) {
-		time.Sleep(1 * time.Second)
-		goto rerun
+		outputStr = strings.TrimSpace(buf.String())
+
+		// Before we go let's just double check it did actually finish running
+		// because sometimes we get a "Exec command already running error"
+		alreadyRunningErr := regexp.MustCompile("Error: Exec command .* is already running")
+		if alreadyRunningErr.MatchString(outputStr) {
+			continue
+		}
+		break
 	}
 
 	return exitcode, outputStr