Add integ test to check tty leak

Signed-off-by: Henry Wang <henwang@amazon.com>

integration/container_tty_leak_linux_test.go

@@ -0,0 +1,144 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package integration
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net/url"
+	"os/exec"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/containerd/containerd/v2/integration/images"
+	"github.com/containerd/containerd/v2/pkg/namespaces"
+	"github.com/stretchr/testify/require"
+	"k8s.io/client-go/rest"
+	remoteclient "k8s.io/client-go/tools/remotecommand"
+	criruntime "k8s.io/cri-api/pkg/apis/runtime/v1"
+)
+
+func TestContainerTTYLeakAfterExit(t *testing.T) {
+	t.Log("Create a sandbox")
+	sb, sbConfig := PodSandboxConfigWithCleanup(t, "sandbox", "container-tty-leak-after-exit")
+
+	testImage := images.Get(images.BusyBox)
+	EnsureImageExists(t, testImage)
+
+	var testcases = []struct {
+		name  string
+		stdin bool
+	}{
+		{
+			name:  "ttyOnly",
+			stdin: false,
+		},
+		{
+			name:  "interactive",
+			stdin: true,
+		},
+	}
+
+	for _, testcase := range testcases {
+		t.Run(testcase.name, func(t *testing.T) {
+			t.Log("Create a container")
+			cnConfig := ContainerConfig(
+				testcase.name,
+				testImage,
+				WithCommand("sh", "-c", "sleep 365d"),
+			)
+			cnConfig.Stdin = testcase.stdin
+			cnConfig.Tty = true
+
+			t.Log("Create the container")
+			cn, err := runtimeService.CreateContainer(sb, cnConfig, sbConfig)
+			require.NoError(t, err)
+
+			t.Log("Start the container")
+			require.NoError(t, runtimeService.StartContainer(cn))
+
+			pid := getShimPid(t, sb)
+			checkTTY(t, pid, 1)
+
+			t.Log("Exec in container")
+			rsp, err := runtimeService.Exec(&criruntime.ExecRequest{
+				ContainerId: cn,
+				Cmd:         []string{"sh", "-c", "echo tty"},
+				Stderr:      false,
+				Stdout:      true,
+				Stdin:       testcase.stdin,
+				Tty:         true,
+			})
+			require.NoError(t, err)
+
+			execURL := rsp.Url
+			URL, err := url.Parse(execURL)
+			require.NoError(t, err)
+
+			executor, err := remoteclient.NewSPDYExecutor(&rest.Config{}, "POST", URL)
+			require.NoError(t, err)
+
+			outBuf := bytes.NewBuffer(make([]byte, 64))
+			streamOptions := remoteclient.StreamOptions{
+				Stdout: outBuf,
+				Tty:    true,
+			}
+			if testcase.stdin {
+				streamOptions.Stdin = bytes.NewBuffer(nil)
+			}
+
+			require.NoError(t, executor.StreamWithContext(context.Background(), streamOptions))
+			checkTTY(t, pid, 1)
+
+			t.Log("Stop the container")
+			require.NoError(t, runtimeService.StopContainer(cn, 10))
+
+			t.Log("Remove the container")
+			require.NoError(t, runtimeService.RemoveContainer(cn))
+
+			checkTTY(t, pid, 0)
+		})
+	}
+
+}
+
+func getShimPid(t *testing.T, sb string) int {
+	ctx := namespaces.WithNamespace(context.Background(), "k8s.io")
+	shimCli := connectToShim(ctx, t, containerdEndpoint, 3, sb)
+	return int(shimPid(ctx, t, shimCli))
+}
+
+func numTTY(shimPid int) int {
+	cmd := exec.Command("sh", "-c", fmt.Sprintf("lsof -p %d | grep ptmx", shimPid))
+	var stdout bytes.Buffer
+	cmd.Stdout = &stdout
+	if err := cmd.Run(); err != nil {
+		return 0
+	}
+	return strings.Count(stdout.String(), "\n")
+}
+
+func checkTTY(t *testing.T, shimPid, expected int) {
+	require.NoError(t, Eventually(func() (bool, error) {
+		if numTTY(shimPid) == expected {
+			return true, nil
+		}
+		return false, nil
+	}, time.Second, 30*time.Second))
+}