func run(cl cluster.Cluster, candidate *leadership.Candidate, server *api.Server, primary *mux.Router, replica *api.Replica) { electedCh, errCh := candidate.RunForElection() var watchdog *cluster.Watchdog for { select { case isElected := <-electedCh: if isElected { log.Info("Leader Election: Cluster leadership acquired") watchdog = cluster.NewWatchdog(cl) server.SetHandler(primary) } else { log.Info("Leader Election: Cluster leadership lost") cl.UnregisterEventHandler(watchdog) server.SetHandler(replica) } case err := <-errCh: log.Error(err) return } } }
func manage(c *cli.Context) { var ( tlsConfig *tls.Config err error ) // If either --tls or --tlsverify are specified, load the certificates. if c.Bool("tls") || c.Bool("tlsverify") { if !c.IsSet("tlscert") || !c.IsSet("tlskey") { log.Fatal("--tlscert and --tlskey must be provided when using --tls") } if c.Bool("tlsverify") && !c.IsSet("tlscacert") { log.Fatal("--tlscacert must be provided when using --tlsverify") } tlsConfig, err = loadTLSConfig( c.String("tlscacert"), c.String("tlscert"), c.String("tlskey"), c.Bool("tlsverify")) if err != nil { log.Fatal(err) } } else { // Otherwise, if neither --tls nor --tlsverify are specified, abort if // the other flags are passed as they will be ignored. if c.IsSet("tlscert") || c.IsSet("tlskey") || c.IsSet("tlscacert") { log.Fatal("--tlscert, --tlskey and --tlscacert require the use of either --tls or --tlsverify") } } refreshMinInterval := c.Duration("engine-refresh-min-interval") refreshMaxInterval := c.Duration("engine-refresh-max-interval") if refreshMinInterval == time.Duration(0)*time.Second { log.Fatal("minimum refresh interval should be a positive number") } if refreshMaxInterval < refreshMinInterval { log.Fatal("max refresh interval cannot be less than min refresh interval") } // engine-refresh-retry is deprecated refreshRetry := c.Int("engine-refresh-retry") if refreshRetry != 3 { log.Fatal("--engine-refresh-retry is deprecated. Use --engine-failure-retry") } failureRetry := c.Int("engine-failure-retry") if failureRetry <= 0 { log.Fatal("invalid failure retry count") } engineOpts := &cluster.EngineOpts{ RefreshMinInterval: refreshMinInterval, RefreshMaxInterval: refreshMaxInterval, FailureRetry: failureRetry, } uri := getDiscovery(c) if uri == "" { log.Fatalf("discovery required to manage a cluster. See '%s manage --help'.", c.App.Name) } discovery := createDiscovery(uri, c, c.StringSlice("discovery-opt")) s, err := strategy.New(c.String("strategy")) if err != nil { log.Fatal(err) } // see https://github.com/codegangsta/cli/issues/160 names := c.StringSlice("filter") if c.IsSet("filter") || c.IsSet("f") { names = names[DefaultFilterNumber:] } fs, err := filter.New(names) if err != nil { log.Fatal(err) } sched := scheduler.New(s, fs) var cl cluster.Cluster switch c.String("cluster-driver") { case "mesos-experimental": log.Warn("WARNING: the mesos driver is currently experimental, use at your own risks") cl, err = mesos.NewCluster(sched, tlsConfig, uri, c.StringSlice("cluster-opt"), engineOpts) case "swarm": cl, err = swarm.NewCluster(sched, tlsConfig, discovery, c.StringSlice("cluster-opt"), engineOpts) default: log.Fatalf("unsupported cluster %q", c.String("cluster-driver")) } if err != nil { log.Fatal(err) } // see https://github.com/codegangsta/cli/issues/160 hosts := c.StringSlice("host") if c.IsSet("host") || c.IsSet("H") { hosts = hosts[1:] } server := api.NewServer(hosts, tlsConfig) if c.Bool("replication") { addr := c.String("advertise") if addr == "" { log.Fatal("--advertise address must be provided when using --leader-election") } if !checkAddrFormat(addr) { log.Fatal("--advertise should be of the form ip:port or hostname:port") } leaderTTL, err := time.ParseDuration(c.String("replication-ttl")) if err != nil { log.Fatalf("invalid --replication-ttl: %v", err) } setupReplication(c, cl, server, discovery, addr, leaderTTL, tlsConfig) } else { server.SetHandler(api.NewPrimary(cl, tlsConfig, &statusHandler{cl, nil, nil}, c.GlobalBool("debug"), c.Bool("cors"))) } if experimental.ENABLED { log.Warn("WARNING: rescheduling is currently experimental, use at your own risks") cluster.NewWatchdog(cl) } log.Fatal(server.ListenAndServe()) }