Merge pull request #312 from hashicorp/f-rexec

Adding support for 'exec' command
This commit is contained in:
Armon Dadgar 2014-09-01 15:08:31 -07:00
commit c534bc9602
16 changed files with 1641 additions and 18 deletions

View File

@ -235,6 +235,10 @@ type Config struct {
// agent layer using the standard APIs.
Watches []map[string]interface{} `mapstructure:"watches"`
// DisableRemoteExec is used to turn off the remote execution
// feature. This is for security to prevent unknown scripts from running.
DisableRemoteExec bool `mapstructure:"disable_remote_exec"`
// AEInterval controls the anti-entropy interval. This is how often
// the agent attempts to reconcile it's local state with the server'
// representation of our state. Defaults to every 60s.
@ -676,6 +680,9 @@ func MergeConfig(a, b *Config) *Config {
if len(b.WatchPlans) != 0 {
result.WatchPlans = append(result.WatchPlans, b.WatchPlans...)
}
if b.DisableRemoteExec {
result.DisableRemoteExec = true
}
// Copy the start join addresses
result.StartJoin = make([]string, 0, len(a.StartJoin)+len(b.StartJoin))

View File

@ -405,6 +405,17 @@ func TestDecodeConfig(t *testing.T) {
if !reflect.DeepEqual(out, exp) {
t.Fatalf("bad: %#v", config)
}
// remote exec
input = `{"disable_remote_exec": true}`
config, err = DecodeConfig(bytes.NewReader([]byte(input)))
if err != nil {
t.Fatalf("err: %s", err)
}
if !config.DisableRemoteExec {
t.Fatalf("bad: %#v", config)
}
}
func TestDecodeConfig_Service(t *testing.T) {
@ -566,6 +577,7 @@ func TestMergeConfig(t *testing.T) {
"handler": "foobar",
},
},
DisableRemoteExec: true,
}
c := MergeConfig(a, b)

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@ -0,0 +1,319 @@
package agent
import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
"os/exec"
"path"
"strconv"
"sync"
"syscall"
"time"
"github.com/hashicorp/consul/consul/structs"
)
const (
// remoteExecFileName is the name of the file we append to
// the path, e.g. _rexec/session_id/job
remoteExecFileName = "job"
// rExecAck is the suffix added to an ack path
remoteExecAckSuffix = "ack"
// remoteExecAck is the suffix added to an exit code
remoteExecExitSuffix = "exit"
// remoteExecOutputDivider is used to namespace the output
remoteExecOutputDivider = "out"
// remoteExecOutputSize is the size we chunk output too
remoteExecOutputSize = 4 * 1024
// remoteExecOutputDeadline is how long we wait before uploading
// less than the chunk size
remoteExecOutputDeadline = 500 * time.Millisecond
)
// remoteExecEvent is used as the payload of the user event to transmit
// what we need to know about the event
type remoteExecEvent struct {
Prefix string
Session string
}
// remoteExecSpec is used as the specification of the remote exec.
// It is stored in the KV store
type remoteExecSpec struct {
Command string
Script []byte
Wait time.Duration
}
type rexecWriter struct {
BufCh chan []byte
BufSize int
BufIdle time.Duration
CancelCh chan struct{}
buf []byte
bufLen int
bufLock sync.Mutex
flush *time.Timer
}
func (r *rexecWriter) Write(b []byte) (int, error) {
r.bufLock.Lock()
defer r.bufLock.Unlock()
if r.flush != nil {
r.flush.Stop()
r.flush = nil
}
inpLen := len(b)
if r.buf == nil {
r.buf = make([]byte, r.BufSize)
}
COPY:
remain := len(r.buf) - r.bufLen
if remain > len(b) {
copy(r.buf[r.bufLen:], b)
r.bufLen += len(b)
} else {
copy(r.buf[r.bufLen:], b[:remain])
b = b[remain:]
r.bufLen += remain
r.bufLock.Unlock()
r.Flush()
r.bufLock.Lock()
goto COPY
}
r.flush = time.AfterFunc(r.BufIdle, r.Flush)
return inpLen, nil
}
func (r *rexecWriter) Flush() {
r.bufLock.Lock()
defer r.bufLock.Unlock()
if r.flush != nil {
r.flush.Stop()
r.flush = nil
}
if r.bufLen == 0 {
return
}
select {
case r.BufCh <- r.buf[:r.bufLen]:
r.buf = make([]byte, r.BufSize)
r.bufLen = 0
case <-r.CancelCh:
r.bufLen = 0
}
}
// handleRemoteExec is invoked when a new remote exec request is received
func (a *Agent) handleRemoteExec(msg *UserEvent) {
a.logger.Printf("[DEBUG] agent: received remote exec event (ID: %s)", msg.ID)
// Decode the event paylaod
var event remoteExecEvent
if err := json.Unmarshal(msg.Payload, &event); err != nil {
a.logger.Printf("[ERR] agent: failed to decode remote exec event: %v", err)
return
}
// Read the job specification
var spec remoteExecSpec
if !a.remoteExecGetSpec(&event, &spec) {
return
}
// Write the acknowledgement
if !a.remoteExecWriteAck(&event) {
return
}
// Ensure we write out an exit code
exitCode := 0
defer a.remoteExecWriteExitCode(&event, exitCode)
// Check if this is a script, we may need to spill to disk
var script string
if len(spec.Script) != 0 {
tmpFile, err := ioutil.TempFile("", "rexec")
if err != nil {
a.logger.Printf("[DEBUG] agent: failed to make tmp file: %v", err)
exitCode = 255
return
}
defer os.Remove(tmpFile.Name())
os.Chmod(tmpFile.Name(), 0750)
tmpFile.Write(spec.Script)
tmpFile.Close()
script = tmpFile.Name()
} else {
script = spec.Command
}
// Create the exec.Cmd
a.logger.Printf("[INFO] agent: remote exec '%s'", script)
cmd, err := ExecScript(script)
if err != nil {
a.logger.Printf("[DEBUG] agent: failed to start remote exec: %v", err)
exitCode = 255
return
}
// Setup the output streaming
writer := &rexecWriter{
BufCh: make(chan []byte, 16),
BufSize: remoteExecOutputSize,
BufIdle: remoteExecOutputDeadline,
CancelCh: make(chan struct{}),
}
cmd.Stdout = writer
cmd.Stderr = writer
// Start execution
err = cmd.Start()
if err != nil {
a.logger.Printf("[DEBUG] agent: failed to start remote exec: %v", err)
exitCode = 255
return
}
// Wait for the process to exit
exitCh := make(chan int, 1)
go func() {
err := cmd.Wait()
writer.Flush()
close(writer.BufCh)
if err != nil {
exitCh <- 0
return
}
// Try to determine the exit code
if exitErr, ok := err.(*exec.ExitError); ok {
if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
exitCh <- status.ExitStatus()
return
}
}
exitCh <- 1
}()
// Wait until we are complete, uploading as we go
WAIT:
for num := 0; ; num++ {
select {
case out := <-writer.BufCh:
if out == nil {
break WAIT
}
if !a.remoteExecWriteOutput(&event, num, out) {
close(writer.CancelCh)
exitCode = 255
return
}
case <-time.After(spec.Wait):
// Acts like a heartbeat, since there is no output
if !a.remoteExecWriteOutput(&event, num, nil) {
close(writer.CancelCh)
exitCode = 255
return
}
}
}
// Get the exit code
exitCode = <-exitCh
}
// remoteExecGetSpec is used to get the exec specification.
// Returns if execution should continue
func (a *Agent) remoteExecGetSpec(event *remoteExecEvent, spec *remoteExecSpec) bool {
get := structs.KeyRequest{
Datacenter: a.config.Datacenter,
Key: path.Join(event.Prefix, event.Session, remoteExecFileName),
QueryOptions: structs.QueryOptions{
AllowStale: true, // Stale read for scale! Retry on failure.
},
}
var out structs.IndexedDirEntries
QUERY:
if err := a.RPC("KVS.Get", &get, &out); err != nil {
a.logger.Printf("[ERR] agent: failed to get remote exec job: %v", err)
return false
}
if len(out.Entries) == 0 {
// If the initial read was stale and had no data, retry as a consistent read
if get.QueryOptions.AllowStale {
a.logger.Printf("[DEBUG] agent: trying consistent fetch of remote exec job spec")
get.QueryOptions.AllowStale = false
goto QUERY
} else {
a.logger.Printf("[DEBUG] agent: remote exec aborted, job spec missing")
return false
}
}
if err := json.Unmarshal(out.Entries[0].Value, &spec); err != nil {
a.logger.Printf("[ERR] agent: failed to decode remote exec spec: %v", err)
return false
}
return true
}
// remoteExecWriteAck is used to write an ack. Returns if execution should
// continue.
func (a *Agent) remoteExecWriteAck(event *remoteExecEvent) bool {
if err := a.remoteExecWriteKey(event, remoteExecAckSuffix, nil); err != nil {
a.logger.Printf("[ERR] agent: failed to ack remote exec job: %v", err)
return false
}
return true
}
// remoteExecWriteOutput is used to write output
func (a *Agent) remoteExecWriteOutput(event *remoteExecEvent, num int, output []byte) bool {
suffix := path.Join(remoteExecOutputDivider, fmt.Sprintf("%05x", num))
if err := a.remoteExecWriteKey(event, suffix, output); err != nil {
a.logger.Printf("[ERR] agent: failed to write output for remote exec job: %v", err)
return false
}
return true
}
// remoteExecWriteExitCode is used to write an exit code
func (a *Agent) remoteExecWriteExitCode(event *remoteExecEvent, exitCode int) bool {
val := []byte(strconv.FormatInt(int64(exitCode), 10))
if err := a.remoteExecWriteKey(event, remoteExecExitSuffix, val); err != nil {
a.logger.Printf("[ERR] agent: failed to write exit code for remote exec job: %v", err)
return false
}
return true
}
// remoteExecWriteKey is used to write an output key for a remote exec job
func (a *Agent) remoteExecWriteKey(event *remoteExecEvent, suffix string, val []byte) error {
key := path.Join(event.Prefix, event.Session, a.config.NodeName, suffix)
write := structs.KVSRequest{
Datacenter: a.config.Datacenter,
Op: structs.KVSLock,
DirEnt: structs.DirEntry{
Key: key,
Value: val,
Session: event.Session,
},
}
var success bool
if err := a.RPC("KVS.Apply", &write, &success); err != nil {
return err
}
if !success {
return fmt.Errorf("write failed")
}
return nil
}

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@ -0,0 +1,288 @@
package agent
import (
"bytes"
"encoding/json"
"os"
"reflect"
"testing"
"time"
"github.com/hashicorp/consul/consul/structs"
"github.com/hashicorp/consul/testutil"
)
func TestRexecWriter(t *testing.T) {
writer := &rexecWriter{
BufCh: make(chan []byte, 16),
BufSize: 16,
BufIdle: 10 * time.Millisecond,
CancelCh: make(chan struct{}),
}
// Write short, wait for idle
start := time.Now()
n, err := writer.Write([]byte("test"))
if err != nil {
t.Fatalf("err: %v", err)
}
if n != 4 {
t.Fatalf("bad: %v", n)
}
select {
case b := <-writer.BufCh:
if len(b) != 4 {
t.Fatalf("Bad: %v", b)
}
if time.Now().Sub(start) < writer.BufIdle {
t.Fatalf("too early")
}
case <-time.After(2 * writer.BufIdle):
t.Fatalf("timeout")
}
// Write in succession to prevent the timeout
writer.Write([]byte("test"))
time.Sleep(writer.BufIdle / 2)
writer.Write([]byte("test"))
time.Sleep(writer.BufIdle / 2)
start = time.Now()
writer.Write([]byte("test"))
select {
case b := <-writer.BufCh:
if len(b) != 12 {
t.Fatalf("Bad: %v", b)
}
if time.Now().Sub(start) < writer.BufIdle {
t.Fatalf("too early")
}
case <-time.After(2 * writer.BufIdle):
t.Fatalf("timeout")
}
// Write large values, multiple flushes required
writer.Write([]byte("01234567890123456789012345678901"))
select {
case b := <-writer.BufCh:
if string(b) != "0123456789012345" {
t.Fatalf("bad: %s", b)
}
default:
t.Fatalf("should have buf")
}
select {
case b := <-writer.BufCh:
if string(b) != "6789012345678901" {
t.Fatalf("bad: %s", b)
}
default:
t.Fatalf("should have buf")
}
}
func TestRemoteExecGetSpec(t *testing.T) {
dir, agent := makeAgent(t, nextConfig())
defer os.RemoveAll(dir)
defer agent.Shutdown()
testutil.WaitForLeader(t, agent.RPC, "dc1")
event := &remoteExecEvent{
Prefix: "_rexec",
Session: makeRexecSession(t, agent),
}
defer destroySession(t, agent, event.Session)
spec := &remoteExecSpec{
Command: "uptime",
Script: []byte("#!/bin/bash"),
Wait: time.Second,
}
buf, err := json.Marshal(spec)
if err != nil {
t.Fatalf("err: %v", err)
}
key := "_rexec/" + event.Session + "/job"
setKV(t, agent, key, buf)
var out remoteExecSpec
if !agent.remoteExecGetSpec(event, &out) {
t.Fatalf("bad")
}
if !reflect.DeepEqual(spec, &out) {
t.Fatalf("bad spec")
}
}
func TestRemoteExecWrites(t *testing.T) {
dir, agent := makeAgent(t, nextConfig())
defer os.RemoveAll(dir)
defer agent.Shutdown()
testutil.WaitForLeader(t, agent.RPC, "dc1")
event := &remoteExecEvent{
Prefix: "_rexec",
Session: makeRexecSession(t, agent),
}
defer destroySession(t, agent, event.Session)
if !agent.remoteExecWriteAck(event) {
t.Fatalf("bad")
}
output := []byte("testing")
if !agent.remoteExecWriteOutput(event, 0, output) {
t.Fatalf("bad")
}
if !agent.remoteExecWriteOutput(event, 10, output) {
t.Fatalf("bad")
}
if !agent.remoteExecWriteExitCode(event, 1) {
t.Fatalf("bad")
}
key := "_rexec/" + event.Session + "/" + agent.config.NodeName + "/ack"
d := getKV(t, agent, key)
if d == nil || d.Session != event.Session {
t.Fatalf("bad ack: %#v", d)
}
key = "_rexec/" + event.Session + "/" + agent.config.NodeName + "/out/00000"
d = getKV(t, agent, key)
if d == nil || d.Session != event.Session || !bytes.Equal(d.Value, output) {
t.Fatalf("bad output: %#v", d)
}
key = "_rexec/" + event.Session + "/" + agent.config.NodeName + "/out/0000a"
d = getKV(t, agent, key)
if d == nil || d.Session != event.Session || !bytes.Equal(d.Value, output) {
t.Fatalf("bad output: %#v", d)
}
key = "_rexec/" + event.Session + "/" + agent.config.NodeName + "/exit"
d = getKV(t, agent, key)
if d == nil || d.Session != event.Session || string(d.Value) != "1" {
t.Fatalf("bad output: %#v", d)
}
}
func TestHandleRemoteExec(t *testing.T) {
dir, agent := makeAgent(t, nextConfig())
defer os.RemoveAll(dir)
defer agent.Shutdown()
testutil.WaitForLeader(t, agent.RPC, "dc1")
event := &remoteExecEvent{
Prefix: "_rexec",
Session: makeRexecSession(t, agent),
}
defer destroySession(t, agent, event.Session)
spec := &remoteExecSpec{
Command: "uptime",
Wait: time.Second,
}
buf, err := json.Marshal(spec)
if err != nil {
t.Fatalf("err: %v", err)
}
key := "_rexec/" + event.Session + "/job"
setKV(t, agent, key, buf)
buf, err = json.Marshal(event)
if err != nil {
t.Fatalf("err: %v", err)
}
msg := &UserEvent{
ID: generateUUID(),
Payload: buf,
}
// Handle the event...
agent.handleRemoteExec(msg)
// Verify we have an ack
key = "_rexec/" + event.Session + "/" + agent.config.NodeName + "/ack"
d := getKV(t, agent, key)
if d == nil || d.Session != event.Session {
t.Fatalf("bad ack: %#v", d)
}
// Verify we have output
key = "_rexec/" + event.Session + "/" + agent.config.NodeName + "/out/00000"
d = getKV(t, agent, key)
if d == nil || d.Session != event.Session ||
!bytes.Contains(d.Value, []byte("load")) {
t.Fatalf("bad output: %#v", d)
}
// Verify we have an exit code
key = "_rexec/" + event.Session + "/" + agent.config.NodeName + "/exit"
d = getKV(t, agent, key)
if d == nil || d.Session != event.Session || string(d.Value) != "0" {
t.Fatalf("bad output: %#v", d)
}
}
func makeRexecSession(t *testing.T, agent *Agent) string {
args := structs.SessionRequest{
Datacenter: agent.config.Datacenter,
Op: structs.SessionCreate,
Session: structs.Session{
Node: agent.config.NodeName,
LockDelay: 15 * time.Second,
},
}
var out string
if err := agent.RPC("Session.Apply", &args, &out); err != nil {
t.Fatalf("err: %v", err)
}
return out
}
func destroySession(t *testing.T, agent *Agent, session string) {
args := structs.SessionRequest{
Datacenter: agent.config.Datacenter,
Op: structs.SessionDestroy,
Session: structs.Session{
ID: session,
},
}
var out string
if err := agent.RPC("Session.Apply", &args, &out); err != nil {
t.Fatalf("err: %v", err)
}
}
func setKV(t *testing.T, agent *Agent, key string, val []byte) {
write := structs.KVSRequest{
Datacenter: agent.config.Datacenter,
Op: structs.KVSSet,
DirEnt: structs.DirEntry{
Key: key,
Value: val,
},
}
var success bool
if err := agent.RPC("KVS.Apply", &write, &success); err != nil {
t.Fatalf("err: %v", err)
}
}
func getKV(t *testing.T, agent *Agent, key string) *structs.DirEntry {
req := structs.KeyRequest{
Datacenter: agent.config.Datacenter,
Key: key,
}
var out structs.IndexedDirEntries
if err := agent.RPC("KVS.Get", &req, &out); err != nil {
t.Fatalf("err: %v", err)
}
if len(out.Entries) > 0 {
return out.Entries[0]
}
return nil
}

View File

@ -1,17 +1,18 @@
package agent
import (
"bytes"
"fmt"
"regexp"
"github.com/hashicorp/consul/consul/structs"
"github.com/ugorji/go/codec"
)
const (
// userEventMaxVersion is the maximum protocol version we understand
userEventMaxVersion = 1
// remoteExecName is the event name for a remote exec command
remoteExecName = "_rexec"
)
// UserEventParam is used to parameterize a user event
@ -79,7 +80,7 @@ func (a *Agent) UserEvent(dc string, params *UserEvent) error {
// Format message
params.ID = generateUUID()
params.Version = userEventMaxVersion
payload, err := encodeUserEvent(&params)
payload, err := encodeMsgPack(&params)
if err != nil {
return fmt.Errorf("UserEvent encoding failed: %v", err)
}
@ -114,7 +115,7 @@ func (a *Agent) handleEvents() {
case e := <-a.eventCh:
// Decode the event
msg := new(UserEvent)
if err := decodeUserEvent(e.Payload, msg); err != nil {
if err := decodeMsgPack(e.Payload, msg); err != nil {
a.logger.Printf("[ERR] agent: Failed to decode event: %v", err)
continue
}
@ -208,7 +209,19 @@ func (a *Agent) shouldProcessUserEvent(msg *UserEvent) bool {
// ingestUserEvent is used to process an event that passes filtering
func (a *Agent) ingestUserEvent(msg *UserEvent) {
a.logger.Printf("[DEBUG] agent: new event: %s (%s)", msg.Name, msg.ID)
// Special handling for internal events
switch msg.Name {
case remoteExecName:
if a.config.DisableRemoteExec {
a.logger.Printf("[INFO] agent: ignoring remote exec event (%s), disabled.", msg.ID)
} else {
go a.handleRemoteExec(msg)
}
return
default:
a.logger.Printf("[DEBUG] agent: new event: %s (%s)", msg.Name, msg.ID)
}
a.eventLock.Lock()
defer func() {
a.eventLock.Unlock()
@ -253,15 +266,3 @@ func (a *Agent) LastUserEvent() *UserEvent {
idx := (((a.eventIndex - 1) % n) + n) % n
return a.eventBuf[idx]
}
// Decode is used to decode a MsgPack encoded object
func decodeUserEvent(buf []byte, out interface{}) error {
return codec.NewDecoder(bytes.NewReader(buf), msgpackHandle).Decode(out)
}
// encodeUserEvent is used to encode user event
func encodeUserEvent(msg interface{}) ([]byte, error) {
var buf bytes.Buffer
err := codec.NewEncoder(&buf, msgpackHandle).Encode(msg)
return buf.Bytes(), err
}

View File

@ -1,6 +1,7 @@
package agent
import (
"bytes"
crand "crypto/rand"
"fmt"
"math"
@ -9,6 +10,8 @@ import (
"os/exec"
"runtime"
"time"
"github.com/ugorji/go/codec"
)
const (
@ -76,3 +79,15 @@ func generateUUID() string {
buf[8:10],
buf[10:16])
}
// decodeMsgPack is used to decode a MsgPack encoded object
func decodeMsgPack(buf []byte, out interface{}) error {
return codec.NewDecoder(bytes.NewReader(buf), msgpackHandle).Decode(out)
}
// encodeMsgPack is used to encode an object with msgpack
func encodeMsgPack(msg interface{}) ([]byte, error) {
var buf bytes.Buffer
err := codec.NewEncoder(&buf, msgpackHandle).Encode(msg)
return buf.Bytes(), err
}

574
command/exec.go Normal file
View File

@ -0,0 +1,574 @@
package command
import (
"bytes"
"encoding/json"
"flag"
"fmt"
"io"
"os"
"path"
"regexp"
"strconv"
"strings"
"time"
"unicode"
"github.com/armon/consul-api"
"github.com/mitchellh/cli"
)
const (
// rExecPrefix is the prefix in the KV store used to
// store the remote exec data
rExecPrefix = "_rexec"
// rExecFileName is the name of the file we append to
// the path, e.g. _rexec/session_id/job
rExecFileName = "job"
// rExecAck is the suffix added to an ack path
rExecAckSuffix = "/ack"
// rExecAck is the suffix added to an exit code
rExecExitSuffix = "/exit"
// rExecOutputDivider is used to namespace the output
rExecOutputDivider = "/out/"
// rExecReplicationWait is how long we wait for replication
rExecReplicationWait = 200 * time.Millisecond
// rExecQuietWait is how long we wait for no responses
// before assuming the job is done.
rExecQuietWait = 2 * time.Second
)
// rExecConf is used to pass around configuration
type rExecConf struct {
datacenter string
prefix string
node string
service string
tag string
wait time.Duration
replWait time.Duration
cmd string
script []byte
verbose bool
}
// rExecEvent is the event we broadcast using a user-event
type rExecEvent struct {
Prefix string
Session string
}
// rExecSpec is the file we upload to specify the parameters
// of the remote execution.
type rExecSpec struct {
// Command is a single command to run directly in the shell
Command string `json:",omitempty"`
// Script should be spilled to a file and executed
Script []byte `json:",omitempty"`
// Wait is how long we are waiting on a quiet period to terminate
Wait time.Duration
}
// rExecAck is used to transmit an acknowledgement
type rExecAck struct {
Node string
}
// rExecHeart is used to transmit a heartbeat
type rExecHeart struct {
Node string
}
// rExecOutput is used to transmit a chunk of output
type rExecOutput struct {
Node string
Output []byte
}
// rExecExit is used to transmit an exit code
type rExecExit struct {
Node string
Code int
}
// ExecCommand is a Command implementation that is used to
// do remote execution of commands
type ExecCommand struct {
ShutdownCh <-chan struct{}
Ui cli.Ui
conf rExecConf
client *consulapi.Client
sessionID string
}
func (c *ExecCommand) Run(args []string) int {
cmdFlags := flag.NewFlagSet("exec", flag.ContinueOnError)
cmdFlags.Usage = func() { c.Ui.Output(c.Help()) }
cmdFlags.StringVar(&c.conf.datacenter, "datacenter", "", "")
cmdFlags.StringVar(&c.conf.node, "node", "", "")
cmdFlags.StringVar(&c.conf.service, "service", "", "")
cmdFlags.StringVar(&c.conf.tag, "tag", "", "")
cmdFlags.StringVar(&c.conf.prefix, "prefix", rExecPrefix, "")
cmdFlags.DurationVar(&c.conf.replWait, "wait-repl", rExecReplicationWait, "")
cmdFlags.DurationVar(&c.conf.wait, "wait", rExecQuietWait, "")
cmdFlags.BoolVar(&c.conf.verbose, "verbose", false, "")
httpAddr := HTTPAddrFlag(cmdFlags)
if err := cmdFlags.Parse(args); err != nil {
return 1
}
// Join the commands to execute
c.conf.cmd = strings.Join(cmdFlags.Args(), " ")
// If there is no command, read stdin for a script input
if c.conf.cmd == "-" {
c.conf.cmd = ""
var buf bytes.Buffer
_, err := io.Copy(&buf, os.Stdin)
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to read stdin: %v", err))
c.Ui.Error("")
c.Ui.Error(c.Help())
return 1
}
c.conf.script = buf.Bytes()
}
// Ensure we have a command or script
if c.conf.cmd == "" && len(c.conf.script) == 0 {
c.Ui.Error("Must specify a command to execute")
c.Ui.Error("")
c.Ui.Error(c.Help())
return 1
}
// Validate the configuration
if err := c.conf.validate(); err != nil {
c.Ui.Error(err.Error())
return 1
}
// Create and test the HTTP client
client, err := HTTPClientDC(*httpAddr, c.conf.datacenter)
if err != nil {
c.Ui.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err))
return 1
}
_, err = client.Agent().NodeName()
if err != nil {
c.Ui.Error(fmt.Sprintf("Error querying Consul agent: %s", err))
return 1
}
c.client = client
// Create the job spec
spec, err := c.makeRExecSpec()
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to create job spec: %s", err))
return 1
}
// Create a session for this
c.sessionID, err = c.createSession()
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to create session: %s", err))
return 1
}
defer c.destroySession()
if c.conf.verbose {
c.Ui.Info(fmt.Sprintf("Created remote execution session: %s", c.sessionID))
}
// Upload the payload
if err := c.uploadPayload(spec); err != nil {
c.Ui.Error(fmt.Sprintf("Failed to create job file: %s", err))
return 1
}
defer c.destroyData()
if c.conf.verbose {
c.Ui.Info(fmt.Sprintf("Uploaded remote execution spec"))
}
// Wait for replication. This is done so that when the event is
// received, the job file can be read using a stale read. If the
// stale read fails, we expect a consistent read to be done, so
// largely this is a heuristic.
select {
case <-time.After(c.conf.replWait):
case <-c.ShutdownCh:
return 1
}
// Fire the event
id, err := c.fireEvent()
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to fire event: %s", err))
return 1
}
if c.conf.verbose {
c.Ui.Info(fmt.Sprintf("Fired remote execution event: %s", id))
}
// Wait for the job to finish now
return c.waitForJob()
}
// waitForJob is used to poll for results and wait until the job is terminated
func (c *ExecCommand) waitForJob() int {
// Although the session destroy is already deferred, we do it again here,
// because invalidation of the session before destroyData() ensures there is
// no race condition allowing an agent to upload data (the acquire will fail).
defer c.destroySession()
start := time.Now()
ackCh := make(chan rExecAck, 128)
heartCh := make(chan rExecHeart, 128)
outputCh := make(chan rExecOutput, 128)
exitCh := make(chan rExecExit, 128)
doneCh := make(chan struct{})
errCh := make(chan struct{}, 1)
defer close(doneCh)
go c.streamResults(doneCh, ackCh, heartCh, outputCh, exitCh, errCh)
target := &TargettedUi{Ui: c.Ui}
var ackCount, exitCount, badExit int
OUTER:
for {
// Determine wait time. We provide a larger window if we know about
// nodes which are still working.
waitIntv := c.conf.wait
if ackCount > exitCount {
waitIntv *= 2
}
select {
case e := <-ackCh:
ackCount++
if c.conf.verbose {
target.Target = e.Node
target.Info("acknowledged")
}
case h := <-heartCh:
if c.conf.verbose {
target.Target = h.Node
target.Info("heartbeat received")
}
case e := <-outputCh:
target.Target = e.Node
target.Output(string(e.Output))
case e := <-exitCh:
exitCount++
target.Target = e.Node
target.Info(fmt.Sprintf("finished with exit code %d", e.Code))
if e.Code != 0 {
badExit++
}
case <-time.After(waitIntv):
c.Ui.Info(fmt.Sprintf("%d / %d node(s) completed / acknowledged", exitCount, ackCount))
if c.conf.verbose {
c.Ui.Info(fmt.Sprintf("Completed in %0.2f seconds",
float64(time.Now().Sub(start))/float64(time.Second)))
}
break OUTER
case <-errCh:
return 1
case <-c.ShutdownCh:
return 1
}
}
if badExit > 0 {
return 2
}
return 0
}
// streamResults is used to perform blocking queries against the KV endpoint and stream in
// notice of various events into waitForJob
func (c *ExecCommand) streamResults(doneCh chan struct{}, ackCh chan rExecAck, heartCh chan rExecHeart,
outputCh chan rExecOutput, exitCh chan rExecExit, errCh chan struct{}) {
kv := c.client.KV()
opts := consulapi.QueryOptions{WaitTime: c.conf.wait}
dir := path.Join(c.conf.prefix, c.sessionID) + "/"
seen := make(map[string]struct{})
for {
// Check if we've been signaled to exit
select {
case <-doneCh:
return
default:
}
// Block on waiting for new keys
keys, qm, err := kv.Keys(dir, "", &opts)
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to read results: %s", err))
goto ERR_EXIT
}
// Fast-path the no-change case
if qm.LastIndex == opts.WaitIndex {
continue
}
opts.WaitIndex = qm.LastIndex
// Handle each key
for _, key := range keys {
// Ignore if we've seen it
if _, ok := seen[key]; ok {
continue
}
seen[key] = struct{}{}
// Trim the directory
full := key
key = strings.TrimPrefix(key, dir)
// Handle the key type
switch {
case key == rExecFileName:
continue
case strings.HasSuffix(key, rExecAckSuffix):
ackCh <- rExecAck{Node: strings.TrimSuffix(key, rExecAckSuffix)}
case strings.HasSuffix(key, rExecExitSuffix):
pair, _, err := kv.Get(full, nil)
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to read key '%s': %v", full, err))
continue
}
code, err := strconv.ParseInt(string(pair.Value), 10, 32)
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to parse exit code '%s': %v", pair.Value, err))
continue
}
exitCh <- rExecExit{
Node: strings.TrimSuffix(key, rExecExitSuffix),
Code: int(code),
}
case strings.LastIndex(key, rExecOutputDivider) != -1:
pair, _, err := kv.Get(full, nil)
if err != nil {
c.Ui.Error(fmt.Sprintf("Failed to read key '%s': %v", full, err))
continue
}
idx := strings.LastIndex(key, rExecOutputDivider)
node := key[:idx]
if len(pair.Value) == 0 {
heartCh <- rExecHeart{Node: node}
} else {
outputCh <- rExecOutput{Node: node, Output: pair.Value}
}
default:
c.Ui.Error(fmt.Sprintf("Unknown key '%s', ignoring.", key))
}
}
}
return
ERR_EXIT:
select {
case errCh <- struct{}{}:
default:
}
}
// validate checks that the configuration is sane
func (conf *rExecConf) validate() error {
// Validate the filters
if conf.node != "" {
if _, err := regexp.Compile(conf.node); err != nil {
return fmt.Errorf("Failed to compile node filter regexp: %v", err)
}
}
if conf.service != "" {
if _, err := regexp.Compile(conf.service); err != nil {
return fmt.Errorf("Failed to compile service filter regexp: %v", err)
}
}
if conf.tag != "" {
if _, err := regexp.Compile(conf.tag); err != nil {
return fmt.Errorf("Failed to compile tag filter regexp: %v", err)
}
}
if conf.tag != "" && conf.service == "" {
return fmt.Errorf("Cannot provide tag filter without service filter.")
}
return nil
}
// createSession is used to create a new session for this command
func (c *ExecCommand) createSession() (string, error) {
session := c.client.Session()
se := consulapi.SessionEntry{
Name: "Remote Exec",
}
id, _, err := session.Create(&se, nil)
return id, err
}
// destroySession is used to destroy the associated session
func (c *ExecCommand) destroySession() error {
session := c.client.Session()
_, err := session.Destroy(c.sessionID, nil)
return err
}
// makeRExecSpec creates a serialized job specification
// that can be uploaded which will be parsed by agents to
// determine what to do.
func (c *ExecCommand) makeRExecSpec() ([]byte, error) {
spec := &rExecSpec{
Command: c.conf.cmd,
Script: c.conf.script,
Wait: c.conf.wait,
}
return json.Marshal(spec)
}
// uploadPayload is used to upload the request payload
func (c *ExecCommand) uploadPayload(payload []byte) error {
kv := c.client.KV()
pair := consulapi.KVPair{
Key: path.Join(c.conf.prefix, c.sessionID, rExecFileName),
Value: payload,
Session: c.sessionID,
}
ok, _, err := kv.Acquire(&pair, nil)
if err != nil {
return err
}
if !ok {
return fmt.Errorf("failed to acquire key %s", pair.Key)
}
return nil
}
// destroyData is used to nuke all the data associated with
// this remote exec. We just do a recursive delete of our
// data directory.
func (c *ExecCommand) destroyData() error {
kv := c.client.KV()
dir := path.Join(c.conf.prefix, c.sessionID)
_, err := kv.DeleteTree(dir, nil)
return err
}
// fireEvent is used to fire the event that will notify nodes
// about the remote execution. Returns the event ID or error
func (c *ExecCommand) fireEvent() (string, error) {
// Create the user event payload
msg := &rExecEvent{
Prefix: c.conf.prefix,
Session: c.sessionID,
}
buf, err := json.Marshal(msg)
if err != nil {
return "", err
}
// Format the user event
event := c.client.Event()
params := &consulapi.UserEvent{
Name: "_rexec",
Payload: buf,
NodeFilter: c.conf.node,
ServiceFilter: c.conf.service,
TagFilter: c.conf.tag,
}
// Fire the event
id, _, err := event.Fire(params, nil)
return id, err
}
func (c *ExecCommand) Synopsis() string {
return "Executes a command on Consul nodes"
}
func (c *ExecCommand) Help() string {
helpText := `
Usage: consul exec [options] [-|command...]
Evaluates a command on remote Consul nodes. The nodes responding can
be filtered using regular expressions on node name, service, and tag
definitions. If a command is '-', stdin will be read until EOF
and used as a script input.
Options:
-http-addr=127.0.0.1:8500 HTTP address of the Consul agent.
-datacenter="" Datacenter to dispatch in. Defaults to that of agent.
-prefix="_rexec" Prefix in the KV store to use for request data
-node="" Regular expression to filter on node names
-service="" Regular expression to filter on service instances
-tag="" Regular expression to filter on service tags. Must be used
with -service.
-wait=2s Period to wait with no responses before terminating execution.
-wait-repl=200ms Period to wait for replication before firing event. This is an
optimization to allow stale reads to be performed.
-verbose Enables verbose output
`
return strings.TrimSpace(helpText)
}
// TargettedUi is a UI that wraps another UI implementation and modifies
// the output to indicate a specific target. Specifically, all Say output
// is prefixed with the target name. Message output is not prefixed but
// is offset by the length of the target so that output is lined up properly
// with Say output. Machine-readable output has the proper target set.
type TargettedUi struct {
Target string
Ui cli.Ui
}
func (u *TargettedUi) Ask(query string) (string, error) {
return u.Ui.Ask(u.prefixLines(true, query))
}
func (u *TargettedUi) Info(message string) {
u.Ui.Info(u.prefixLines(true, message))
}
func (u *TargettedUi) Output(message string) {
u.Ui.Output(u.prefixLines(false, message))
}
func (u *TargettedUi) Error(message string) {
u.Ui.Error(u.prefixLines(true, message))
}
func (u *TargettedUi) prefixLines(arrow bool, message string) string {
arrowText := "==>"
if !arrow {
arrowText = strings.Repeat(" ", len(arrowText))
}
var result bytes.Buffer
for _, line := range strings.Split(message, "\n") {
result.WriteString(fmt.Sprintf("%s %s: %s\n", arrowText, u.Target, line))
}
return strings.TrimRightFunc(result.String(), unicode.IsSpace)
}

319
command/exec_test.go Normal file
View File

@ -0,0 +1,319 @@
package command
import (
"strings"
"testing"
"time"
"github.com/armon/consul-api"
"github.com/hashicorp/consul/testutil"
"github.com/mitchellh/cli"
)
func TestExecCommand_implements(t *testing.T) {
var _ cli.Command = &ExecCommand{}
}
func TestExecCommandRun(t *testing.T) {
a1 := testAgent(t)
defer a1.Shutdown()
waitForLeader(t, a1.httpAddr)
ui := new(cli.MockUi)
c := &ExecCommand{Ui: ui}
args := []string{"-http-addr=" + a1.httpAddr, "-wait=400ms", "uptime"}
code := c.Run(args)
if code != 0 {
t.Fatalf("bad: %d. %#v", code, ui.ErrorWriter.String())
}
if !strings.Contains(ui.OutputWriter.String(), "load") {
t.Fatalf("bad: %#v", ui.OutputWriter.String())
}
}
func waitForLeader(t *testing.T, httpAddr string) {
client, err := HTTPClient(httpAddr)
if err != nil {
t.Fatalf("err: %v", err)
}
testutil.WaitForResult(func() (bool, error) {
_, qm, err := client.Catalog().Nodes(nil)
if err != nil {
return false, err
}
return qm.KnownLeader, nil
}, func(err error) {
t.Fatalf("failed to find leader: %v", err)
})
}
func TestExecCommand_Validate(t *testing.T) {
conf := &rExecConf{}
err := conf.validate()
if err != nil {
t.Fatalf("err: %v", err)
}
conf.node = "("
err = conf.validate()
if err == nil {
t.Fatalf("err: %v", err)
}
conf.node = ""
conf.service = "("
err = conf.validate()
if err == nil {
t.Fatalf("err: %v", err)
}
conf.service = "()"
conf.tag = "("
err = conf.validate()
if err == nil {
t.Fatalf("err: %v", err)
}
conf.service = ""
conf.tag = "foo"
err = conf.validate()
if err == nil {
t.Fatalf("err: %v", err)
}
}
func TestExecCommand_Sessions(t *testing.T) {
a1 := testAgent(t)
defer a1.Shutdown()
waitForLeader(t, a1.httpAddr)
client, err := HTTPClient(a1.httpAddr)
if err != nil {
t.Fatalf("err: %v", err)
}
ui := new(cli.MockUi)
c := &ExecCommand{
Ui: ui,
client: client,
}
id, err := c.createSession()
if err != nil {
t.Fatalf("err: %v", err)
}
se, _, err := client.Session().Info(id, nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if se == nil || se.Name != "Remote Exec" {
t.Fatalf("bad: %v", se)
}
c.sessionID = id
err = c.destroySession()
if err != nil {
t.Fatalf("err: %v", err)
}
se, _, err = client.Session().Info(id, nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if se != nil {
t.Fatalf("bad: %v", se)
}
}
func TestExecCommand_UploadDestroy(t *testing.T) {
a1 := testAgent(t)
defer a1.Shutdown()
waitForLeader(t, a1.httpAddr)
client, err := HTTPClient(a1.httpAddr)
if err != nil {
t.Fatalf("err: %v", err)
}
ui := new(cli.MockUi)
c := &ExecCommand{
Ui: ui,
client: client,
}
id, err := c.createSession()
if err != nil {
t.Fatalf("err: %v", err)
}
c.sessionID = id
c.conf.prefix = "_rexec"
c.conf.cmd = "uptime"
c.conf.wait = time.Second
buf, err := c.makeRExecSpec()
if err != nil {
t.Fatalf("err: %v", err)
}
err = c.uploadPayload(buf)
if err != nil {
t.Fatalf("err: %v", err)
}
pair, _, err := client.KV().Get("_rexec/"+id+"/job", nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if pair == nil || len(pair.Value) == 0 {
t.Fatalf("missing job spec")
}
err = c.destroyData()
if err != nil {
t.Fatalf("err: %v", err)
}
pair, _, err = client.KV().Get("_rexec/"+id+"/job", nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if pair != nil {
t.Fatalf("should be destroyed")
}
}
func TestExecCommand_StreamResults(t *testing.T) {
a1 := testAgent(t)
defer a1.Shutdown()
waitForLeader(t, a1.httpAddr)
client, err := HTTPClient(a1.httpAddr)
if err != nil {
t.Fatalf("err: %v", err)
}
ui := new(cli.MockUi)
c := &ExecCommand{
Ui: ui,
client: client,
}
c.conf.prefix = "_rexec"
id, err := c.createSession()
if err != nil {
t.Fatalf("err: %v", err)
}
c.sessionID = id
ackCh := make(chan rExecAck, 128)
heartCh := make(chan rExecHeart, 128)
outputCh := make(chan rExecOutput, 128)
exitCh := make(chan rExecExit, 128)
doneCh := make(chan struct{})
errCh := make(chan struct{}, 1)
defer close(doneCh)
go c.streamResults(doneCh, ackCh, heartCh, outputCh, exitCh, errCh)
prefix := "_rexec/" + id + "/"
ok, _, err := client.KV().Acquire(&consulapi.KVPair{
Key: prefix + "foo/ack",
Session: id,
}, nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if !ok {
t.Fatalf("should be ok bro")
}
select {
case a := <-ackCh:
if a.Node != "foo" {
t.Fatalf("bad: %#v", a)
}
case <-time.After(50 * time.Millisecond):
t.Fatalf("timeout")
}
ok, _, err = client.KV().Acquire(&consulapi.KVPair{
Key: prefix + "foo/exit",
Value: []byte("127"),
Session: id,
}, nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if !ok {
t.Fatalf("should be ok bro")
}
select {
case e := <-exitCh:
if e.Node != "foo" || e.Code != 127 {
t.Fatalf("bad: %#v", e)
}
case <-time.After(50 * time.Millisecond):
t.Fatalf("timeout")
}
// Random key, should ignore
ok, _, err = client.KV().Acquire(&consulapi.KVPair{
Key: prefix + "foo/random",
Session: id,
}, nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if !ok {
t.Fatalf("should be ok bro")
}
// Output heartbeat
ok, _, err = client.KV().Acquire(&consulapi.KVPair{
Key: prefix + "foo/out/00000",
Session: id,
}, nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if !ok {
t.Fatalf("should be ok bro")
}
select {
case h := <-heartCh:
if h.Node != "foo" {
t.Fatalf("bad: %#v", h)
}
case <-time.After(50 * time.Millisecond):
t.Fatalf("timeout")
}
// Output value
ok, _, err = client.KV().Acquire(&consulapi.KVPair{
Key: prefix + "foo/out/00001",
Value: []byte("test"),
Session: id,
}, nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if !ok {
t.Fatalf("should be ok bro")
}
select {
case o := <-outputCh:
if o.Node != "foo" || string(o.Output) != "test" {
t.Fatalf("bad: %#v", o)
}
case <-time.After(50 * time.Millisecond):
t.Fatalf("timeout")
}
}

View File

@ -27,7 +27,13 @@ func HTTPAddrFlag(f *flag.FlagSet) *string {
// HTTPClient returns a new Consul HTTP client with the given address.
func HTTPClient(addr string) (*consulapi.Client, error) {
return HTTPClientDC(addr, "")
}
// HTTPClientDC returns a new Consul HTTP client with the given address and datacenter
func HTTPClientDC(addr, dc string) (*consulapi.Client, error) {
conf := consulapi.DefaultConfig()
conf.Address = addr
conf.Datacenter = dc
return consulapi.NewClient(conf)
}

View File

@ -31,6 +31,13 @@ func init() {
}, nil
},
"exec": func() (cli.Command, error) {
return &command.ExecCommand{
ShutdownCh: makeShutdownCh(),
Ui: ui,
}, nil
},
"force-leave": func() (cli.Command, error) {
return &command.ForceLeaveCommand{
Ui: ui,

View File

@ -1209,7 +1209,8 @@ can be specified using the "?dc=" query parameter.
The fire endpoint expects a PUT request, with an optional body.
The body contents are opaque to Consul, and become the "payload"
of the event.
of the event. Any names starting with the "_" prefix should be considered
reserved, and for Consul's internal use.
The `?node=`, `?service=`, and `?tag=` query parameters may optionally
be provided. They respectively provide a regular expression to filter

View File

@ -227,6 +227,9 @@ definitions support being updated during a reload.
* `data_dir` - Equivalent to the `-data-dir` command-line flag.
* `disable_remote_exec` - Disables support for remote execution. When set to true,
the agent will ignore any incoming remote exec requests.
* `dns_config` - This object allows a number of sub-keys to be set which can tune
how DNS queries are perfomed. See this guide on [DNS caching](/docs/guides/dns-cache.html).
The following sub-keys are available:

View File

@ -0,0 +1,62 @@
---
layout: "docs"
page_title: "Commands: Exec"
sidebar_current: "docs-commands-exec"
---
# Consul Exec
Command: `consul exec`
The exec command provides a mechahanism for remote execution. For example,
this can be used to run the `uptime` command across all machines providing
the `web` service.
Remote execution works by specifying a job which is stored in the KV store.
Agent's are informed about the new job using the [event system](/docs/commands/event.html),
which propogates messages via the [gossip protocol](/docs/internals/gossip.html).
As a result, delivery is best-effort, and there is **no guarantee** of execution.
While events are purely gossip driven, remote execution relies on the KV store
as a message broker. As a result, the `exec` command will not be able to
properly function during a Consul outage.
## Usage
Usage: `consul exec [options] [-|command...]`
The only required option is a command to execute. This is either given
as trailing arguments, or by specifying '-', stdin will be read to
completion as a script to evaluate.
The list of available flags are:
* `-http-addr` - Address to the HTTP server of the agent you want to contact
to send this command. If this isn't specified, the command will contact
"127.0.0.1:8500" which is the default HTTP address of a Consul agent.
* `-datacenter` - Datacenter to query. Defaults to that of agent. In version
0.4, that is the only supported value.
* `-prefix` - Key prefix in the KV store to use for storing request data.
Defaults to "_rexec".
* `-node` - Regular expression to filter nodes which should evaluate the event.
* `-service` - Regular expression to filter to only nodes with matching services.
* `-tag` - Regular expression to filter to only nodes with a service that has
a matching tag. This must be used with `-service`. As an example, you may
do "-server mysql -tag slave".
* `-wait` - Specifies the period of time in which no agent's respond before considering
the job finished. This is basically the quiescent time required to assume completion.
This period is not a hard deadline, and the command will wait longer depending on
various heuristics.
* `-wait-repl` - Period to wait after writing the job specification for replication.
This is a heuristic value and enables agents to do a stale read of the job. Defaults
to 200msec.
* `-verbose` - Enables verbose output.

View File

@ -25,6 +25,8 @@ usage: consul [--version] [--help] <command> [<args>]
Available commands are:
agent Runs a Consul agent
event Fire a new event
exec Executes a command on Consul nodes
force-leave Forces a member of the cluster to enter the "left" state
info Provides debugging information for operators
join Tell Consul agent to join cluster

View File

@ -49,6 +49,8 @@ usage: consul [--version] [--help] <command> [<args>]
Available commands are:
agent Runs a Consul agent
event Fire a new event
exec Executes a command on Consul nodes
force-leave Forces a member of the cluster to enter the "left" state
info Provides debugging information for operators
join Tell Consul agent to join cluster
@ -56,6 +58,7 @@ Available commands are:
leave Gracefully leaves the Consul cluster and shuts down
members Lists the members of a Consul cluster
monitor Stream logs from a Consul agent
reload Triggers the agent to reload configuration files
version Prints the Consul version
watch Watch for changes in Consul
```

View File

@ -61,6 +61,10 @@
<li<%= sidebar_current("docs-commands-event") %>>
<a href="/docs/commands/event.html">event</a>
</li>
<li<%= sidebar_current("docs-commands-exec") %>>
<a href="/docs/commands/exec.html">exec</a>
</li>
<li<%= sidebar_current("docs-commands-forceleave") %>>