forked from hashicorp/consul
/
command.go
540 lines (463 loc) · 15.7 KB
/
command.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
package agent
import (
"flag"
"fmt"
"github.com/armon/go-metrics"
"github.com/hashicorp/go-syslog"
"github.com/hashicorp/logutils"
"github.com/mitchellh/cli"
"io"
"net"
"os"
"os/signal"
"regexp"
"runtime"
"strings"
"syscall"
"time"
)
// gracefulTimeout controls how long we wait before forcefully terminating
var gracefulTimeout = 5 * time.Second
// validDatacenter is used to validate a datacenter
var validDatacenter = regexp.MustCompile("^[a-zA-Z0-9_-]+$")
// Command 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 Command struct {
Revision string
Version string
VersionPrerelease string
Ui cli.Ui
ShutdownCh <-chan struct{}
args []string
logFilter *logutils.LevelFilter
agent *Agent
rpcServer *AgentRPC
httpServer *HTTPServer
dnsServer *DNSServer
}
// readConfig is responsible for setup of our configuration using
// the command line and any file configs
func (c *Command) readConfig() *Config {
var cmdConfig Config
var configFiles []string
cmdFlags := flag.NewFlagSet("agent", flag.ContinueOnError)
cmdFlags.Usage = func() { c.Ui.Output(c.Help()) }
cmdFlags.Var((*AppendSliceValue)(&configFiles), "config-file", "json file to read config from")
cmdFlags.Var((*AppendSliceValue)(&configFiles), "config-dir", "directory of json files to read")
cmdFlags.StringVar(&cmdConfig.LogLevel, "log-level", "", "log level")
cmdFlags.StringVar(&cmdConfig.NodeName, "node", "", "node name")
cmdFlags.StringVar(&cmdConfig.Datacenter, "dc", "", "node datacenter")
cmdFlags.StringVar(&cmdConfig.DataDir, "data-dir", "", "path to the data directory")
cmdFlags.StringVar(&cmdConfig.UiDir, "ui-dir", "", "path to the web UI directory")
cmdFlags.StringVar(&cmdConfig.PidFile, "pid-file", "", "path to file to store PID")
cmdFlags.BoolVar(&cmdConfig.Server, "server", false, "run agent as server")
cmdFlags.BoolVar(&cmdConfig.Bootstrap, "bootstrap", false, "enable server bootstrap mode")
cmdFlags.StringVar(&cmdConfig.ClientAddr, "client", "", "address to bind client listeners to (DNS, HTTP, RPC)")
cmdFlags.StringVar(&cmdConfig.BindAddr, "bind", "", "address to bind server listeners to")
cmdFlags.StringVar(&cmdConfig.AdvertiseAddr, "advertise", "", "address to advertise instead of bind addr")
cmdFlags.IntVar(&cmdConfig.Protocol, "protocol", -1, "protocol version")
cmdFlags.BoolVar(&cmdConfig.EnableSyslog, "syslog", false,
"enable logging to syslog facility")
cmdFlags.BoolVar(&cmdConfig.RejoinAfterLeave, "rejoin", false,
"enable re-joining after a previous leave")
cmdFlags.Var((*AppendSliceValue)(&cmdConfig.StartJoin), "join",
"address of agent to join on startup")
if err := cmdFlags.Parse(c.args); err != nil {
return nil
}
config := DefaultConfig()
if len(configFiles) > 0 {
fileConfig, err := ReadConfigPaths(configFiles)
if err != nil {
c.Ui.Error(err.Error())
return nil
}
config = MergeConfig(config, fileConfig)
}
config = MergeConfig(config, &cmdConfig)
if config.NodeName == "" {
hostname, err := os.Hostname()
if err != nil {
c.Ui.Error(fmt.Sprintf("Error determining hostname: %s", err))
return nil
}
config.NodeName = hostname
}
if config.EncryptKey != "" {
if _, err := config.EncryptBytes(); err != nil {
c.Ui.Error(fmt.Sprintf("Invalid encryption key: %s", err))
return nil
}
}
// Ensure we have a data directory
if config.DataDir == "" {
c.Ui.Error("Must specify data directory using -data-dir")
return nil
}
// Verify data center is valid
if !validDatacenter.MatchString(config.Datacenter) {
c.Ui.Error("Datacenter must be alpha-numeric with underscores and hypens only")
return nil
}
// Only allow bootstrap mode when acting as a server
if config.Bootstrap && !config.Server {
c.Ui.Error("Bootstrap mode cannot be enabled when server mode is not enabled")
return nil
}
// Warn if we are in bootstrap mode
if config.Bootstrap {
c.Ui.Error("WARNING: Bootstrap mode enabled! Do not enable unless necessary")
}
// Warn if using windows as a server
if config.Server && runtime.GOOS == "windows" {
c.Ui.Error("WARNING: Windows is not recommended as a Consul server. Do not use in production.")
}
// Set the version info
config.Revision = c.Revision
config.Version = c.Version
config.VersionPrerelease = c.VersionPrerelease
return config
}
// setupLoggers is used to setup the logGate, logWriter, and our logOutput
func (c *Command) setupLoggers(config *Config) (*GatedWriter, *logWriter, io.Writer) {
// Setup logging. First create the gated log writer, which will
// store logs until we're ready to show them. Then create the level
// filter, filtering logs of the specified level.
logGate := &GatedWriter{
Writer: &cli.UiWriter{Ui: c.Ui},
}
c.logFilter = LevelFilter()
c.logFilter.MinLevel = logutils.LogLevel(strings.ToUpper(config.LogLevel))
c.logFilter.Writer = logGate
if !ValidateLevelFilter(c.logFilter.MinLevel, c.logFilter) {
c.Ui.Error(fmt.Sprintf(
"Invalid log level: %s. Valid log levels are: %v",
c.logFilter.MinLevel, c.logFilter.Levels))
return nil, nil, nil
}
// Check if syslog is enabled
var syslog io.Writer
if config.EnableSyslog {
l, err := gsyslog.NewLogger(gsyslog.LOG_NOTICE, config.SyslogFacility, "consul")
if err != nil {
c.Ui.Error(fmt.Sprintf("Syslog setup failed: %v", err))
return nil, nil, nil
}
syslog = &SyslogWrapper{l}
}
// Create a log writer, and wrap a logOutput around it
logWriter := NewLogWriter(512)
var logOutput io.Writer
if syslog != nil {
logOutput = io.MultiWriter(c.logFilter, logWriter, syslog)
} else {
logOutput = io.MultiWriter(c.logFilter, logWriter)
}
return logGate, logWriter, logOutput
}
// setupAgent is used to start the agent and various interfaces
func (c *Command) setupAgent(config *Config, logOutput io.Writer, logWriter *logWriter) error {
c.Ui.Output("Starting Consul agent...")
agent, err := Create(config, logOutput)
if err != nil {
c.Ui.Error(fmt.Sprintf("Error starting agent: %s", err))
return err
}
c.agent = agent
// Setup the RPC listener
rpcAddr, err := config.ClientListener(config.Ports.RPC)
if err != nil {
c.Ui.Error(fmt.Sprintf("Invalid RPC bind address: %s", err))
return err
}
rpcListener, err := net.Listen("tcp", rpcAddr.String())
if err != nil {
agent.Shutdown()
c.Ui.Error(fmt.Sprintf("Error starting RPC listener: %s", err))
return err
}
// Start the IPC layer
c.Ui.Output("Starting Consul agent RPC...")
c.rpcServer = NewAgentRPC(agent, rpcListener, logOutput, logWriter)
if config.Ports.HTTP > 0 {
httpAddr, err := config.ClientListener(config.Ports.HTTP)
if err != nil {
c.Ui.Error(fmt.Sprintf("Invalid HTTP bind address: %s", err))
return err
}
server, err := NewHTTPServer(agent, config.UiDir, config.EnableDebug, logOutput, httpAddr.String())
if err != nil {
agent.Shutdown()
c.Ui.Error(fmt.Sprintf("Error starting http server: %s", err))
return err
}
c.httpServer = server
}
if config.Ports.DNS > 0 {
dnsAddr, err := config.ClientListener(config.Ports.DNS)
if err != nil {
c.Ui.Error(fmt.Sprintf("Invalid DNS bind address: %s", err))
return err
}
server, err := NewDNSServer(agent, &config.DNSConfig, logOutput,
config.Domain, dnsAddr.String(), config.DNSRecursor)
if err != nil {
agent.Shutdown()
c.Ui.Error(fmt.Sprintf("Error starting dns server: %s", err))
return err
}
c.dnsServer = server
}
return nil
}
// startupJoin is invoked to handle any joins specified to take place at start time
func (c *Command) startupJoin(config *Config) error {
if len(config.StartJoin) == 0 {
return nil
}
c.Ui.Output("Joining cluster...")
n, err := c.agent.JoinLAN(config.StartJoin)
if err != nil {
return err
}
c.Ui.Info(fmt.Sprintf("Join completed. Synced with %d initial agents", n))
return nil
}
func (c *Command) Run(args []string) int {
c.Ui = &cli.PrefixedUi{
OutputPrefix: "==> ",
InfoPrefix: " ",
ErrorPrefix: "==> ",
Ui: c.Ui,
}
// Parse our configs
c.args = args
config := c.readConfig()
if config == nil {
return 1
}
c.args = args
// Check GOMAXPROCS
if runtime.GOMAXPROCS(0) == 1 {
c.Ui.Error("WARNING: It is highly recommended to set GOMAXPROCS higher than 1")
}
// Setup the log outputs
logGate, logWriter, logOutput := c.setupLoggers(config)
if logWriter == nil {
return 1
}
/* Setup telemetry
Aggregate on 10 second intervals for 1 minute. Expose the
metrics over stderr when there is a SIGUSR1 received.
*/
inm := metrics.NewInmemSink(10*time.Second, time.Minute)
metrics.DefaultInmemSignal(inm)
metricsConf := metrics.DefaultConfig("consul")
// Optionally configure a statsite sink if provided
if config.StatsiteAddr != "" {
sink, err := metrics.NewStatsiteSink(config.StatsiteAddr)
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to start statsite sink. Got: %s", err))
return 1
}
fanout := metrics.FanoutSink{inm, sink}
metrics.NewGlobal(metricsConf, fanout)
} else {
metricsConf.EnableHostname = false
metrics.NewGlobal(metricsConf, inm)
}
// Create the agent
if err := c.setupAgent(config, logOutput, logWriter); err != nil {
return 1
}
defer c.agent.Shutdown()
if c.rpcServer != nil {
defer c.rpcServer.Shutdown()
}
if c.httpServer != nil {
defer c.httpServer.Shutdown()
}
// Join startup nodes if specified
if err := c.startupJoin(config); err != nil {
c.Ui.Error(err.Error())
return 1
}
// Register the services
for _, service := range config.Services {
ns := service.NodeService()
chkType := service.CheckType()
if err := c.agent.AddService(ns, chkType); err != nil {
c.Ui.Error(fmt.Sprintf("Failed to register service '%s': %v", service.Name, err))
return 1
}
}
// Register the checks
for _, check := range config.Checks {
health := check.HealthCheck(config.NodeName)
chkType := &check.CheckType
if err := c.agent.AddCheck(health, chkType); err != nil {
c.Ui.Error(fmt.Sprintf("Failed to register check '%s': %v %v", check.Name, err, check))
return 1
}
}
// Let the agent know we've finished registration
c.agent.StartSync()
c.Ui.Output("Consul agent running!")
c.Ui.Info(fmt.Sprintf(" Node name: '%s'", config.NodeName))
c.Ui.Info(fmt.Sprintf(" Datacenter: '%s'", config.Datacenter))
c.Ui.Info(fmt.Sprintf(" Server: %v (bootstrap: %v)", config.Server, config.Bootstrap))
c.Ui.Info(fmt.Sprintf(" Client Addr: %v (HTTP: %d, DNS: %d, RPC: %d)", config.ClientAddr,
config.Ports.HTTP, config.Ports.DNS, config.Ports.RPC))
c.Ui.Info(fmt.Sprintf(" Cluster Addr: %v (LAN: %d, WAN: %d)", config.AdvertiseAddr,
config.Ports.SerfLan, config.Ports.SerfWan))
c.Ui.Info(fmt.Sprintf("Gossip encrypt: %v, RPC-TLS: %v, TLS-Incoming: %v",
config.EncryptKey != "", 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 exit
return c.handleSignals(config)
}
// handleSignals blocks until we get an exit-causing signal
func (c *Command) handleSignals(config *Config) int {
signalCh := make(chan os.Signal, 4)
signal.Notify(signalCh, os.Interrupt, syscall.SIGTERM, syscall.SIGHUP)
// Wait for a signal
WAIT:
var sig os.Signal
select {
case s := <-signalCh:
sig = s
case <-c.rpcServer.ReloadCh():
sig = syscall.SIGHUP
case <-c.ShutdownCh:
sig = os.Interrupt
case <-c.agent.ShutdownCh():
// Agent is already shutdown!
return 0
}
c.Ui.Output(fmt.Sprintf("Caught signal: %v", sig))
// Check if this is a SIGHUP
if sig == syscall.SIGHUP {
config = c.handleReload(config)
goto WAIT
}
// Check if we should do a graceful leave
graceful := false
if sig == os.Interrupt && !config.SkipLeaveOnInt {
graceful = true
} else if sig == syscall.SIGTERM && config.LeaveOnTerm {
graceful = true
}
// Bail fast if not doing a graceful leave
if !graceful {
return 1
}
// Attempt a graceful leave
gracefulCh := make(chan struct{})
c.Ui.Output("Gracefully shutting down agent...")
go func() {
if err := c.agent.Leave(); err != nil {
c.Ui.Error(fmt.Sprintf("Error: %s", err))
return
}
close(gracefulCh)
}()
// Wait for leave or another signal
select {
case <-signalCh:
return 1
case <-time.After(gracefulTimeout):
return 1
case <-gracefulCh:
return 0
}
}
// handleReload is invoked when we should reload our configs, e.g. SIGHUP
func (c *Command) handleReload(config *Config) *Config {
c.Ui.Output("Reloading configuration...")
newConf := c.readConfig()
if newConf == nil {
c.Ui.Error(fmt.Sprintf("Failed to reload configs"))
return config
}
// Change the log level
minLevel := logutils.LogLevel(strings.ToUpper(newConf.LogLevel))
if ValidateLevelFilter(minLevel, c.logFilter) {
c.logFilter.SetMinLevel(minLevel)
} else {
c.Ui.Error(fmt.Sprintf(
"Invalid log level: %s. Valid log levels are: %v",
minLevel, c.logFilter.Levels))
// Keep the current log level
newConf.LogLevel = config.LogLevel
}
// Bulk update the services and checks
c.agent.PauseSync()
defer c.agent.ResumeSync()
// Deregister the old services
for _, service := range config.Services {
ns := service.NodeService()
c.agent.RemoveService(ns.ID)
}
// Deregister the old checks
for _, check := range config.Checks {
health := check.HealthCheck(config.NodeName)
c.agent.RemoveCheck(health.CheckID)
}
// Register the services
for _, service := range newConf.Services {
ns := service.NodeService()
chkType := service.CheckType()
if err := c.agent.AddService(ns, chkType); err != nil {
c.Ui.Error(fmt.Sprintf("Failed to register service '%s': %v", service.Name, err))
}
}
// Register the checks
for _, check := range newConf.Checks {
health := check.HealthCheck(config.NodeName)
chkType := &check.CheckType
if err := c.agent.AddCheck(health, chkType); err != nil {
c.Ui.Error(fmt.Sprintf("Failed to register check '%s': %v %v", check.Name, err, check))
}
}
return newConf
}
func (c *Command) Synopsis() string {
return "Runs a Consul agent"
}
func (c *Command) Help() string {
helpText := `
Usage: consul agent [options]
Starts the Consul agent and runs until an interrupt is received. The
agent represents a single node in a cluster.
Options:
-advertise=addr Sets the advertise address to use
-bootstrap Sets server to bootstrap mode
-bind=0.0.0.0 Sets the bind address for cluster communication
-client=127.0.0.1 Sets the address to bind for client access.
This includes RPC, DNS and HTTP
-config-file=foo Path to a JSON file to read configuration from.
This can be specified multiple times.
-config-dir=foo Path to a directory to read configuration files
from. This will read every file ending in ".json"
as configuration in this directory in alphabetical
order.
-data-dir=path Path to a data directory to store agent state
-dc=east-aws Datacenter of the agent
-join=1.2.3.4 Address of an agent to join at start time.
Can be specified multiple times.
-log-level=info Log level of the agent.
-node=hostname Name of this node. Must be unique in the cluster
-protocol=N Sets the protocol version. Defaults to latest.
-rejoin Ignores a previous leave and attempts to rejoin the cluster.
-server Switches agent to server mode.
-syslog Enables logging to syslog
-ui-dir=path Path to directory containing the Web UI resources
-pid-file=path Path to file to store agent PID
`
return strings.TrimSpace(helpText)
}