func ExampleNewWatcher() {
watcher, err := fsnotify.NewWatcher()
if err != nil {
log.Fatal(err)
}
go func() {
for {
select {
case ev := <-watcher.Event:
log.Println("event:", ev)
case err := <-watcher.Error:
log.Println("error:", err)
}
}
}()
err = watcher.Watch("/tmp/foo")
if err != nil {
log.Fatal(err)
}
}
// RolesWatch catches filesystem notify events to determine when new roles files are ready to be read
// in and used as new authentication values.
func (rf *RolesFiles) RolesWatch(err_chan chan error, read_signal chan bool) {
log.Printf("initiate roles watching\n")
watcher, watcher_err := fsnotify.NewWatcher()
if watcher_err != nil {
err_chan <- watcher_err
}
watch_err := watcher.Watch(rf.BaseDir)
if watch_err != nil {
err_chan <- watch_err
}
defer watcher.Close()
touched_access_file := false
touched_secret_file := false
touched_token_file := false
func() {
for {
select {
case ev := <-watcher.Event:
func() {
if ev.IsModify() || ev.IsCreate() {
ev_s := ev.String()
// collect events for all of the role files.
// we only want to read in and reset the
// strings when all have been written - to
// do so earlier would leave the strings
// in an inconsistent state
if strings.Contains(ev_s, rf.AccessKeyFile) {
touched_access_file = true
}
if strings.Contains(ev_s, rf.SecretFile) {
touched_secret_file = true
}
if strings.Contains(ev_s, rf.TokenFile) {
touched_token_file = true
}
// once we have seen all of the role files trigger
// events, we want to lock access, read them in,
// unlock access, and unset our flags
if touched_access_file &&
touched_secret_file &&
touched_token_file {
// our existing perms should be adequate while
// we provide for writes of new perms files to
// finish.
log.Printf("roles_files.RolesWatch: " +
"sleep (1) to allow file ops to complete")
time.Sleep(time.Duration(1) * time.Second)
roles_err := rf.rolesFilesRead()
if roles_err != nil {
e := fmt.Sprintf("roles_files.RolesWatch: "+
"zeroing all roles on err:%s",
roles_err.Error())
log.Printf(e)
rf.ZeroRoles()
err_chan <- roles_err
} else {
log.Printf("roles_files.RolesWatch: "+
"succesful re-read on %s\n",
ev_s)
touched_access_file = false
touched_secret_file = false
touched_token_file = false
read_signal <- true
}
}
}
}()
case err := <-watcher.Error:
// return an error to the caller via the channel
err_chan <- err
}
}
}()
// typically not reached, but signifies normal termination
log.Printf("terminating roles watching\n")
err_chan <- nil
}