add redis lock, it will be used to lock digest in the quota scenario

Signed-off-by: wang yan <wangyan@vmware.com>

src/common/utils/redis/helper.go

@@ -0,0 +1,114 @@
+// Copyright Project Harbor 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 redis
+
+import (
+	"errors"
+	"github.com/garyburd/redigo/redis"
+	"github.com/goharbor/harbor/src/common/utils"
+	"time"
+)
+
+var (
+	// ErrUnLock ...
+	ErrUnLock = errors.New("error to release the redis lock")
+)
+
+const (
+	unlockScript = `
+if redis.call("get",KEYS[1]) == ARGV[1] then
+    return redis.call("del",KEYS[1])
+else
+    return 0
+end
+`
+	defaultDelay    = 5 * time.Second
+	defaultMaxRetry = 5
+	defaultExpiry   = 600 * time.Second
+)
+
+// Mutex ...
+type Mutex struct {
+	Conn  redis.Conn
+	key   string
+	value string
+	opts  Options
+}
+
+// New ...
+func New(conn redis.Conn, key, value string) *Mutex {
+	o := *DefaultOptions()
+	if value == "" {
+		value = utils.GenerateRandomString()
+	}
+	return &Mutex{conn, key, value, o}
+}
+
+// Require retry to require the lock
+func (rm *Mutex) Require() (bool, error) {
+	var isRequired bool
+	var err error
+
+	for i := 0; i < rm.opts.maxRetry; i++ {
+		isRequired, err = rm.require()
+		if isRequired {
+			break
+		}
+		if err != nil || !isRequired {
+			time.Sleep(rm.opts.retryDelay)
+		}
+	}
+
+	return isRequired, err
+}
+
+// require get the redis lock, for details, just refer to https://redis.io/topics/distlock
+func (rm *Mutex) require() (bool, error) {
+	reply, err := redis.String(rm.Conn.Do("SET", rm.key, rm.value, "NX", "PX", int(rm.opts.expiry/time.Millisecond)))
+	if err != nil {
+		return false, err
+	}
+	return reply == "OK", nil
+}
+
+// Free releases the lock, for details, just refer to https://redis.io/topics/distlock
+func (rm *Mutex) Free() (bool, error) {
+	script := redis.NewScript(1, unlockScript)
+	resp, err := redis.Int(script.Do(rm.Conn, rm.key, rm.value))
+	if err != nil {
+		return false, err
+	}
+	if resp == 0 {
+		return false, ErrUnLock
+	}
+	return true, nil
+}
+
+// Options ...
+type Options struct {
+	retryDelay time.Duration
+	expiry     time.Duration
+	maxRetry   int
+}
+
+// DefaultOptions ...
+func DefaultOptions() *Options {
+	opt := &Options{
+		retryDelay: defaultDelay,
+		expiry:     defaultExpiry,
+		maxRetry:   defaultMaxRetry,
+	}
+	return opt
+}

src/common/utils/redis/helper_test.go

@@ -0,0 +1,62 @@
+// Copyright Project Harbor 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 redis
+
+import (
+	"fmt"
+	"github.com/garyburd/redigo/redis"
+	"github.com/stretchr/testify/assert"
+	"os"
+	"testing"
+	"time"
+)
+
+const testingRedisHost = "REDIS_HOST"
+
+func TestRedisLock(t *testing.T) {
+	con, err := redis.Dial(
+		"tcp",
+		fmt.Sprintf("%s:%d", getRedisHost(), 6379),
+		redis.DialConnectTimeout(30*time.Second),
+		redis.DialReadTimeout(time.Minute+10*time.Second),
+		redis.DialWriteTimeout(10*time.Second),
+	)
+	assert.Nil(t, err)
+	defer con.Close()
+
+	rm := New(con, "test-redis-lock", "test-value")
+
+	successLock, err := rm.Require()
+	assert.Nil(t, err)
+	assert.True(t, successLock)
+
+	time.Sleep(2 * time.Second)
+	_, err = rm.Require()
+	assert.NotNil(t, err)
+
+	successUnLock, err := rm.Free()
+	assert.Nil(t, err)
+	assert.True(t, successUnLock)
+
+}
+
+func getRedisHost() string {
+	redisHost := os.Getenv(testingRedisHost)
+	if redisHost == "" {
+		redisHost = "127.0.0.1" // for local test
+	}
+
+	return redisHost
+}