add documnetatin to enable debug logging

site/kubernetes/kube-addon.md

@@ -198,6 +198,18 @@ $ kubectl logs -n kube-system weave-net-1jkl6 weave
 For easier viewing, pipe the output into a file , especially if
 it is long.
 
+By default log level is set to `info`. If you wish to see more detailed logs you can set the desired log level for the `-log-level` flag through the `EXTRA_ARGS` environment variable for the `weave` and `weave-npc` containers in the weave-net daemon set. Add environment variable as below.
+
+```yaml
+      containers:
+      - command:
+        - /home/weave/launch.sh
+        name: weave
+        env:
+        - name: EXTRA_ARGS
+          value: --log-level=debug
+```
+
 Many Kubernetes network issues occur at a higher level than Weave Net.
 The [Kubernetes Service Debugging Guide]
 (https://kubernetes.io/docs/tasks/debug-application-cluster/debug-service/)