plugin/kubernetes: Disable resync by default (#2752)

* Disable resync by default

* Document default resync

plugin/kubernetes/README.md

@@ -48,7 +48,8 @@ kubernetes [ZONES...] {
 }
 ```
 
-* `resyncperiod` specifies the Kubernetes data API **DURATION** period.
+* `resyncperiod` specifies the Kubernetes data API **DURATION** period. By
+  default resync is disabled (DURATION is zero).
 * `endpoint` specifies the **URL** for a remote k8s API endpoint.
    If omitted, it will connect to k8s in-cluster using the cluster service account.
 * `tls` **CERT** **KEY** **CACERT** are the TLS cert, key and the CA cert file names for remote k8s connection.

plugin/kubernetes/setup.go

@@ -321,4 +321,4 @@ func searchFromResolvConf() []string {
 	return rc.Search
 }
 
-const defaultResyncPeriod = 5 * time.Hour
+const defaultResyncPeriod = 0