update docs

Author: splichy

autogen/main/README.md

@@ -218,7 +218,7 @@ The node_pools variable takes the following parameters:
 | name | The name of the node pool |  | Required |
 {% if beta_cluster %}
 | placement_policy | Placement type to set for nodes in a node pool. Can be set as [COMPACT](https://cloud.google.com/kubernetes-engine/docs/how-to/compact-placement#overview) if desired | Optional |
-| pod_range |  The ID of the secondary range for pod IPs. |  | Optional |
+| pod_range |  The name of the secondary range for pod IPs. |  | Optional |
 {% endif %}
 | node_count | The number of nodes in the nodepool when autoscaling is false. Otherwise defaults to 1. Only valid for non-autoscaling clusters |  | Required |
 | node_locations | The list of zones in which the cluster's nodes are located. Nodes must be in the region of their regional cluster or in the same region as their cluster's zone for zonal clusters. Defaults to cluster level node locations if nothing is specified | " " | Optional |

docs/private_clusters.md

@@ -20,6 +20,16 @@ If you are using these features with a private cluster, you will need to either:
 
 If you are going to isolate your GKE private clusters from internet access you could check [this guide](https://medium.com/google-cloud/completely-private-gke-clusters-with-no-internet-connectivity-945fffae1ccd) and the associated [repo](https://github.com/andreyk-code/no-inet-gke-cluster).
 
+## Discontiguous multi-Pod CIDR
+If you are going to use [discontiguous multi-Pod CIDR](https://cloud.google.com/kubernetes-engine/docs/how-to/multi-pod-cidr) it can happen that GKE robot will not update `gke-[cluster-name]-[cluster-hash]-all` and other firewall rules automatically when you add a new node pool (as stated in [documentation](https://cloud.google.com/kubernetes-engine/docs/how-to/multi-pod-cidr#modified_firewall_rule)). You can prevent this from happening, by using a workaround with shadow firewall rules:
+```
+module "gke" {
+  ...
+  add_shadow_firewall_rules  = true
+  shadow_firewall_rules_log_config = null # to save some $ on logs
+}
+``` 
+
 ## Troubleshooting
 
 ### Master Authorized Network