Reimplement migrate-if-needed.sh in go

cluster/images/etcd/migrate/data_dir_test.go

@@ -0,0 +1,159 @@
+/*
+Copyright 2018 The Kubernetes 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 main
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/blang/semver"
+)
+
+var (
+	latestVersion = semver.MustParse("3.1.12")
+)
+
+func TestExistingDataDirWithVersionFile(t *testing.T) {
+	d, err := OpenOrCreateDataDirectory("testdata/datadir_with_version")
+	if err != nil {
+		t.Fatalf("Failed to open data dir: %v", err)
+	}
+	isEmpty, err := d.IsEmpty()
+	if err != nil {
+		t.Fatalf("Failed to check if data dir is empty: %v", err)
+	}
+	if isEmpty {
+		t.Errorf("Data directory is non-empty")
+	}
+	exists, err := d.versionFile.Exists()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !exists {
+		t.Fatalf("Expected version file %s to exist", d.versionFile.path)
+	}
+	vp, err := d.versionFile.Read()
+	if err != nil {
+		t.Fatalf("Failed to read version file %s: %v", d.versionFile.path, err)
+	}
+	expectedVersion := &EtcdVersionPair{&EtcdVersion{latestVersion}, storageEtcd3}
+	if !vp.Equals(expectedVersion) {
+		t.Errorf("Expected version file to contain %s, but got %s", expectedVersion, vp)
+	}
+}
+
+func TestExistingDataDirWithoutVersionFile(t *testing.T) {
+	targetVersion := &EtcdVersionPair{&EtcdVersion{latestVersion}, storageEtcd3}
+
+	d, err := OpenOrCreateDataDirectory("testdata/datadir_without_version")
+	if err != nil {
+		t.Fatalf("Failed to open data dir: %v", err)
+	}
+	exists, err := d.versionFile.Exists()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if exists {
+		t.Errorf("Expected version file %s not to exist", d.versionFile.path)
+	}
+	err = d.Initialize(targetVersion)
+	if err != nil {
+		t.Fatalf("Failed initialize data directory %s: %v", d.path, err)
+	}
+	exists, err = d.versionFile.Exists()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if exists {
+		t.Fatalf("Expected version file %s not to exist after initializing non-empty data-dir", d.versionFile.path)
+	}
+}
+
+func TestNonexistingDataDir(t *testing.T) {
+	targetVersion := &EtcdVersionPair{&EtcdVersion{latestVersion}, storageEtcd3}
+	path := newTestPath(t)
+	d, err := OpenOrCreateDataDirectory(filepath.Join(path, "data-dir"))
+	if err != nil {
+		t.Fatalf("Failed to open data dir: %v", err)
+	}
+	isEmpty, err := d.IsEmpty()
+	if err != nil {
+		t.Fatalf("Failed to check if data dir is empty: %v", err)
+	}
+	if !isEmpty {
+		t.Errorf("Data directory is empty")
+	}
+	err = d.Initialize(targetVersion)
+	if err != nil {
+		t.Fatalf("Failed initialize data directory %s: %v", d.path, err)
+	}
+	exists, err := d.versionFile.Exists()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !exists {
+		t.Fatalf("Expected version file %s to exist", d.versionFile.path)
+	}
+	isEmpty, err = d.IsEmpty()
+	if err != nil {
+		t.Fatalf("Failed to check if data dir is empty: %v", err)
+	}
+	if isEmpty {
+		t.Errorf("Data directory is non-empty")
+	}
+	vp, err := d.versionFile.Read()
+	if err != nil {
+		t.Fatalf("Failed to read version file %s: %v", d.versionFile.path, err)
+	}
+	if !vp.Equals(targetVersion) {
+		t.Errorf("Expected version file to contain %s, but got %s", targetVersion, vp)
+	}
+}
+
+func TestBackup(t *testing.T) {
+	path := newTestPath(t)
+	d, err := OpenOrCreateDataDirectory(filepath.Join(path, "data-dir"))
+	if err != nil {
+		t.Fatalf("Failed to open data dir: %v", err)
+	}
+	err = d.Backup()
+	if err != nil {
+		t.Fatalf("Failed to backup data directory %s: %v", d.path, err)
+	}
+	bak, err := OpenOrCreateDataDirectory(filepath.Join(path, "data-dir.bak"))
+	if err != nil {
+		t.Fatalf("Failed to open backup data dir: %v", err)
+	}
+	isEmpty, err := bak.IsEmpty()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if isEmpty {
+		t.Errorf("Expected non-empty backup directory afer Backup()")
+	}
+}
+
+func newTestPath(t *testing.T) string {
+	path, err := ioutil.TempDir("", "etcd-migrate-test-")
+	os.Chmod(path, 0777)
+	if err != nil {
+		t.Fatalf("Failed to create tmp dir for test: %v", err)
+	}
+	return path
+}