Merge pull request #346 from galal-hussein/external_etcd

External etcd

README.md

@@ -222,6 +222,32 @@ ingress:
 
 RKE will deploy Nginx Ingress controller as a DaemonSet with `hostnetwork: true`, so ports `80`, and `443` will be opened on each node where the controller is deployed.
 
+## External etcd
+
+RKE supports using external etcd instead of deploying etcd servers, to enable external etcd the following parameters should be populated:
+
+```
+services:
+  etcd:
+    path: /etcdcluster
+    external_urls:
+      - https://etcd-example.com:2379
+    ca_cert: |-
+      -----BEGIN CERTIFICATE-----
+      xxxxxxxxxx
+      -----END CERTIFICATE-----
+    cert: |-
+      -----BEGIN CERTIFICATE-----
+      xxxxxxxxxx
+      -----END CERTIFICATE-----
+    key: |-
+      -----BEGIN PRIVATE KEY-----
+      xxxxxxxxxx
+      -----END PRIVATE KEY-----
+```
+
+Note that RKE only supports connecting to TLS enabled etcd setup, user can enable multiple endpoints in the `external_urls` field. RKE will not accept having external urls and nodes with `etcd` role at the same time, user should only specify either etcd role for servers or external etcd but not both.
+
 ## Operating Systems Notes
 
 ### Atomic OS