open-consul/command/agent/agent.go
Daniel Nephin b93d63b8d2 cmd: remove unnecessary GatedUi
The intent of this struct was to prevent non-json output to stdout. With
the previous cleanup, this can now be done by simply changing the stdout
stream to io.Discard.

This is just one example of why passing around io.Writers for the
streams is better than the UI interface.
2021-06-02 17:33:20 -04:00

359 lines
9.5 KiB
Go

package agent
import (
"context"
"flag"
"fmt"
"io"
"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),
}
config.AddFlags(c.flags, &c.configLoadOpts)
c.help = flags.Usage(help, c.flags)
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
configLoadOpts config.LoadOpts
logger hclog.InterceptLogger
}
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Outdated {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) (config.LoadResult, error) {
c.configLoadOpts.DefaultConfig = source
return config.Load(c.configLoadOpts)
}
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: io.Discard},
}
}
ui.Output("Starting Consul agent...")
segment := config.SegmentName
if config.ServerMode {
segment = "<all>"
}
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.
`