Merge pull request #34 from thaJeztah/18.06-backport-logissue
[18.06] backport select polling based watcher for Windows log watcher
diff --git a/daemon/logger/loggerutils/logfile.go b/daemon/logger/loggerutils/logfile.go
index 6e3cda8..96575e3 100644
--- a/daemon/logger/loggerutils/logfile.go
+++ b/daemon/logger/loggerutils/logfile.go
@@ -8,6 +8,7 @@
"fmt"
"io"
"os"
+ "runtime"
"strconv"
"strings"
"sync"
@@ -641,9 +642,20 @@
}
func watchFile(name string) (filenotify.FileWatcher, error) {
- fileWatcher, err := filenotify.New()
- if err != nil {
- return nil, err
+ var fileWatcher filenotify.FileWatcher
+
+ if runtime.GOOS == "windows" {
+ // FileWatcher on Windows files is based on the syscall notifications which has an issue becuase of file caching.
+ // It is based on ReadDirectoryChangesW() which doesn't detect writes to the cache. It detects writes to disk only.
+ // Becuase of the OS lazy writing, we don't get notifications for file writes and thereby the watcher
+ // doesn't work. Hence for Windows we will use poll based notifier.
+ fileWatcher = filenotify.NewPollingWatcher()
+ } else {
+ var err error
+ fileWatcher, err = filenotify.New()
+ if err != nil {
+ return nil, err
+ }
}
logger := logrus.WithFields(logrus.Fields{
@@ -652,6 +664,7 @@
})
if err := fileWatcher.Add(name); err != nil {
+ // we will retry using file poller.
logger.WithError(err).Warnf("falling back to file poller")
fileWatcher.Close()
fileWatcher = filenotify.NewPollingWatcher()
@@ -662,5 +675,6 @@
return nil, err
}
}
+
return fileWatcher, nil
}
