pkg/storagemigration: add integration test

Signed-off-by: Robert Günzler <robertg@balena.io>

integration/storagemigration/aufs_to_overlay2_test.go

@@ -0,0 +1,81 @@
+package storagemigration
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/container"
+
+	"github.com/docker/docker/internal/test/daemon"
+
+	"gotest.tools/assert"
+	"gotest.tools/fs"
+	"gotest.tools/skip"
+)
+
+func TestAufsToOverlay2Migration(t *testing.T) {
+	skip.If(t, testEnv.DaemonInfo.OSType != "linux")
+	skip.If(t, testEnv.DaemonInfo.Driver != "overlay2")
+	defer setupTest(t)()
+
+	var err error
+
+	root := fs.NewDir(t, t.Name())
+	defer root.Remove()
+
+	{
+		// aufs.tar.gz contains a snapshot of /var/lib/docker after
+		// building testdata/Dockerfile using dockerd which uses aufs
+		// as default storage driver
+		tar := exec.Command("tar", "-xzf", filepath.Join("testdata", "aufs.tar.gz"), "-C", root.Path())
+		tar.Stdout = os.Stdout
+		tar.Stderr = os.Stderr
+		assert.NilError(t, tar.Run())
+	}
+
+	// if testing.Verbose() {
+	// 	logrus.SetLevel(logrus.DebugLevel)
+	// }
+	// err = storagemigration.Migrate(root.Path())
+	// assert.NilError(t, err)
+
+	err = os.Setenv("BALENA_MIGRATE_OVERLAY", "1")
+	assert.NilError(t, err)
+
+	d := daemon.New(t)
+	d.Root = root.Path()
+	d.Start(t)
+	defer d.Stop(t)
+
+	ctx := context.Background()
+
+	cl := d.NewClientT(t)
+
+	ctr, err := cl.ContainerCreate(ctx,
+		&container.Config{
+			Image: "a2o-test",
+		},
+		nil,
+		nil,
+		"",
+	)
+	assert.NilError(t, err)
+
+	err = cl.ContainerStart(ctx, ctr.ID, types.ContainerStartOptions{})
+	assert.NilError(t, err)
+
+	// original f1 should be removed (.wh.)
+	_, err = cl.ContainerStatPath(ctx, ctr.ID, "/tmp/f1")
+	assert.ErrorContains(t, err, "No such container:path")
+	// original d1 should be opaque (.wh..wh.opq)
+	_, err = cl.ContainerStatPath(ctx, ctr.ID, "/tmp/d1/d1f2")
+	assert.NilError(t, err)
+	_, err = cl.ContainerStatPath(ctx, ctr.ID, "/tmp/hlkn")
+	assert.NilError(t, err)
+	_, err = cl.ContainerStatPath(ctx, ctr.ID, "/tmp/slkn")
+	assert.NilError(t, err)
+}

integration/storagemigration/main_test.go

@@ -0,0 +1,33 @@
+package storagemigration
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/docker/docker/internal/test/environment"
+)
+
+var testEnv *environment.Execution
+
+func TestMain(m *testing.M) {
+	var err error
+	testEnv, err = environment.New()
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	err = environment.EnsureFrozenImagesLinux(testEnv)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	testEnv.Print()
+	os.Exit(m.Run())
+}
+
+func setupTest(t *testing.T) func() {
+	environment.ProtectAll(t, testEnv)
+	return func() { testEnv.Clean(t) }
+}

integration/storagemigration/testdata/Dockerfile

@@ -0,0 +1,5 @@
+FROM busybox:1.33.0
+RUN mkdir /tmp/d1 && touch /tmp/d1/d1f1 && touch /tmp/f1 && touch /tmp/f2
+RUN rm -R /tmp/d1 && mkdir /tmp/d1 && touch /tmp/d1/d1f2 && rm /tmp/f1
+RUN ln -s /tmp/d1/d1f2 /tmp/slkn
+RUN ln /tmp/d1/d1f2 /tmp/hlkn