open-consul/command/agent/agent.go

390 lines
10 KiB
Go

package agent
import (
"flag"
"fmt"
"io"
"log"
"os"
"os/signal"
"path/filepath"
"strings"
"syscall"
"time"
"github.com/hashicorp/consul/agent"
"github.com/hashicorp/consul/agent/config"
"github.com/hashicorp/consul/command/flags"
"github.com/hashicorp/consul/lib"
"github.com/hashicorp/consul/logger"
"github.com/hashicorp/go-checkpoint"
multierror "github.com/hashicorp/go-multierror"
"github.com/hashicorp/logutils"
"github.com/mitchellh/cli"
)
func New(ui cli.Ui, revision, version, versionPre, versionHuman string, shutdownCh <-chan struct{}) *cmd {
ui = &cli.PrefixedUi{
OutputPrefix: "==> ",
InfoPrefix: " ",
ErrorPrefix: "==> ",
Ui: ui,
}
c := &cmd{
UI: ui,
revision: revision,
version: version,
versionPrerelease: versionPre,
versionHuman: versionHuman,
shutdownCh: shutdownCh,
}
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
shutdownCh <-chan struct{}
flagArgs config.Flags
logFilter *logutils.LevelFilter
logOutput io.Writer
logger *log.Logger
}
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.Println("[INFO] agent: Exit code:", code)
}
return code
}
// readConfig is responsible for setup of our configuration using
// the command line and any file configs
func (c *cmd) readConfig() *config.RuntimeConfig {
b, err := config.NewBuilder(c.flagArgs)
if err != nil {
c.UI.Error(err.Error())
return nil
}
cfg, err := b.BuildAndValidate()
if err != nil {
c.UI.Error(err.Error())
return nil
}
for _, w := range b.Warnings {
c.UI.Warn(w)
}
return &cfg
}
// checkpointResults is used to handler periodic results from our update checker
func (c *cmd) checkpointResults(results *checkpoint.CheckResponse, err error) {
if err != nil {
c.UI.Error(fmt.Sprintf("Failed to check for updates: %v", err))
return
}
if results.Outdated {
c.UI.Error(fmt.Sprintf("Newer Consul version available: %s (currently running: %s)", results.CurrentVersion, c.version))
}
for _, alert := range results.Alerts {
switch alert.Level {
case "info":
c.UI.Info(fmt.Sprintf("Bulletin [%s]: %s (%s)", alert.Level, alert.Message, alert.URL))
default:
c.UI.Error(fmt.Sprintf("Bulletin [%s]: %s (%s)", alert.Level, alert.Message, 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.UI.Output("Joining cluster...")
n, err := agent.JoinLAN(cfg.StartJoinAddrsLAN)
if err != nil {
return err
}
c.UI.Info(fmt.Sprintf("Join completed. Synced with %d initial agents", 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.UI.Output("Joining -wan cluster...")
n, err := agent.JoinWAN(cfg.StartJoinAddrsWAN)
if err != nil {
return err
}
c.UI.Info(fmt.Sprintf("Join -wan completed. Synced with %d initial agents", n))
return nil
}
func (c *cmd) run(args []string) int {
// Parse our configs
if err := c.flags.Parse(args); err != nil {
if !strings.Contains(err.Error(), "help requested") {
c.UI.Error(fmt.Sprintf("error parsing flags: %v", err))
}
return 1
}
c.flagArgs.Args = c.flags.Args()
config := c.readConfig()
if config == nil {
return 1
}
// Setup the log outputs
logConfig := &logger.Config{
LogLevel: config.LogLevel,
EnableSyslog: config.EnableSyslog,
SyslogFacility: config.SyslogFacility,
}
logFilter, logGate, logWriter, logOutput, ok := logger.Setup(logConfig, c.UI)
if !ok {
return 1
}
c.logFilter = logFilter
c.logOutput = logOutput
c.logger = log.New(logOutput, "", log.LstdFlags)
memSink, err := lib.InitTelemetry(config.Telemetry)
if err != nil {
c.UI.Error(err.Error())
return 1
}
// Create the agent
c.UI.Output("Starting Consul agent...")
agent, err := agent.New(config)
if err != nil {
c.UI.Error(fmt.Sprintf("Error creating agent: %s", err))
return 1
}
agent.LogOutput = logOutput
agent.LogWriter = logWriter
agent.MemSink = memSink
if err := agent.Start(); err != nil {
c.UI.Error(fmt.Sprintf("Error starting agent: %s", err))
return 1
}
// shutdown agent before endpoints
defer agent.ShutdownEndpoints()
defer agent.ShutdownAgent()
if !config.DisableUpdateCheck {
c.startupUpdateCheck(config)
}
if err := c.startupJoin(agent, config); err != nil {
c.UI.Error(err.Error())
return 1
}
if err := c.startupJoinWan(agent, config); err != nil {
c.UI.Error(err.Error())
return 1
}
// Let the agent know we've finished registration
agent.StartSync()
segment := config.SegmentName
if config.ServerMode {
segment = "<all>"
}
c.UI.Output("Consul agent running!")
c.UI.Info(fmt.Sprintf(" Version: '%s'", c.versionHuman))
c.UI.Info(fmt.Sprintf(" Node ID: '%s'", config.NodeID))
c.UI.Info(fmt.Sprintf(" Node name: '%s'", config.NodeName))
c.UI.Info(fmt.Sprintf(" Datacenter: '%s' (Segment: '%s')", config.Datacenter, segment))
c.UI.Info(fmt.Sprintf(" Server: %v (Bootstrap: %v)", config.ServerMode, config.Bootstrap))
c.UI.Info(fmt.Sprintf(" Client Addr: %v (HTTP: %d, HTTPS: %d, DNS: %d)", config.ClientAddrs,
config.HTTPPort, config.HTTPSPort, config.DNSPort))
c.UI.Info(fmt.Sprintf(" Cluster Addr: %v (LAN: %d, WAN: %d)", config.AdvertiseAddrLAN,
config.SerfPortLAN, config.SerfPortWAN))
c.UI.Info(fmt.Sprintf(" Encrypt: Gossip: %v, TLS-Outgoing: %v, TLS-Incoming: %v",
agent.GossipEncrypted(), config.VerifyOutgoing, config.VerifyIncoming))
// Enable log streaming
c.UI.Info("")
c.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)
for {
var sig os.Signal
var reloadErrCh chan error
select {
case s := <-signalCh:
sig = s
case ch := <-agent.ReloadCh():
sig = syscall.SIGHUP
reloadErrCh = ch
case <-c.shutdownCh:
sig = os.Interrupt
case err := <-agent.RetryJoinCh():
c.logger.Println("[ERR] agent: Retry join failed: ", err)
return 1
case <-agent.ShutdownCh():
// agent is already down!
return 0
}
switch sig {
case syscall.SIGPIPE:
continue
case syscall.SIGHUP:
c.logger.Println("[INFO] agent: Caught signal: ", sig)
conf, err := c.handleReload(agent, config)
if conf != nil {
config = conf
}
if err != nil {
c.logger.Println("[ERR] agent: Reload config failed: ", err)
}
// Send result back if reload was called via HTTP
if reloadErrCh != nil {
reloadErrCh <- err
}
default:
c.logger.Println("[INFO] agent: Caught signal: ", sig)
graceful := (sig == os.Interrupt && !(config.SkipLeaveOnInt)) || (sig == syscall.SIGTERM && (config.LeaveOnTerm))
if !graceful {
c.logger.Println("[INFO] agent: Graceful shutdown disabled. Exiting")
return 1
}
c.logger.Println("[INFO] agent: Gracefully shutting down agent...")
gracefulCh := make(chan struct{})
go func() {
if err := agent.Leave(); err != nil {
c.logger.Println("[ERR] agent: Error on leave:", err)
return
}
close(gracefulCh)
}()
gracefulTimeout := 15 * time.Second
select {
case <-signalCh:
c.logger.Printf("[INFO] agent: Caught second signal %v. Exiting\n", sig)
return 1
case <-time.After(gracefulTimeout):
c.logger.Println("[INFO] agent: Timeout on graceful leave. Exiting")
return 1
case <-gracefulCh:
c.logger.Println("[INFO] agent: Graceful exit completed")
return 0
}
}
}
}
// handleReload is invoked when we should reload our configs, e.g. SIGHUP
func (c *cmd) handleReload(agent *agent.Agent, cfg *config.RuntimeConfig) (*config.RuntimeConfig, error) {
c.logger.Println("[INFO] agent: Reloading configuration...")
var errs error
newCfg := c.readConfig()
if newCfg == nil {
errs = multierror.Append(errs, fmt.Errorf("Failed to reload configs"))
return cfg, errs
}
// Change the log level
minLevel := logutils.LogLevel(strings.ToUpper(newCfg.LogLevel))
if logger.ValidateLevelFilter(minLevel, c.logFilter) {
c.logFilter.SetMinLevel(minLevel)
} else {
errs = multierror.Append(fmt.Errorf(
"Invalid log level: %s. Valid log levels are: %v",
minLevel, c.logFilter.Levels))
// Keep the current log level
newCfg.LogLevel = cfg.LogLevel
}
if err := agent.ReloadConfig(newCfg); err != nil {
errs = multierror.Append(fmt.Errorf(
"Failed to reload configs: %v", err))
}
return newCfg, errs
}
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.
`