Migrate container diff tests in integration-cli to api tests.

This fix migreates container diff tests in integration-cli
to api tests.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

integration/container/diff_test.go

@@ -0,0 +1,98 @@
+package container // import "github.com/docker/docker/integration/container"
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	containertypes "github.com/docker/docker/api/types/container"
+	"github.com/docker/docker/integration/internal/container"
+	"github.com/docker/docker/integration/internal/request"
+	"github.com/docker/docker/pkg/archive"
+	"github.com/gotestyourself/gotestyourself/poll"
+	"github.com/gotestyourself/gotestyourself/skip"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// ensure that an added file shows up in docker diff
+func TestDiffFilenameShownInOutput(t *testing.T) {
+	defer setupTest(t)()
+	client := request.NewAPIClient(t)
+	ctx := context.Background()
+
+	cID := container.Run(t, ctx, client, container.WithCmd("sh", "-c", `mkdir /foo; echo xyzzy > /foo/bar`))
+
+	// Wait for it to exit as cannot diff a running container on Windows, and
+	// it will take a few seconds to exit. Also there's no way in Windows to
+	// differentiate between an Add or a Modify, and all files are under
+	// a "Files/" prefix.
+	lookingFor := containertypes.ContainerChangeResponseItem{Kind: archive.ChangeAdd, Path: "/foo/bar"}
+	if testEnv.OSType == "windows" {
+		poll.WaitOn(t, containerIsInState(ctx, client, cID, "exited"), poll.WithDelay(100*time.Millisecond), poll.WithTimeout(60*time.Second))
+		lookingFor = containertypes.ContainerChangeResponseItem{Kind: archive.ChangeModify, Path: "Files/foo/bar"}
+	}
+
+	items, err := client.ContainerDiff(ctx, cID)
+	require.NoError(t, err)
+	assert.Contains(t, items, lookingFor)
+}
+
+// test to ensure GH #3840 doesn't occur any more
+func TestDiffEnsureInitLayerFilesAreIgnored(t *testing.T) {
+	skip.If(t, testEnv.DaemonInfo.OSType != "linux")
+
+	defer setupTest(t)()
+	client := request.NewAPIClient(t)
+	ctx := context.Background()
+
+	// this is a list of files which shouldn't show up in `docker diff`
+	initLayerFiles := []string{"/etc/resolv.conf", "/etc/hostname", "/etc/hosts", "/.dockerenv"}
+	containerCount := 5
+
+	// we might not run into this problem from the first run, so start a few containers
+	for i := 0; i < containerCount; i++ {
+		cID := container.Run(t, ctx, client, container.WithCmd("sh", "-c", `echo foo > /root/bar`))
+
+		items, err := client.ContainerDiff(ctx, cID)
+		require.NoError(t, err)
+		for _, item := range items {
+			assert.NotContains(t, initLayerFiles, item.Path)
+		}
+	}
+}
+
+func TestDiffEnsureDefaultDevs(t *testing.T) {
+	skip.If(t, testEnv.DaemonInfo.OSType != "linux")
+
+	defer setupTest(t)()
+	client := request.NewAPIClient(t)
+	ctx := context.Background()
+
+	cID := container.Run(t, ctx, client, container.WithCmd("sleep", "0"))
+
+	items, err := client.ContainerDiff(ctx, cID)
+	require.NoError(t, err)
+
+	expected := []containertypes.ContainerChangeResponseItem{
+		{Kind: archive.ChangeModify, Path: "/dev"},
+		{Kind: archive.ChangeAdd, Path: "/dev/full"},    // busybox
+		{Kind: archive.ChangeModify, Path: "/dev/ptmx"}, // libcontainer
+		{Kind: archive.ChangeAdd, Path: "/dev/mqueue"},
+		{Kind: archive.ChangeAdd, Path: "/dev/kmsg"},
+		{Kind: archive.ChangeAdd, Path: "/dev/fd"},
+		{Kind: archive.ChangeAdd, Path: "/dev/ptmx"},
+		{Kind: archive.ChangeAdd, Path: "/dev/null"},
+		{Kind: archive.ChangeAdd, Path: "/dev/random"},
+		{Kind: archive.ChangeAdd, Path: "/dev/stdout"},
+		{Kind: archive.ChangeAdd, Path: "/dev/stderr"},
+		{Kind: archive.ChangeAdd, Path: "/dev/tty1"},
+		{Kind: archive.ChangeAdd, Path: "/dev/stdin"},
+		{Kind: archive.ChangeAdd, Path: "/dev/tty"},
+		{Kind: archive.ChangeAdd, Path: "/dev/urandom"},
+	}
+
+	for _, item := range items {
+		assert.Contains(t, expected, item)
+	}
+}