Update Readme.md

Author: Random-Liu

README.md

@@ -97,11 +97,17 @@ spec:
         - name: log
           mountPath: /log
           readOnly: true
+        - name: localtime
+          mountPath: /etc/localtime
+          readOnly: true
       volumes:
       - name: log
         # Config `log` to your system log directory
         hostPath:
           path: /var/log/
+      - name: localtime
+        hostPath:
+          path: /etc/localtime
 ```
 * Edit node-problem-detector.yaml to fit your environment: Set `log` volume to your system log diretory. (Used by KernelMonitor)
 * Create the DaemonSet with `kubectl create -f node-problem-detector.yaml`

config/kernel-monitor.json

@@ -1,6 +1,6 @@
 {
 	"plugin": "journald",
-	"logPath": "/log/journal",
+	"logPath": "/var/log/journal",
 	"lookback": "10m",
 	"startPattern": "Initializing cgroup subsys cpuset",
 	"bufferSize": 10,

node-problem-detector.yaml

@@ -25,7 +25,7 @@ spec:
               fieldPath: spec.nodeName
         volumeMounts:
         - name: log
-          mountPath: /log
+          mountPath: /var/log
           readOnly: true
         # Make sure node problem detector is in the same timezone
         # with the host.

pkg/kernelmonitor/README.md

@@ -9,12 +9,8 @@ The rule list is extensible.
 
 ## Limitations
 
-* Kernel Monitor only supports file based kernel log now. It doesn't support log tools
-like journald. There is an [open issue](https://github.com/kubernetes/node-problem-detector/issues/14)
-to add journald support.
-
-* Kernel Monitor has assumption on kernel log format, now it only works on Ubuntu and
-Debian. However, it is easy to extend it to [support other log format](#support-other-log-format).
+* Kernel Monitor only supports syslog (rsyslog) and journald now, but it is easy
+  to extend it with [new log watcher](#new-log-watcher)
 
 ## Add New NodeConditions
 
@@ -43,14 +39,23 @@ with new rule definition:
 }
 ```
 
-## Change Log Path
+## Log Watchers
+
+Kernel monitor supports different log management tools with different log
+watchers:
+* [syslog](https://github.com/kubernetes/node-problem-detector/blob/master/pkg/kernelmonitor/logwatchers/syslog)
+* [journald](https://github.com/kubernetes/node-problem-detector/blob/master/pkg/kernelmonitor/logwatchers/journald)
+
+### Change Log Path
 
-Kernel log in different OS distros may locate in different path. The `log`
+Kernel log on different OS distros may locate in different path. The `logPath`
 field in `config/kernel-monitor.json` is the log path inside the container.
-You can always configure it to match your OS distro.
+You can always configure `logPath` and volume mount to match your OS distro.
+* syslog: `logPath` is the kernel log path, usually `/var/log/kern.log`.
+* journald: `logPath` is the journal log directory, usually `/var/log/journal`.
 
-## Support Other Log Format
+### New Log Watcher
 
-Kernel monitor uses [`Translator`](https://github.com/kubernetes/node-problem-detector/blob/master/pkg/kernelmonitor/translator/translator.go)
-plugin to translate kernel log the internal data structure. It is easy to
-implement a new translator for a new log format.
+Kernel monitor uses [Log
+Watcher](https://github.com/kubernetes/node-problem-detector/blob/master/pkg/kernelmonitor/logwatchers/types/log_watcher.go) to support different log management tools.
+It is easy to implement a new log watcher.