package agent import ( "context" "flag" "fmt" "io/ioutil" "os" "os/signal" "path/filepath" "strings" "syscall" "time" "github.com/hashicorp/go-checkpoint" "github.com/hashicorp/go-hclog" mcli "github.com/mitchellh/cli" "github.com/hashicorp/consul/agent" "github.com/hashicorp/consul/agent/config" "github.com/hashicorp/consul/command/cli" "github.com/hashicorp/consul/command/flags" "github.com/hashicorp/consul/lib" "github.com/hashicorp/consul/logging" "github.com/hashicorp/consul/service_os" consulversion "github.com/hashicorp/consul/version" ) func New(ui cli.Ui) *cmd { c := &cmd{ ui: ui, revision: consulversion.GitCommit, version: consulversion.Version, versionPrerelease: consulversion.VersionPrerelease, versionHuman: consulversion.GetHumanVersion(), flags: flag.NewFlagSet("", flag.ContinueOnError), } c.init() return c } // AgentCommand is a Command implementation that runs a Consul agent. // The command will not end unless a shutdown message is sent on the // ShutdownCh. If two messages are sent on the ShutdownCh it will forcibly // exit. type cmd struct { ui cli.Ui flags *flag.FlagSet http *flags.HTTPFlags help string revision string version string versionPrerelease string versionHuman string flagArgs config.BuilderOpts logger hclog.InterceptLogger } func (c *cmd) init() { c.flags = flag.NewFlagSet("", flag.ContinueOnError) config.AddFlags(c.flags, &c.flagArgs) c.help = flags.Usage(help, c.flags) } func (c *cmd) Run(args []string) int { code := c.run(args) if c.logger != nil { c.logger.Info("Exit code", "code", code) } return code } // checkpointResults is used to handler periodic results from our update checker func (c *cmd) checkpointResults(results *checkpoint.CheckResponse, err error) { if err != nil { c.logger.Error("Failed to check for updates", "error", err) return } if results.Outdated { c.logger.Info("Newer Consul version available", "new_version", results.CurrentVersion, "current_version", c.version) } for _, alert := range results.Alerts { switch alert.Level { case "info": c.logger.Info("Bulletin", "alert_level", alert.Level, "alert_message", alert.Message, "alert_URL", alert.URL) default: c.logger.Error("Bulletin", "alert_level", alert.Level, "alert_message", alert.Message, "alert_URL", alert.URL) } } } func (c *cmd) startupUpdateCheck(config *config.RuntimeConfig) { version := config.Version if config.VersionPrerelease != "" { version += fmt.Sprintf("-%s", config.VersionPrerelease) } updateParams := &checkpoint.CheckParams{ Product: "consul", Version: version, } if !config.DisableAnonymousSignature { updateParams.SignatureFile = filepath.Join(config.DataDir, "checkpoint-signature") } // Schedule a periodic check with expected interval of 24 hours checkpoint.CheckInterval(updateParams, 24*time.Hour, c.checkpointResults) // Do an immediate check within the next 30 seconds go func() { time.Sleep(lib.RandomStagger(30 * time.Second)) c.checkpointResults(checkpoint.Check(updateParams)) }() } // startupJoin is invoked to handle any joins specified to take place at start time func (c *cmd) startupJoin(agent *agent.Agent, cfg *config.RuntimeConfig) error { if len(cfg.StartJoinAddrsLAN) == 0 { return nil } c.logger.Info("Joining cluster") n, err := agent.JoinLAN(cfg.StartJoinAddrsLAN) if err != nil { return err } c.logger.Info("Join completed. Initial agents synced with", "agent_count", n) return nil } // startupJoinWan is invoked to handle any joins -wan specified to take place at start time func (c *cmd) startupJoinWan(agent *agent.Agent, cfg *config.RuntimeConfig) error { if len(cfg.StartJoinAddrsWAN) == 0 { return nil } c.logger.Info("Joining wan cluster") n, err := agent.JoinWAN(cfg.StartJoinAddrsWAN) if err != nil { return err } c.logger.Info("Join wan completed. Initial agents synced with", "agent_count", n) return nil } func (c *cmd) run(args []string) int { ui := &mcli.PrefixedUi{ OutputPrefix: "==> ", InfoPrefix: " ", ErrorPrefix: "==> ", Ui: c.ui, } if err := c.flags.Parse(args); err != nil { if !strings.Contains(err.Error(), "help requested") { ui.Error(fmt.Sprintf("error parsing flags: %v", err)) } return 1 } if len(c.flags.Args()) > 0 { ui.Error(fmt.Sprintf("Unexpected extra arguments: %v", c.flags.Args())) return 1 } // FIXME: logs should always go to stderr, but previously they were sent to // stdout, so continue to use Stdout for now, and fix this in a future release. logGate := &logging.GatedWriter{Writer: c.ui.Stdout()} loader := func(source config.Source) (cfg *config.RuntimeConfig, warnings []string, err error) { return config.Load(c.flagArgs, source) } bd, err := agent.NewBaseDeps(loader, logGate) if err != nil { ui.Error(err.Error()) return 1 } c.logger = bd.Logger agent, err := agent.New(bd) if err != nil { ui.Error(err.Error()) return 1 } config := bd.RuntimeConfig if config.Logging.LogJSON { // Hide all non-error output when JSON logging is enabled. ui.Ui = &cli.BasicUI{ BasicUi: mcli.BasicUi{ErrorWriter: c.ui.Stderr(), Writer: ioutil.Discard}, } } ui.Output("Starting Consul agent...") segment := config.SegmentName if config.ServerMode { segment = "" } ui.Info(fmt.Sprintf(" Version: '%s'", c.versionHuman)) ui.Info(fmt.Sprintf(" Node ID: '%s'", config.NodeID)) ui.Info(fmt.Sprintf(" Node name: '%s'", config.NodeName)) ui.Info(fmt.Sprintf(" Datacenter: '%s' (Segment: '%s')", config.Datacenter, segment)) ui.Info(fmt.Sprintf(" Server: %v (Bootstrap: %v)", config.ServerMode, config.Bootstrap)) ui.Info(fmt.Sprintf(" Client Addr: %v (HTTP: %d, HTTPS: %d, gRPC: %d, DNS: %d)", config.ClientAddrs, config.HTTPPort, config.HTTPSPort, config.GRPCPort, config.DNSPort)) ui.Info(fmt.Sprintf(" Cluster Addr: %v (LAN: %d, WAN: %d)", config.AdvertiseAddrLAN, config.SerfPortLAN, config.SerfPortWAN)) ui.Info(fmt.Sprintf(" Encrypt: Gossip: %v, TLS-Outgoing: %v, TLS-Incoming: %v, Auto-Encrypt-TLS: %t", config.EncryptKey != "", config.VerifyOutgoing, config.VerifyIncoming, config.AutoEncryptTLS || config.AutoEncryptAllowTLS)) // Enable log streaming ui.Output("") ui.Output("Log data will now stream in as it occurs:\n") logGate.Flush() // wait for signal signalCh := make(chan os.Signal, 10) signal.Notify(signalCh, os.Interrupt, syscall.SIGTERM, syscall.SIGHUP, syscall.SIGPIPE) ctx, cancel := context.WithCancel(context.Background()) go func() { for { var sig os.Signal select { case s := <-signalCh: sig = s case <-ctx.Done(): return } switch sig { case syscall.SIGPIPE: continue case syscall.SIGHUP: err := fmt.Errorf("cannot reload before agent started") c.logger.Error("Caught", "signal", sig, "error", err) default: c.logger.Info("Caught", "signal", sig) cancel() return } } }() err = agent.Start(ctx) signal.Stop(signalCh) cancel() if err != nil { c.logger.Error("Error starting agent", "error", err) return 1 } // shutdown agent before endpoints defer agent.ShutdownEndpoints() defer agent.ShutdownAgent() if !config.DisableUpdateCheck && !config.DevMode { c.startupUpdateCheck(config) } if err := c.startupJoin(agent, config); err != nil { c.logger.Error(err.Error()) return 1 } if err := c.startupJoinWan(agent, config); err != nil { c.logger.Error(err.Error()) return 1 } // Let the agent know we've finished registration agent.StartSync() c.logger.Info("Consul agent running!") // wait for signal signalCh = make(chan os.Signal, 10) signal.Notify(signalCh, os.Interrupt, syscall.SIGTERM, syscall.SIGHUP, syscall.SIGPIPE) for { var sig os.Signal select { case s := <-signalCh: sig = s case <-service_os.Shutdown_Channel(): sig = os.Interrupt case err := <-agent.RetryJoinCh(): c.logger.Error("Retry join failed", "error", err) return 1 case <-agent.Failed(): // The deferred Shutdown method will log the appropriate error return 1 case <-agent.ShutdownCh(): // agent is already down! return 0 } switch sig { case syscall.SIGPIPE: continue case syscall.SIGHUP: c.logger.Info("Caught", "signal", sig) err := agent.ReloadConfig() if err != nil { c.logger.Error("Reload config failed", "error", err) } config = agent.GetConfig() default: c.logger.Info("Caught", "signal", sig) graceful := (sig == os.Interrupt && !(config.SkipLeaveOnInt)) || (sig == syscall.SIGTERM && (config.LeaveOnTerm)) if !graceful { c.logger.Info("Graceful shutdown disabled. Exiting") return 1 } c.logger.Info("Gracefully shutting down agent...") gracefulCh := make(chan struct{}) go func() { if err := agent.Leave(); err != nil { c.logger.Error("Error on leave", "error", err) return } close(gracefulCh) }() gracefulTimeout := 15 * time.Second select { case <-signalCh: c.logger.Info("Caught second signal, Exiting", "signal", sig) return 1 case <-time.After(gracefulTimeout): c.logger.Info("Timeout on graceful leave. Exiting") return 1 case <-gracefulCh: c.logger.Info("Graceful exit completed") return 0 } } } } func (c *cmd) Synopsis() string { return synopsis } func (c *cmd) Help() string { return c.help } const synopsis = "Runs a Consul agent" const help = ` Usage: consul agent [options] Starts the Consul agent and runs until an interrupt is received. The agent represents a single node in a cluster. `