Auto-calculate CLUSTER_IP_RANGE based on no. of nodes

cluster/gce/config-common.sh

@@ -84,6 +84,20 @@ function get-node-ip-range {
   echo "${suggested_range}"
 }
 
+function get-cluster-ip-range {
+  local suggested_range="10.100.0.0/14"
+  if [[ "${NUM_NODES}" -gt 1000 ]]; then
+    suggested_range="10.100.0.0/13"
+  fi
+  if [[ "${NUM_NODES}" -gt 2000 ]]; then
+    suggested_range="10.100.0.0/12"
+  fi
+  if [[ "${NUM_NODES}" -gt 4000 ]]; then
+    suggested_range="10.100.0.0/11"
+  fi
+  echo "${suggested_range}" 
+}
+
 if [[ "${FEDERATION:-}" == true ]]; then
     NODE_SCOPES="${NODE_SCOPES:-compute-rw,monitoring,logging-write,storage-ro,https://www.googleapis.com/auth/ndev.clouddns.readwrite}"
 else

cluster/gce/config-default.sh

@@ -92,7 +92,7 @@ ETCD_QUORUM_READ="${ENABLE_ETCD_QUORUM_READ:-false}"
 MASTER_TAG="${INSTANCE_PREFIX}-master"
 NODE_TAG="${INSTANCE_PREFIX}-minion"
 
-CLUSTER_IP_RANGE="${CLUSTER_IP_RANGE:-10.244.0.0/14}"
+CLUSTER_IP_RANGE="${CLUSTER_IP_RANGE:-$(get-cluster-ip-range)}"
 MASTER_IP_RANGE="${MASTER_IP_RANGE:-10.246.0.0/24}"
 
 if [[ "${FEDERATION:-}" == true ]]; then

cluster/gce/config-test.sh

@@ -93,7 +93,7 @@ ETCD_QUORUM_READ="${ENABLE_ETCD_QUORUM_READ:-false}"
 MASTER_TAG="${INSTANCE_PREFIX}-master"
 NODE_TAG="${INSTANCE_PREFIX}-minion"
 
-CLUSTER_IP_RANGE="${CLUSTER_IP_RANGE:-10.100.0.0/14}"
+CLUSTER_IP_RANGE="${CLUSTER_IP_RANGE:-$(get-cluster-ip-range)}"
 MASTER_IP_RANGE="${MASTER_IP_RANGE:-10.246.0.0/24}"
 # NODE_IP_RANGE is used when ENABLE_IP_ALIASES=true. It is the primary range in
 # the subnet and is the range used for node instance IPs.

test/e2e/framework/test_context.go

@@ -301,4 +301,8 @@ func AfterReadingAllFlags(t *TestContextType) {
 	if len(t.Host) == 0 && len(t.KubeConfig) == 0 {
 		t.Host = defaultHost
 	}
+	// Reset the cluster IP range flag to CLUSTER_IP_RANGE env var, if defined.
+	if clusterIPRange := os.Getenv("CLUSTER_IP_RANGE"); clusterIPRange != "" {
+		t.CloudConfig.ClusterIPRange = clusterIPRange
+	}
 }