AUTH-2587 add config watcher and reload logic for access client forwarder

This commit is contained in:
Dalton 2020-04-13 12:22:00 -05:00
parent 976eb24883
commit 41c358147c
32 changed files with 2929 additions and 8 deletions

View File

@ -73,17 +73,24 @@ func StartClient(conn Connection, stream io.ReadWriter, options *StartOptions) e
// `Serve` always closes `listener`.
func Serve(remoteConn Connection, listener net.Listener, shutdownC <-chan struct{}, options *StartOptions) error {
defer listener.Close()
for {
select {
case <-shutdownC:
return nil
default:
errChan := make(chan error)
go func() {
for {
conn, err := listener.Accept()
if err != nil {
return err
errChan <- err
return
}
go serveConnection(remoteConn, conn, options)
}
}()
select {
case <-shutdownC:
return nil
case err := <-errChan:
return err
}
}

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@ -12,6 +12,32 @@ import (
cli "gopkg.in/urfave/cli.v2"
)
// StartForwarder starts a client side websocket forward
func StartForwarder(forwarder config.Forwarder, shutdown <-chan struct{}) error {
validURLString, err := validation.ValidateUrl(forwarder.Listener)
if err != nil {
logger.WithError(err).Error("Error validating origin URL")
return errors.Wrap(err, "error validating origin URL")
}
validURL, err := url.Parse(validURLString)
if err != nil {
logger.WithError(err).Error("Error parsing origin URL")
return errors.Wrap(err, "error parsing origin URL")
}
options := &carrier.StartOptions{
OriginURL: forwarder.URL,
Headers: make(http.Header), //TODO: TUN-2688 support custom headers from config file
}
// we could add a cmd line variable for this bool if we want the SOCK5 server to be on the client side
wsConn := carrier.NewWSConnection(logger, false)
logger.Infof("Start Websocket listener on: %s", validURL.Host)
return carrier.StartForwarder(wsConn, validURL.Host, shutdown, options)
}
// ssh will start a WS proxy server for server mode
// or copy from stdin/stdout for client mode
// useful for proxying other protocols (like ssh) over websockets

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@ -0,0 +1,112 @@
package main
import (
"github.com/cloudflare/cloudflared/cmd/cloudflared/access"
"github.com/cloudflare/cloudflared/cmd/cloudflared/config"
"github.com/sirupsen/logrus"
)
type forwarderState struct {
forwarder config.Forwarder
shutdown chan struct{}
}
func (s *forwarderState) Shutdown() {
s.shutdown <- struct{}{}
}
// AppService is the main service that runs when no command lines flags are passed to cloudflared
// it manages all the running services such as tunnels, forwarders, DNS resolver, etc
type AppService struct {
configManager config.Manager
shutdownC chan struct{}
forwarders map[string]forwarderState
configUpdateChan chan config.Root
logger *logrus.Logger
}
// NewAppService creates a new AppService with needed supporting services
func NewAppService(configManager config.Manager, shutdownC chan struct{}, logger *logrus.Logger) *AppService {
return &AppService{
configManager: configManager,
shutdownC: shutdownC,
forwarders: make(map[string]forwarderState),
configUpdateChan: make(chan config.Root),
logger: logger,
}
}
// Run starts the run loop to handle config updates and run forwarders, tunnels, etc
func (s *AppService) Run() error {
go s.actionLoop()
return s.configManager.Start(s)
}
// Shutdown kills all the running services
func (s *AppService) Shutdown() error {
s.configManager.Shutdown()
return nil
}
// ConfigDidUpdate is a delegate notification from the config manager
// it is trigger when the config file has been updated and now the service needs
// to update its services accordingly
func (s *AppService) ConfigDidUpdate(c config.Root) {
s.configUpdateChan <- c
}
// actionLoop handles the actions from running processes
func (s *AppService) actionLoop() {
for {
select {
case c := <-s.configUpdateChan:
s.handleConfigUpdate(c)
case <-s.shutdownC:
for _, state := range s.forwarders {
state.Shutdown()
}
return
}
}
}
func (s *AppService) handleConfigUpdate(c config.Root) {
// handle the client forward listeners
activeListeners := map[string]struct{}{}
for _, f := range c.Forwarders {
s.handleForwarderUpdate(f)
activeListeners[f.Listener] = struct{}{}
}
// remove any listeners that are no longer active
for key, state := range s.forwarders {
if _, ok := activeListeners[key]; !ok {
state.Shutdown()
delete(s.forwarders, key)
}
}
// TODO: AUTH-2588, TUN-1451 - tunnels and dns proxy
}
// handle managing a forwarder service
func (s *AppService) handleForwarderUpdate(f config.Forwarder) {
// check if we need to start a new listener or stop an old one
if state, ok := s.forwarders[f.Listener]; ok {
if state.forwarder.Hash() == f.Hash() {
return // the exact same listener, no changes, so move along
}
state.Shutdown() //shutdown the listener since a new one is starting
}
// add a new forwarder to the list
state := forwarderState{forwarder: f, shutdown: make(chan struct{}, 1)}
s.forwarders[f.Listener] = state
// start the forwarder
go func(f forwarderState) {
err := access.StartForwarder(f.forwarder, f.shutdown)
if err != nil {
s.logger.WithError(err).Errorf("Forwarder at address: %s", f.forwarder)
}
}(state)
}

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@ -0,0 +1,101 @@
package config
import (
"errors"
"os"
"github.com/cloudflare/cloudflared/watcher"
"github.com/sirupsen/logrus"
"gopkg.in/yaml.v2"
)
// Notifier sends out config updates
type Notifier interface {
ConfigDidUpdate(Root)
}
// Manager is the base functions of the config manager
type Manager interface {
Start(Notifier) error
Shutdown()
}
// FileManager watches the yaml config for changes
// sends updates to the service to reconfigure to match the updated config
type FileManager struct {
watcher watcher.Notifier
notifier Notifier
configPath string
logger *logrus.Logger
}
// NewFileManager creates a config manager
func NewFileManager(watcher watcher.Notifier, configPath string, logger *logrus.Logger) (Manager, error) {
m := &FileManager{
watcher: watcher,
configPath: configPath,
logger: logger,
}
err := watcher.Add(configPath)
return m, err
}
// Start starts the runloop to watch for config changes
func (m *FileManager) Start(notifier Notifier) error {
m.notifier = notifier
// update the notifier with a fresh config on start
config, err := m.GetConfig()
if err != nil {
return err
}
notifier.ConfigDidUpdate(config)
m.watcher.Start(m)
return nil
}
// GetConfig reads the yaml file from the disk
func (m *FileManager) GetConfig() (Root, error) {
if m.configPath == "" {
return Root{}, errors.New("unable to find config file")
}
file, err := os.Open(m.configPath)
if err != nil {
return Root{}, err
}
defer file.Close()
var config Root
if err := yaml.NewDecoder(file).Decode(&config); err != nil {
return Root{}, err
}
return config, nil
}
// Shutdown stops the watcher
func (m *FileManager) Shutdown() {
m.watcher.Shutdown()
}
// File change notifications from the watcher
// WatcherItemDidChange triggers when the yaml config is updated
// sends the updated config to the service to reload its state
func (m *FileManager) WatcherItemDidChange(filepath string) {
config, err := m.GetConfig()
if err != nil {
m.logger.WithError(err).Error("Failed to read new config")
return
}
m.logger.Info("Config file has been updated")
m.notifier.ConfigDidUpdate(config)
}
// WatcherDidError notifies of errors with the file watcher
func (m *FileManager) WatcherDidError(err error) {
m.logger.WithError(err).Error("Config watcher encountered an error")
}

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@ -0,0 +1,80 @@
package config
import (
"bufio"
"os"
"testing"
"time"
"github.com/cloudflare/cloudflared/log"
"github.com/cloudflare/cloudflared/watcher"
"github.com/stretchr/testify/assert"
"gopkg.in/yaml.v2"
)
type mockNotifier struct {
configs []Root
}
func (n *mockNotifier) ConfigDidUpdate(c Root) {
n.configs = append(n.configs, c)
}
func writeConfig(t *testing.T, f *os.File, c *Root) {
f.Sync()
b, err := yaml.Marshal(c)
assert.NoError(t, err)
w := bufio.NewWriter(f)
_, err = w.Write(b)
assert.NoError(t, err)
err = w.Flush()
assert.NoError(t, err)
}
func TestConfigChanged(t *testing.T) {
filePath := "config.yaml"
f, err := os.Create(filePath)
assert.NoError(t, err)
defer func() {
f.Close()
os.Remove(filePath)
}()
c := &Root{
OrgKey: "abcd",
ConfigType: "mytype",
CheckinInterval: 1,
Forwarders: []Forwarder{
{
URL: "test.daltoniam.com",
Listener: "127.0.0.1:8080",
},
},
}
writeConfig(t, f, c)
w, err := watcher.NewFile()
assert.NoError(t, err)
logger := log.CreateLogger()
service, err := NewFileManager(w, filePath, logger)
assert.NoError(t, err)
n := &mockNotifier{}
go service.Start(n)
c.Forwarders = append(c.Forwarders, Forwarder{URL: "add.daltoniam.com", Listener: "127.0.0.1:8081"})
writeConfig(t, f, c)
// give it time to trigger
time.Sleep(10 * time.Millisecond)
service.Shutdown()
assert.Len(t, n.configs, 2, "did not get 2 config updates as expected")
assert.Len(t, n.configs[0].Forwarders, 1, "not the amount of forwarders expected")
assert.Len(t, n.configs[1].Forwarders, 2, "not the amount of forwarders expected")
assert.Equal(t, n.configs[0].Forwarders[0].Hash(), c.Forwarders[0].Hash(), "forwarder hashes don't match")
assert.Equal(t, n.configs[1].Forwarders[0].Hash(), c.Forwarders[0].Hash(), "forwarder hashes don't match")
assert.Equal(t, n.configs[1].Forwarders[1].Hash(), c.Forwarders[1].Hash(), "forwarder hashes don't match")
}

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@ -0,0 +1,37 @@
package config
import (
"crypto/md5"
"fmt"
"io"
)
// Forwarder represents a client side listener to forward traffic to the edge
type Forwarder struct {
URL string `json:"url"`
Listener string `json:"listener"`
}
// Tunnel represents a tunnel that should be started
type Tunnel struct {
URL string `json:"url"`
Origin string `json:"origin"`
ProtocolType string `json:"type"`
}
// Root is the base options to configure the service
type Root struct {
OrgKey string `json:"org_key"`
ConfigType string `json:"type"`
CheckinInterval int `json:"checkin_interval"`
Forwarders []Forwarder `json:"forwarders,omitempty"`
Tunnels []Tunnel `json:"tunnels,omitempty"`
}
// Hash returns the computed values to see if the forwarder values change
func (f *Forwarder) Hash() string {
h := md5.New()
io.WriteString(h, f.URL)
io.WriteString(h, f.Listener)
return fmt.Sprintf("%x", h.Sum(nil))
}

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@ -6,10 +6,12 @@ import (
"time"
"github.com/cloudflare/cloudflared/cmd/cloudflared/access"
"github.com/cloudflare/cloudflared/cmd/cloudflared/config"
"github.com/cloudflare/cloudflared/cmd/cloudflared/tunnel"
"github.com/cloudflare/cloudflared/cmd/cloudflared/updater"
"github.com/cloudflare/cloudflared/log"
"github.com/cloudflare/cloudflared/metrics"
"github.com/cloudflare/cloudflared/watcher"
raven "github.com/getsentry/raven-go"
homedir "github.com/mitchellh/go-homedir"
@ -121,7 +123,7 @@ func isEmptyInvocation(c *cli.Context) bool {
func action(version string, shutdownC, graceShutdownC chan struct{}) cli.ActionFunc {
return func(c *cli.Context) (err error) {
if isEmptyInvocation(c) {
cli.ShowAppHelpAndExit(c, 1)
return handleServiceMode(shutdownC)
}
tags := make(map[string]string)
tags["hostname"] = c.String("hostname")
@ -161,3 +163,27 @@ func handleError(err error) {
}
raven.CaptureError(err, nil)
}
// cloudflared was started without any flags
func handleServiceMode(shutdownC chan struct{}) error {
// start the main run loop that reads from the config file
f, err := watcher.NewFile()
if err != nil {
logger.WithError(err).Error("Cannot load config file")
return err
}
configPath := config.FindDefaultConfigPath()
configManager, err := config.NewFileManager(f, configPath, logger)
if err != nil {
logger.WithError(err).Error("Cannot setup config file for monitoring")
return err
}
appService := NewAppService(configManager, shutdownC, logger)
if err := appService.Run(); err != nil {
logger.WithError(err).Error("Failed to start app service")
return err
}
return nil
}

3
go.mod
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@ -21,6 +21,7 @@ require (
github.com/facebookgo/stack v0.0.0-20160209184415-751773369052 // indirect
github.com/facebookgo/subset v0.0.0-20150612182917-8dac2c3c4870 // indirect
github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 // indirect
github.com/fsnotify/fsnotify v1.4.9
github.com/getsentry/raven-go v0.0.0-20180517221441-ed7bcb39ff10
github.com/gliderlabs/ssh v0.0.0-20191009160644-63518b5243e0
github.com/go-sql-driver/mysql v1.4.1
@ -67,7 +68,7 @@ require (
gopkg.in/coreos/go-oidc.v2 v2.1.0
gopkg.in/square/go-jose.v2 v2.4.0 // indirect
gopkg.in/urfave/cli.v2 v2.0.0-20180128181224-d604b6ffeee8
gopkg.in/yaml.v2 v2.2.4 // indirect
gopkg.in/yaml.v2 v2.2.4
zombiezen.com/go/capnproto2 v0.0.0-20180616160808-7cfd211c19c7
)

3
go.sum
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@ -48,6 +48,8 @@ github.com/facebookgo/subset v0.0.0-20150612182917-8dac2c3c4870 h1:E2s37DuLxFhQD
github.com/facebookgo/subset v0.0.0-20150612182917-8dac2c3c4870/go.mod h1:5tD+neXqOorC30/tWg0LCSkrqj/AR6gu8yY8/fpw1q0=
github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 h1:BHsljHzVlRcyQhjrss6TZTdY2VfCqZPbv5k3iBFa2ZQ=
github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI435gkrCt3MPfRiAkVrwSbHsst4LCFVfpJc=
github.com/fsnotify/fsnotify v1.4.9 h1:hsms1Qyu0jgnwNXIxa+/V/PDsU6CfLf6CNO8H7IWoS4=
github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
github.com/getsentry/raven-go v0.0.0-20180517221441-ed7bcb39ff10 h1:YO10pIIBftO/kkTFdWhctH96grJ7qiy7bMdiZcIvPKs=
github.com/getsentry/raven-go v0.0.0-20180517221441-ed7bcb39ff10/go.mod h1:KungGk8q33+aIAZUIVWZDr2OfAEBsO49PX4NzFV5kcQ=
github.com/gliderlabs/ssh v0.0.0-20191009160644-63518b5243e0 h1:gF8ngtda767ddth2SH0YSAhswhz6qUkvyI9EZFYCWJA=
@ -188,6 +190,7 @@ golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5h
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20190924154521-2837fb4f24fe/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20191008105621-543471e840be h1:QAcqgptGM8IQBC9K/RC4o+O9YmqEm0diQn9QmZw/0mU=
golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20191020212454-3e7259c5e7c2 h1:nq114VpM8lsSlP+lyUbANecYHYiFcSNFtqcBlxRV+gA=

12
vendor/github.com/fsnotify/fsnotify/.editorconfig generated vendored Normal file
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@ -0,0 +1,12 @@
root = true
[*.go]
indent_style = tab
indent_size = 4
insert_final_newline = true
[*.{yml,yaml}]
indent_style = space
indent_size = 2
insert_final_newline = true
trim_trailing_whitespace = true

1
vendor/github.com/fsnotify/fsnotify/.gitattributes generated vendored Normal file
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@ -0,0 +1 @@
go.sum linguist-generated

6
vendor/github.com/fsnotify/fsnotify/.gitignore generated vendored Normal file
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@ -0,0 +1,6 @@
# Setup a Global .gitignore for OS and editor generated files:
# https://help.github.com/articles/ignoring-files
# git config --global core.excludesfile ~/.gitignore_global
.vagrant
*.sublime-project

36
vendor/github.com/fsnotify/fsnotify/.travis.yml generated vendored Normal file
View File

@ -0,0 +1,36 @@
sudo: false
language: go
go:
- "stable"
- "1.11.x"
- "1.10.x"
- "1.9.x"
matrix:
include:
- go: "stable"
env: GOLINT=true
allow_failures:
- go: tip
fast_finish: true
before_install:
- if [ ! -z "${GOLINT}" ]; then go get -u golang.org/x/lint/golint; fi
script:
- go test --race ./...
after_script:
- test -z "$(gofmt -s -l -w . | tee /dev/stderr)"
- if [ ! -z "${GOLINT}" ]; then echo running golint; golint --set_exit_status ./...; else echo skipping golint; fi
- go vet ./...
os:
- linux
- osx
- windows
notifications:
email: false

52
vendor/github.com/fsnotify/fsnotify/AUTHORS generated vendored Normal file
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@ -0,0 +1,52 @@
# Names should be added to this file as
# Name or Organization <email address>
# The email address is not required for organizations.
# You can update this list using the following command:
#
# $ git shortlog -se | awk '{print $2 " " $3 " " $4}'
# Please keep the list sorted.
Aaron L <aaron@bettercoder.net>
Adrien Bustany <adrien@bustany.org>
Amit Krishnan <amit.krishnan@oracle.com>
Anmol Sethi <me@anmol.io>
Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com>
Bruno Bigras <bigras.bruno@gmail.com>
Caleb Spare <cespare@gmail.com>
Case Nelson <case@teammating.com>
Chris Howey <chris@howey.me> <howeyc@gmail.com>
Christoffer Buchholz <christoffer.buchholz@gmail.com>
Daniel Wagner-Hall <dawagner@gmail.com>
Dave Cheney <dave@cheney.net>
Evan Phoenix <evan@fallingsnow.net>
Francisco Souza <f@souza.cc>
Hari haran <hariharan.uno@gmail.com>
John C Barstow
Kelvin Fo <vmirage@gmail.com>
Ken-ichirou MATSUZAWA <chamas@h4.dion.ne.jp>
Matt Layher <mdlayher@gmail.com>
Nathan Youngman <git@nathany.com>
Nickolai Zeldovich <nickolai@csail.mit.edu>
Patrick <patrick@dropbox.com>
Paul Hammond <paul@paulhammond.org>
Pawel Knap <pawelknap88@gmail.com>
Pieter Droogendijk <pieter@binky.org.uk>
Pursuit92 <JoshChase@techpursuit.net>
Riku Voipio <riku.voipio@linaro.org>
Rob Figueiredo <robfig@gmail.com>
Rodrigo Chiossi <rodrigochiossi@gmail.com>
Slawek Ligus <root@ooz.ie>
Soge Zhang <zhssoge@gmail.com>
Tiffany Jernigan <tiffany.jernigan@intel.com>
Tilak Sharma <tilaks@google.com>
Tom Payne <twpayne@gmail.com>
Travis Cline <travis.cline@gmail.com>
Tudor Golubenco <tudor.g@gmail.com>
Vahe Khachikyan <vahe@live.ca>
Yukang <moorekang@gmail.com>
bronze1man <bronze1man@gmail.com>
debrando <denis.brandolini@gmail.com>
henrikedwards <henrik.edwards@gmail.com>
铁哥 <guotie.9@gmail.com>

317
vendor/github.com/fsnotify/fsnotify/CHANGELOG.md generated vendored Normal file
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@ -0,0 +1,317 @@
# Changelog
## v1.4.7 / 2018-01-09
* BSD/macOS: Fix possible deadlock on closing the watcher on kqueue (thanks @nhooyr and @glycerine)
* Tests: Fix missing verb on format string (thanks @rchiossi)
* Linux: Fix deadlock in Remove (thanks @aarondl)
* Linux: Watch.Add improvements (avoid race, fix consistency, reduce garbage) (thanks @twpayne)
* Docs: Moved FAQ into the README (thanks @vahe)
* Linux: Properly handle inotify's IN_Q_OVERFLOW event (thanks @zeldovich)
* Docs: replace references to OS X with macOS
## v1.4.2 / 2016-10-10
* Linux: use InotifyInit1 with IN_CLOEXEC to stop leaking a file descriptor to a child process when using fork/exec [#178](https://github.com/fsnotify/fsnotify/pull/178) (thanks @pattyshack)
## v1.4.1 / 2016-10-04
* Fix flaky inotify stress test on Linux [#177](https://github.com/fsnotify/fsnotify/pull/177) (thanks @pattyshack)
## v1.4.0 / 2016-10-01
* add a String() method to Event.Op [#165](https://github.com/fsnotify/fsnotify/pull/165) (thanks @oozie)
## v1.3.1 / 2016-06-28
* Windows: fix for double backslash when watching the root of a drive [#151](https://github.com/fsnotify/fsnotify/issues/151) (thanks @brunoqc)
## v1.3.0 / 2016-04-19
* Support linux/arm64 by [patching](https://go-review.googlesource.com/#/c/21971/) x/sys/unix and switching to to it from syscall (thanks @suihkulokki) [#135](https://github.com/fsnotify/fsnotify/pull/135)
## v1.2.10 / 2016-03-02
* Fix golint errors in windows.go [#121](https://github.com/fsnotify/fsnotify/pull/121) (thanks @tiffanyfj)
## v1.2.9 / 2016-01-13
kqueue: Fix logic for CREATE after REMOVE [#111](https://github.com/fsnotify/fsnotify/pull/111) (thanks @bep)
## v1.2.8 / 2015-12-17
* kqueue: fix race condition in Close [#105](https://github.com/fsnotify/fsnotify/pull/105) (thanks @djui for reporting the issue and @ppknap for writing a failing test)
* inotify: fix race in test
* enable race detection for continuous integration (Linux, Mac, Windows)
## v1.2.5 / 2015-10-17
* inotify: use epoll_create1 for arm64 support (requires Linux 2.6.27 or later) [#100](https://github.com/fsnotify/fsnotify/pull/100) (thanks @suihkulokki)
* inotify: fix path leaks [#73](https://github.com/fsnotify/fsnotify/pull/73) (thanks @chamaken)
* kqueue: watch for rename events on subdirectories [#83](https://github.com/fsnotify/fsnotify/pull/83) (thanks @guotie)
* kqueue: avoid infinite loops from symlinks cycles [#101](https://github.com/fsnotify/fsnotify/pull/101) (thanks @illicitonion)
## v1.2.1 / 2015-10-14
* kqueue: don't watch named pipes [#98](https://github.com/fsnotify/fsnotify/pull/98) (thanks @evanphx)
## v1.2.0 / 2015-02-08
* inotify: use epoll to wake up readEvents [#66](https://github.com/fsnotify/fsnotify/pull/66) (thanks @PieterD)
* inotify: closing watcher should now always shut down goroutine [#63](https://github.com/fsnotify/fsnotify/pull/63) (thanks @PieterD)
* kqueue: close kqueue after removing watches, fixes [#59](https://github.com/fsnotify/fsnotify/issues/59)
## v1.1.1 / 2015-02-05
* inotify: Retry read on EINTR [#61](https://github.com/fsnotify/fsnotify/issues/61) (thanks @PieterD)
## v1.1.0 / 2014-12-12
* kqueue: rework internals [#43](https://github.com/fsnotify/fsnotify/pull/43)
* add low-level functions
* only need to store flags on directories
* less mutexes [#13](https://github.com/fsnotify/fsnotify/issues/13)
* done can be an unbuffered channel
* remove calls to os.NewSyscallError
* More efficient string concatenation for Event.String() [#52](https://github.com/fsnotify/fsnotify/pull/52) (thanks @mdlayher)
* kqueue: fix regression in rework causing subdirectories to be watched [#48](https://github.com/fsnotify/fsnotify/issues/48)
* kqueue: cleanup internal watch before sending remove event [#51](https://github.com/fsnotify/fsnotify/issues/51)
## v1.0.4 / 2014-09-07
* kqueue: add dragonfly to the build tags.
* Rename source code files, rearrange code so exported APIs are at the top.
* Add done channel to example code. [#37](https://github.com/fsnotify/fsnotify/pull/37) (thanks @chenyukang)
## v1.0.3 / 2014-08-19
* [Fix] Windows MOVED_TO now translates to Create like on BSD and Linux. [#36](https://github.com/fsnotify/fsnotify/issues/36)
## v1.0.2 / 2014-08-17
* [Fix] Missing create events on macOS. [#14](https://github.com/fsnotify/fsnotify/issues/14) (thanks @zhsso)
* [Fix] Make ./path and path equivalent. (thanks @zhsso)
## v1.0.0 / 2014-08-15
* [API] Remove AddWatch on Windows, use Add.
* Improve documentation for exported identifiers. [#30](https://github.com/fsnotify/fsnotify/issues/30)
* Minor updates based on feedback from golint.
## dev / 2014-07-09
* Moved to [github.com/fsnotify/fsnotify](https://github.com/fsnotify/fsnotify).
* Use os.NewSyscallError instead of returning errno (thanks @hariharan-uno)
## dev / 2014-07-04
* kqueue: fix incorrect mutex used in Close()
* Update example to demonstrate usage of Op.
## dev / 2014-06-28
* [API] Don't set the Write Op for attribute notifications [#4](https://github.com/fsnotify/fsnotify/issues/4)
* Fix for String() method on Event (thanks Alex Brainman)
* Don't build on Plan 9 or Solaris (thanks @4ad)
## dev / 2014-06-21
* Events channel of type Event rather than *Event.
* [internal] use syscall constants directly for inotify and kqueue.
* [internal] kqueue: rename events to kevents and fileEvent to event.
## dev / 2014-06-19
* Go 1.3+ required on Windows (uses syscall.ERROR_MORE_DATA internally).
* [internal] remove cookie from Event struct (unused).
* [internal] Event struct has the same definition across every OS.
* [internal] remove internal watch and removeWatch methods.
## dev / 2014-06-12
* [API] Renamed Watch() to Add() and RemoveWatch() to Remove().
* [API] Pluralized channel names: Events and Errors.
* [API] Renamed FileEvent struct to Event.
* [API] Op constants replace methods like IsCreate().
## dev / 2014-06-12
* Fix data race on kevent buffer (thanks @tilaks) [#98](https://github.com/howeyc/fsnotify/pull/98)
## dev / 2014-05-23
* [API] Remove current implementation of WatchFlags.
* current implementation doesn't take advantage of OS for efficiency
* provides little benefit over filtering events as they are received, but has extra bookkeeping and mutexes
* no tests for the current implementation
* not fully implemented on Windows [#93](https://github.com/howeyc/fsnotify/issues/93#issuecomment-39285195)
## v0.9.3 / 2014-12-31
* kqueue: cleanup internal watch before sending remove event [#51](https://github.com/fsnotify/fsnotify/issues/51)
## v0.9.2 / 2014-08-17
* [Backport] Fix missing create events on macOS. [#14](https://github.com/fsnotify/fsnotify/issues/14) (thanks @zhsso)
## v0.9.1 / 2014-06-12
* Fix data race on kevent buffer (thanks @tilaks) [#98](https://github.com/howeyc/fsnotify/pull/98)
## v0.9.0 / 2014-01-17
* IsAttrib() for events that only concern a file's metadata [#79][] (thanks @abustany)
* [Fix] kqueue: fix deadlock [#77][] (thanks @cespare)
* [NOTICE] Development has moved to `code.google.com/p/go.exp/fsnotify` in preparation for inclusion in the Go standard library.
## v0.8.12 / 2013-11-13
* [API] Remove FD_SET and friends from Linux adapter
## v0.8.11 / 2013-11-02
* [Doc] Add Changelog [#72][] (thanks @nathany)
* [Doc] Spotlight and double modify events on macOS [#62][] (reported by @paulhammond)
## v0.8.10 / 2013-10-19
* [Fix] kqueue: remove file watches when parent directory is removed [#71][] (reported by @mdwhatcott)
* [Fix] kqueue: race between Close and readEvents [#70][] (reported by @bernerdschaefer)
* [Doc] specify OS-specific limits in README (thanks @debrando)
## v0.8.9 / 2013-09-08
* [Doc] Contributing (thanks @nathany)
* [Doc] update package path in example code [#63][] (thanks @paulhammond)
* [Doc] GoCI badge in README (Linux only) [#60][]
* [Doc] Cross-platform testing with Vagrant [#59][] (thanks @nathany)
## v0.8.8 / 2013-06-17
* [Fix] Windows: handle `ERROR_MORE_DATA` on Windows [#49][] (thanks @jbowtie)
## v0.8.7 / 2013-06-03
* [API] Make syscall flags internal
* [Fix] inotify: ignore event changes
* [Fix] race in symlink test [#45][] (reported by @srid)
* [Fix] tests on Windows
* lower case error messages
## v0.8.6 / 2013-05-23
* kqueue: Use EVT_ONLY flag on Darwin
* [Doc] Update README with full example
## v0.8.5 / 2013-05-09
* [Fix] inotify: allow monitoring of "broken" symlinks (thanks @tsg)
## v0.8.4 / 2013-04-07
* [Fix] kqueue: watch all file events [#40][] (thanks @ChrisBuchholz)
## v0.8.3 / 2013-03-13
* [Fix] inoitfy/kqueue memory leak [#36][] (reported by @nbkolchin)
* [Fix] kqueue: use fsnFlags for watching a directory [#33][] (reported by @nbkolchin)
## v0.8.2 / 2013-02-07
* [Doc] add Authors
* [Fix] fix data races for map access [#29][] (thanks @fsouza)
## v0.8.1 / 2013-01-09
* [Fix] Windows path separators
* [Doc] BSD License
## v0.8.0 / 2012-11-09
* kqueue: directory watching improvements (thanks @vmirage)
* inotify: add `IN_MOVED_TO` [#25][] (requested by @cpisto)
* [Fix] kqueue: deleting watched directory [#24][] (reported by @jakerr)
## v0.7.4 / 2012-10-09
* [Fix] inotify: fixes from https://codereview.appspot.com/5418045/ (ugorji)
* [Fix] kqueue: preserve watch flags when watching for delete [#21][] (reported by @robfig)
* [Fix] kqueue: watch the directory even if it isn't a new watch (thanks @robfig)
* [Fix] kqueue: modify after recreation of file
## v0.7.3 / 2012-09-27
* [Fix] kqueue: watch with an existing folder inside the watched folder (thanks @vmirage)
* [Fix] kqueue: no longer get duplicate CREATE events
## v0.7.2 / 2012-09-01
* kqueue: events for created directories
## v0.7.1 / 2012-07-14
* [Fix] for renaming files
## v0.7.0 / 2012-07-02
* [Feature] FSNotify flags
* [Fix] inotify: Added file name back to event path
## v0.6.0 / 2012-06-06
* kqueue: watch files after directory created (thanks @tmc)
## v0.5.1 / 2012-05-22
* [Fix] inotify: remove all watches before Close()
## v0.5.0 / 2012-05-03
* [API] kqueue: return errors during watch instead of sending over channel
* kqueue: match symlink behavior on Linux
* inotify: add `DELETE_SELF` (requested by @taralx)
* [Fix] kqueue: handle EINTR (reported by @robfig)
* [Doc] Godoc example [#1][] (thanks @davecheney)
## v0.4.0 / 2012-03-30
* Go 1 released: build with go tool
* [Feature] Windows support using winfsnotify
* Windows does not have attribute change notifications
* Roll attribute notifications into IsModify
## v0.3.0 / 2012-02-19
* kqueue: add files when watch directory
## v0.2.0 / 2011-12-30
* update to latest Go weekly code
## v0.1.0 / 2011-10-19
* kqueue: add watch on file creation to match inotify
* kqueue: create file event
* inotify: ignore `IN_IGNORED` events
* event String()
* linux: common FileEvent functions
* initial commit
[#79]: https://github.com/howeyc/fsnotify/pull/79
[#77]: https://github.com/howeyc/fsnotify/pull/77
[#72]: https://github.com/howeyc/fsnotify/issues/72
[#71]: https://github.com/howeyc/fsnotify/issues/71
[#70]: https://github.com/howeyc/fsnotify/issues/70
[#63]: https://github.com/howeyc/fsnotify/issues/63
[#62]: https://github.com/howeyc/fsnotify/issues/62
[#60]: https://github.com/howeyc/fsnotify/issues/60
[#59]: https://github.com/howeyc/fsnotify/issues/59
[#49]: https://github.com/howeyc/fsnotify/issues/49
[#45]: https://github.com/howeyc/fsnotify/issues/45
[#40]: https://github.com/howeyc/fsnotify/issues/40
[#36]: https://github.com/howeyc/fsnotify/issues/36
[#33]: https://github.com/howeyc/fsnotify/issues/33
[#29]: https://github.com/howeyc/fsnotify/issues/29
[#25]: https://github.com/howeyc/fsnotify/issues/25
[#24]: https://github.com/howeyc/fsnotify/issues/24
[#21]: https://github.com/howeyc/fsnotify/issues/21

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# Contributing
## Issues
* Request features and report bugs using the [GitHub Issue Tracker](https://github.com/fsnotify/fsnotify/issues).
* Please indicate the platform you are using fsnotify on.
* A code example to reproduce the problem is appreciated.
## Pull Requests
### Contributor License Agreement
fsnotify is derived from code in the [golang.org/x/exp](https://godoc.org/golang.org/x/exp) package and it may be included [in the standard library](https://github.com/fsnotify/fsnotify/issues/1) in the future. Therefore fsnotify carries the same [LICENSE](https://github.com/fsnotify/fsnotify/blob/master/LICENSE) as Go. Contributors retain their copyright, so you need to fill out a short form before we can accept your contribution: [Google Individual Contributor License Agreement](https://developers.google.com/open-source/cla/individual).
Please indicate that you have signed the CLA in your pull request.
### How fsnotify is Developed
* Development is done on feature branches.
* Tests are run on BSD, Linux, macOS and Windows.
* Pull requests are reviewed and [applied to master][am] using [hub][].
* Maintainers may modify or squash commits rather than asking contributors to.
* To issue a new release, the maintainers will:
* Update the CHANGELOG
* Tag a version, which will become available through gopkg.in.
### How to Fork
For smooth sailing, always use the original import path. Installing with `go get` makes this easy.
1. Install from GitHub (`go get -u github.com/fsnotify/fsnotify`)
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Ensure everything works and the tests pass (see below)
4. Commit your changes (`git commit -am 'Add some feature'`)
Contribute upstream:
1. Fork fsnotify on GitHub
2. Add your remote (`git remote add fork git@github.com:mycompany/repo.git`)
3. Push to the branch (`git push fork my-new-feature`)
4. Create a new Pull Request on GitHub
This workflow is [thoroughly explained by Katrina Owen](https://splice.com/blog/contributing-open-source-git-repositories-go/).
### Testing
fsnotify uses build tags to compile different code on Linux, BSD, macOS, and Windows.
Before doing a pull request, please do your best to test your changes on multiple platforms, and list which platforms you were able/unable to test on.
To aid in cross-platform testing there is a Vagrantfile for Linux and BSD.
* Install [Vagrant](http://www.vagrantup.com/) and [VirtualBox](https://www.virtualbox.org/)
* Setup [Vagrant Gopher](https://github.com/nathany/vagrant-gopher) in your `src` folder.
* Run `vagrant up` from the project folder. You can also setup just one box with `vagrant up linux` or `vagrant up bsd` (note: the BSD box doesn't support Windows hosts at this time, and NFS may prompt for your host OS password)
* Once setup, you can run the test suite on a given OS with a single command `vagrant ssh linux -c 'cd fsnotify/fsnotify; go test'`.
* When you're done, you will want to halt or destroy the Vagrant boxes.
Notice: fsnotify file system events won't trigger in shared folders. The tests get around this limitation by using the /tmp directory.
Right now there is no equivalent solution for Windows and macOS, but there are Windows VMs [freely available from Microsoft](http://www.modern.ie/en-us/virtualization-tools#downloads).
### Maintainers
Help maintaining fsnotify is welcome. To be a maintainer:
* Submit a pull request and sign the CLA as above.
* You must be able to run the test suite on Mac, Windows, Linux and BSD.
To keep master clean, the fsnotify project uses the "apply mail" workflow outlined in Nathaniel Talbott's post ["Merge pull request" Considered Harmful][am]. This requires installing [hub][].
All code changes should be internal pull requests.
Releases are tagged using [Semantic Versioning](http://semver.org/).
[hub]: https://github.com/github/hub
[am]: http://blog.spreedly.com/2014/06/24/merge-pull-request-considered-harmful/#.VGa5yZPF_Zs

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Copyright (c) 2012 The Go Authors. All rights reserved.
Copyright (c) 2012-2019 fsnotify Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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# File system notifications for Go
[![GoDoc](https://godoc.org/github.com/fsnotify/fsnotify?status.svg)](https://godoc.org/github.com/fsnotify/fsnotify) [![Go Report Card](https://goreportcard.com/badge/github.com/fsnotify/fsnotify)](https://goreportcard.com/report/github.com/fsnotify/fsnotify)
fsnotify utilizes [golang.org/x/sys](https://godoc.org/golang.org/x/sys) rather than `syscall` from the standard library. Ensure you have the latest version installed by running:
```console
go get -u golang.org/x/sys/...
```
Cross platform: Windows, Linux, BSD and macOS.
| Adapter | OS | Status |
| --------------------- | -------------------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
| inotify | Linux 2.6.27 or later, Android\* | Supported [![Build Status](https://travis-ci.org/fsnotify/fsnotify.svg?branch=master)](https://travis-ci.org/fsnotify/fsnotify) |
| kqueue | BSD, macOS, iOS\* | Supported [![Build Status](https://travis-ci.org/fsnotify/fsnotify.svg?branch=master)](https://travis-ci.org/fsnotify/fsnotify) |
| ReadDirectoryChangesW | Windows | Supported [![Build Status](https://travis-ci.org/fsnotify/fsnotify.svg?branch=master)](https://travis-ci.org/fsnotify/fsnotify) |
| FSEvents | macOS | [Planned](https://github.com/fsnotify/fsnotify/issues/11) |
| FEN | Solaris 11 | [In Progress](https://github.com/fsnotify/fsnotify/issues/12) |
| fanotify | Linux 2.6.37+ | [Planned](https://github.com/fsnotify/fsnotify/issues/114) |
| USN Journals | Windows | [Maybe](https://github.com/fsnotify/fsnotify/issues/53) |
| Polling | *All* | [Maybe](https://github.com/fsnotify/fsnotify/issues/9) |
\* Android and iOS are untested.
Please see [the documentation](https://godoc.org/github.com/fsnotify/fsnotify) and consult the [FAQ](#faq) for usage information.
## API stability
fsnotify is a fork of [howeyc/fsnotify](https://godoc.org/github.com/howeyc/fsnotify) with a new API as of v1.0. The API is based on [this design document](http://goo.gl/MrYxyA).
All [releases](https://github.com/fsnotify/fsnotify/releases) are tagged based on [Semantic Versioning](http://semver.org/). Further API changes are [planned](https://github.com/fsnotify/fsnotify/milestones), and will be tagged with a new major revision number.
Go 1.6 supports dependencies located in the `vendor/` folder. Unless you are creating a library, it is recommended that you copy fsnotify into `vendor/github.com/fsnotify/fsnotify` within your project, and likewise for `golang.org/x/sys`.
## Usage
```go
package main
import (
"log"
"github.com/fsnotify/fsnotify"
)
func main() {
watcher, err := fsnotify.NewWatcher()
if err != nil {
log.Fatal(err)
}
defer watcher.Close()
done := make(chan bool)
go func() {
for {
select {
case event, ok := <-watcher.Events:
if !ok {
return
}
log.Println("event:", event)
if event.Op&fsnotify.Write == fsnotify.Write {
log.Println("modified file:", event.Name)
}
case err, ok := <-watcher.Errors:
if !ok {
return
}
log.Println("error:", err)
}
}
}()
err = watcher.Add("/tmp/foo")
if err != nil {
log.Fatal(err)
}
<-done
}
```
## Contributing
Please refer to [CONTRIBUTING][] before opening an issue or pull request.
## Example
See [example_test.go](https://github.com/fsnotify/fsnotify/blob/master/example_test.go).
## FAQ
**When a file is moved to another directory is it still being watched?**
No (it shouldn't be, unless you are watching where it was moved to).
**When I watch a directory, are all subdirectories watched as well?**
No, you must add watches for any directory you want to watch (a recursive watcher is on the roadmap [#18][]).
**Do I have to watch the Error and Event channels in a separate goroutine?**
As of now, yes. Looking into making this single-thread friendly (see [howeyc #7][#7])
**Why am I receiving multiple events for the same file on OS X?**
Spotlight indexing on OS X can result in multiple events (see [howeyc #62][#62]). A temporary workaround is to add your folder(s) to the *Spotlight Privacy settings* until we have a native FSEvents implementation (see [#11][]).
**How many files can be watched at once?**
There are OS-specific limits as to how many watches can be created:
* Linux: /proc/sys/fs/inotify/max_user_watches contains the limit, reaching this limit results in a "no space left on device" error.
* BSD / OSX: sysctl variables "kern.maxfiles" and "kern.maxfilesperproc", reaching these limits results in a "too many open files" error.
**Why don't notifications work with NFS filesystems or filesystem in userspace (FUSE)?**
fsnotify requires support from underlying OS to work. The current NFS protocol does not provide network level support for file notifications.
[#62]: https://github.com/howeyc/fsnotify/issues/62
[#18]: https://github.com/fsnotify/fsnotify/issues/18
[#11]: https://github.com/fsnotify/fsnotify/issues/11
[#7]: https://github.com/howeyc/fsnotify/issues/7
[contributing]: https://github.com/fsnotify/fsnotify/blob/master/CONTRIBUTING.md
## Related Projects
* [notify](https://github.com/rjeczalik/notify)
* [fsevents](https://github.com/fsnotify/fsevents)

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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build solaris
package fsnotify
import (
"errors"
)
// Watcher watches a set of files, delivering events to a channel.
type Watcher struct {
Events chan Event
Errors chan error
}
// NewWatcher establishes a new watcher with the underlying OS and begins waiting for events.
func NewWatcher() (*Watcher, error) {
return nil, errors.New("FEN based watcher not yet supported for fsnotify\n")
}
// Close removes all watches and closes the events channel.
func (w *Watcher) Close() error {
return nil
}
// Add starts watching the named file or directory (non-recursively).
func (w *Watcher) Add(name string) error {
return nil
}
// Remove stops watching the the named file or directory (non-recursively).
func (w *Watcher) Remove(name string) error {
return nil
}

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !plan9
// Package fsnotify provides a platform-independent interface for file system notifications.
package fsnotify
import (
"bytes"
"errors"
"fmt"
)
// Event represents a single file system notification.
type Event struct {
Name string // Relative path to the file or directory.
Op Op // File operation that triggered the event.
}
// Op describes a set of file operations.
type Op uint32
// These are the generalized file operations that can trigger a notification.
const (
Create Op = 1 << iota
Write
Remove
Rename
Chmod
)
func (op Op) String() string {
// Use a buffer for efficient string concatenation
var buffer bytes.Buffer
if op&Create == Create {
buffer.WriteString("|CREATE")
}
if op&Remove == Remove {
buffer.WriteString("|REMOVE")
}
if op&Write == Write {
buffer.WriteString("|WRITE")
}
if op&Rename == Rename {
buffer.WriteString("|RENAME")
}
if op&Chmod == Chmod {
buffer.WriteString("|CHMOD")
}
if buffer.Len() == 0 {
return ""
}
return buffer.String()[1:] // Strip leading pipe
}
// String returns a string representation of the event in the form
// "file: REMOVE|WRITE|..."
func (e Event) String() string {
return fmt.Sprintf("%q: %s", e.Name, e.Op.String())
}
// Common errors that can be reported by a watcher
var (
ErrEventOverflow = errors.New("fsnotify queue overflow")
)

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module github.com/fsnotify/fsnotify
go 1.13
require golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9

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golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9 h1:L2auWcuQIvxz9xSEqzESnV/QN/gNRXNApHi3fYwl2w0=
golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build linux
package fsnotify
import (
"errors"
"fmt"
"io"
"os"
"path/filepath"
"strings"
"sync"
"unsafe"
"golang.org/x/sys/unix"
)
// Watcher watches a set of files, delivering events to a channel.
type Watcher struct {
Events chan Event
Errors chan error
mu sync.Mutex // Map access
fd int
poller *fdPoller
watches map[string]*watch // Map of inotify watches (key: path)
paths map[int]string // Map of watched paths (key: watch descriptor)
done chan struct{} // Channel for sending a "quit message" to the reader goroutine
doneResp chan struct{} // Channel to respond to Close
}
// NewWatcher establishes a new watcher with the underlying OS and begins waiting for events.
func NewWatcher() (*Watcher, error) {
// Create inotify fd
fd, errno := unix.InotifyInit1(unix.IN_CLOEXEC)
if fd == -1 {
return nil, errno
}
// Create epoll
poller, err := newFdPoller(fd)
if err != nil {
unix.Close(fd)
return nil, err
}
w := &Watcher{
fd: fd,
poller: poller,
watches: make(map[string]*watch),
paths: make(map[int]string),
Events: make(chan Event),
Errors: make(chan error),
done: make(chan struct{}),
doneResp: make(chan struct{}),
}
go w.readEvents()
return w, nil
}
func (w *Watcher) isClosed() bool {
select {
case <-w.done:
return true
default:
return false
}
}
// Close removes all watches and closes the events channel.
func (w *Watcher) Close() error {
if w.isClosed() {
return nil
}
// Send 'close' signal to goroutine, and set the Watcher to closed.
close(w.done)
// Wake up goroutine
w.poller.wake()
// Wait for goroutine to close
<-w.doneResp
return nil
}
// Add starts watching the named file or directory (non-recursively).
func (w *Watcher) Add(name string) error {
name = filepath.Clean(name)
if w.isClosed() {
return errors.New("inotify instance already closed")
}
const agnosticEvents = unix.IN_MOVED_TO | unix.IN_MOVED_FROM |
unix.IN_CREATE | unix.IN_ATTRIB | unix.IN_MODIFY |
unix.IN_MOVE_SELF | unix.IN_DELETE | unix.IN_DELETE_SELF
var flags uint32 = agnosticEvents
w.mu.Lock()
defer w.mu.Unlock()
watchEntry := w.watches[name]
if watchEntry != nil {
flags |= watchEntry.flags | unix.IN_MASK_ADD
}
wd, errno := unix.InotifyAddWatch(w.fd, name, flags)
if wd == -1 {
return errno
}
if watchEntry == nil {
w.watches[name] = &watch{wd: uint32(wd), flags: flags}
w.paths[wd] = name
} else {
watchEntry.wd = uint32(wd)
watchEntry.flags = flags
}
return nil
}
// Remove stops watching the named file or directory (non-recursively).
func (w *Watcher) Remove(name string) error {
name = filepath.Clean(name)
// Fetch the watch.
w.mu.Lock()
defer w.mu.Unlock()
watch, ok := w.watches[name]
// Remove it from inotify.
if !ok {
return fmt.Errorf("can't remove non-existent inotify watch for: %s", name)
}
// We successfully removed the watch if InotifyRmWatch doesn't return an
// error, we need to clean up our internal state to ensure it matches
// inotify's kernel state.
delete(w.paths, int(watch.wd))
delete(w.watches, name)
// inotify_rm_watch will return EINVAL if the file has been deleted;
// the inotify will already have been removed.
// watches and pathes are deleted in ignoreLinux() implicitly and asynchronously
// by calling inotify_rm_watch() below. e.g. readEvents() goroutine receives IN_IGNORE
// so that EINVAL means that the wd is being rm_watch()ed or its file removed
// by another thread and we have not received IN_IGNORE event.
success, errno := unix.InotifyRmWatch(w.fd, watch.wd)
if success == -1 {
// TODO: Perhaps it's not helpful to return an error here in every case.
// the only two possible errors are:
// EBADF, which happens when w.fd is not a valid file descriptor of any kind.
// EINVAL, which is when fd is not an inotify descriptor or wd is not a valid watch descriptor.
// Watch descriptors are invalidated when they are removed explicitly or implicitly;
// explicitly by inotify_rm_watch, implicitly when the file they are watching is deleted.
return errno
}
return nil
}
type watch struct {
wd uint32 // Watch descriptor (as returned by the inotify_add_watch() syscall)
flags uint32 // inotify flags of this watch (see inotify(7) for the list of valid flags)
}
// readEvents reads from the inotify file descriptor, converts the
// received events into Event objects and sends them via the Events channel
func (w *Watcher) readEvents() {
var (
buf [unix.SizeofInotifyEvent * 4096]byte // Buffer for a maximum of 4096 raw events
n int // Number of bytes read with read()
errno error // Syscall errno
ok bool // For poller.wait
)
defer close(w.doneResp)
defer close(w.Errors)
defer close(w.Events)
defer unix.Close(w.fd)
defer w.poller.close()
for {
// See if we have been closed.
if w.isClosed() {
return
}
ok, errno = w.poller.wait()
if errno != nil {
select {
case w.Errors <- errno:
case <-w.done:
return
}
continue
}
if !ok {
continue
}
n, errno = unix.Read(w.fd, buf[:])
// If a signal interrupted execution, see if we've been asked to close, and try again.
// http://man7.org/linux/man-pages/man7/signal.7.html :
// "Before Linux 3.8, reads from an inotify(7) file descriptor were not restartable"
if errno == unix.EINTR {
continue
}
// unix.Read might have been woken up by Close. If so, we're done.
if w.isClosed() {
return
}
if n < unix.SizeofInotifyEvent {
var err error
if n == 0 {
// If EOF is received. This should really never happen.
err = io.EOF
} else if n < 0 {
// If an error occurred while reading.
err = errno
} else {
// Read was too short.
err = errors.New("notify: short read in readEvents()")
}
select {
case w.Errors <- err:
case <-w.done:
return
}
continue
}
var offset uint32
// We don't know how many events we just read into the buffer
// While the offset points to at least one whole event...
for offset <= uint32(n-unix.SizeofInotifyEvent) {
// Point "raw" to the event in the buffer
raw := (*unix.InotifyEvent)(unsafe.Pointer(&buf[offset]))
mask := uint32(raw.Mask)
nameLen := uint32(raw.Len)
if mask&unix.IN_Q_OVERFLOW != 0 {
select {
case w.Errors <- ErrEventOverflow:
case <-w.done:
return
}
}
// If the event happened to the watched directory or the watched file, the kernel
// doesn't append the filename to the event, but we would like to always fill the
// the "Name" field with a valid filename. We retrieve the path of the watch from
// the "paths" map.
w.mu.Lock()
name, ok := w.paths[int(raw.Wd)]
// IN_DELETE_SELF occurs when the file/directory being watched is removed.
// This is a sign to clean up the maps, otherwise we are no longer in sync
// with the inotify kernel state which has already deleted the watch
// automatically.
if ok && mask&unix.IN_DELETE_SELF == unix.IN_DELETE_SELF {
delete(w.paths, int(raw.Wd))
delete(w.watches, name)
}
w.mu.Unlock()
if nameLen > 0 {
// Point "bytes" at the first byte of the filename
bytes := (*[unix.PathMax]byte)(unsafe.Pointer(&buf[offset+unix.SizeofInotifyEvent]))
// The filename is padded with NULL bytes. TrimRight() gets rid of those.
name += "/" + strings.TrimRight(string(bytes[0:nameLen]), "\000")
}
event := newEvent(name, mask)
// Send the events that are not ignored on the events channel
if !event.ignoreLinux(mask) {
select {