package agent import ( "fmt" "log" "strings" "time" discover "github.com/hashicorp/go-discover" ) func (a *Agent) retryJoinLAN() { r := &retryJoiner{ cluster: "LAN", addrs: a.config.RetryJoinLAN, maxAttempts: a.config.RetryJoinMaxAttemptsLAN, interval: a.config.RetryJoinIntervalLAN, join: a.JoinLAN, logger: a.logger, } if err := r.retryJoin(); err != nil { a.retryJoinCh <- err } } func (a *Agent) retryJoinWAN() { r := &retryJoiner{ cluster: "WAN", addrs: a.config.RetryJoinWAN, maxAttempts: a.config.RetryJoinMaxAttemptsWAN, interval: a.config.RetryJoinIntervalWAN, join: a.JoinWAN, logger: a.logger, } if err := r.retryJoin(); err != nil { a.retryJoinCh <- err } } // retryJoiner is used to handle retrying a join until it succeeds or all // retries are exhausted. type retryJoiner struct { // cluster is the name of the serf cluster, e.g. "LAN" or "WAN". cluster string // addrs is the list of servers or go-discover configurations // to join with. addrs []string // maxAttempts is the number of join attempts before giving up. maxAttempts int // interval is the time between two join attempts. interval time.Duration // join adds the discovered or configured servers to the given // serf cluster. join func([]string) (int, error) // logger is the agent logger. Log messages should contain the // "agent: " prefix. logger *log.Logger } func (r *retryJoiner) retryJoin() error { if len(r.addrs) == 0 { return nil } disco := discover.Discover{} r.logger.Printf("[INFO] agent: Retry join %s is supported for: %s", r.cluster, strings.Join(disco.Names(), " ")) r.logger.Printf("[INFO] agent: Joining %s cluster...", r.cluster) attempt := 0 for { var addrs []string var err error for _, addr := range r.addrs { switch { case strings.Contains(addr, "provider="): servers, err := disco.Addrs(addr, r.logger) if err != nil { r.logger.Printf("[ERR] agent: Join %s: %s", r.cluster, err) } else { addrs = append(addrs, servers...) r.logger.Printf("[INFO] agent: Discovered %s servers: %s", r.cluster, strings.Join(servers, " ")) } default: addrs = append(addrs, addr) } } if len(addrs) > 0 { n, err := r.join(addrs) if err == nil { r.logger.Printf("[INFO] agent: Join %s completed. Synced with %d initial agents", r.cluster, n) return nil } } if len(addrs) == 0 { err = fmt.Errorf("No servers to join") } attempt++ if r.maxAttempts > 0 && attempt > r.maxAttempts { return fmt.Errorf("agent: max join %s retry exhausted, exiting", r.cluster) } r.logger.Printf("[WARN] agent: Join %s failed: %v, retrying in %v", r.cluster, err, r.interval) time.Sleep(r.interval) } }