Golang Client.LockOpts方法代碼示例

// setupLock is used to setup a new Lock given the API client, the key prefix to
// operate on, and an optional session name. If oneshot is true then we will set
// up for a single attempt at acquisition, using the given wait time. The retry
// parameter sets how many 500 errors the lock monitor will tolerate before
// giving up the lock.
func (c *LockCommand) setupLock(client *api.Client, prefix, name string,
	oneshot bool, wait time.Duration, retry int) (*LockUnlock, error) {
	// Use the DefaultSemaphoreKey extension, this way if a lock and
	// semaphore are both used at the same prefix, we will get a conflict
	// which we can report to the user.
	key := path.Join(prefix, api.DefaultSemaphoreKey)
	if c.verbose {
		c.Ui.Info(fmt.Sprintf("Setting up lock at path: %s", key))
	}
	opts := api.LockOptions{
		Key:              key,
		SessionName:      name,
		MonitorRetries:   retry,
		MonitorRetryTime: defaultMonitorRetryTime,
	}
	if oneshot {
		opts.LockTryOnce = true
		opts.LockWaitTime = wait
	}
	l, err := client.LockOpts(&opts)
	if err != nil {
		return nil, err
	}
	lu := &LockUnlock{
		lockFn:    l.Lock,
		unlockFn:  l.Unlock,
		cleanupFn: l.Destroy,
		inUseErr:  api.ErrLockInUse,
		rawOpts:   &opts,
	}
	return lu, nil
}

func (d *DedupManager) attemptLock(client *consulapi.Client, session string, sessionCh chan struct{}, t *Template) {
	defer d.wg.Done()
START:
	log.Printf("[INFO] (dedup) attempting lock for template hash %s", t.hexMD5)
	basePath := path.Join(d.config.Deduplicate.Prefix, t.hexMD5)
	lopts := &consulapi.LockOptions{
		Key:              path.Join(basePath, "lock"),
		Session:          session,
		MonitorRetries:   3,
		MonitorRetryTime: 3 * time.Second,
	}
	lock, err := client.LockOpts(lopts)
	if err != nil {
		log.Printf("[ERR] (dedup) failed to create lock '%s': %v",
			lopts.Key, err)
		return
	}

	var retryCh <-chan time.Time
	leaderCh, err := lock.Lock(sessionCh)
	if err != nil {
		log.Printf("[ERR] (dedup) failed to acquire lock '%s': %v",
			lopts.Key, err)
		retryCh = time.After(lockRetry)
	} else {
		log.Printf("[INFO] (dedup) acquired lock '%s'", lopts.Key)
		d.setLeader(t, leaderCh)
	}

	select {
	case <-retryCh:
		retryCh = nil
		goto START
	case <-leaderCh:
		log.Printf("[WARN] (dedup) lost lock ownership '%s'", lopts.Key)
		d.setLeader(t, nil)
		goto START
	case <-sessionCh:
		log.Printf("[INFO] (dedup) releasing lock '%s'", lopts.Key)
		d.setLeader(t, nil)
		lock.Unlock()
	case <-d.stopCh:
		log.Printf("[INFO] (dedup) releasing lock '%s'", lopts.Key)
		lock.Unlock()
	}
}

// setupLock is used to setup a new Lock given the API client,
// the key prefix to operate on, and an optional session name.
func (c *LockCommand) setupLock(client *api.Client, prefix, name string) (*LockUnlock, error) {
	// Use the DefaultSemaphoreKey extension, this way if a lock and
	// semaphore are both used at the same prefix, we will get a conflict
	// which we can report to the user.
	key := path.Join(prefix, api.DefaultSemaphoreKey)
	if c.verbose {
		c.Ui.Info(fmt.Sprintf("Setting up lock at path: %s", key))
	}
	opts := api.LockOptions{
		Key:         key,
		SessionName: name,
	}
	l, err := client.LockOpts(&opts)
	if err != nil {
		return nil, err
	}
	lu := &LockUnlock{
		lockFn:    l.Lock,
		unlockFn:  l.Unlock,
		cleanupFn: l.Destroy,
		inUseErr:  api.ErrLockInUse,
	}
	return lu, nil
}