GCE: Allow for reuse of master

This is for internal use at the moment, for testing Ubernetes Lite, but
arguably makes the code a little cleaner.

Also rename KUBE_SHARE_MASTER -> KUBE_USE_EXISTING_MASTER

cluster/aws/util.sh

@@ -20,7 +20,7 @@
 # The intent is to allow experimentation/advanced functionality before we
 # are ready to commit to supporting it.
 # Experimental functionality:
-#   KUBE_SHARE_MASTER=true
+#   KUBE_USE_EXISTING_MASTER=true
 #     Detect and reuse an existing master; useful if you want to
 #     create more nodes, perhaps with a different instance type or in
 #     a different subnet/AZ
@@ -808,8 +808,8 @@ function kube-up {
   # HTTPS to the master is allowed (for API access)
   authorize-security-group-ingress "${MASTER_SG_ID}" "--protocol tcp --port 443 --cidr 0.0.0.0/0"
 
-  # KUBE_SHARE_MASTER is used to add minions to an existing master
+  # KUBE_USE_EXISTING_MASTER is used to add minions to an existing master
-  if [[ "${KUBE_SHARE_MASTER:-}" == "true" ]]; then
+  if [[ "${KUBE_USE_EXISTING_MASTER:-}" == "true" ]]; then
     # Detect existing master
     detect-master
 

cluster/gce/util.sh

@@ -575,6 +575,22 @@ function kube-up {
   find-release-tars
   upload-server-tars
 
+  if [[ ${KUBE_USE_EXISTING_MASTER:-} == "true" ]]; then
+    create-nodes
+    create-autoscaler
+  else
+    check-existing
+    create-network
+    create-master
+    create-nodes-firewall
+    create-nodes-template
+    create-nodes
+    create-autoscaler
+    check-cluster
+  fi
+}
+
+function check-existing() {
   local running_in_terminal=false
   # May be false if tty is not allocated (for example with ssh -T).
   if [ -t 1 ]; then
@@ -595,7 +611,9 @@ function kube-up {
       fi
     fi
   fi
+}
 
+function create-network() {
   if ! gcloud compute networks --project "${PROJECT}" describe "${NETWORK}" &>/dev/null; then
     echo "Creating new network: ${NETWORK}"
     # The network needs to be created synchronously or we have a race. The
@@ -618,7 +636,9 @@ function kube-up {
       --source-ranges "0.0.0.0/0" \
       --allow "tcp:22" &
   fi
+}
 
+function create-master() {
   echo "Starting master and configuring firewalls"
   gcloud compute firewall-rules create "${MASTER_NAME}-https" \
     --project "${PROJECT}" \
@@ -663,7 +683,9 @@ function kube-up {
   create-certs "${MASTER_RESERVED_IP}"
 
   create-master-instance "${MASTER_RESERVED_IP}" &
+}
 
+function create-nodes-firewall() {
   # Create a single firewall rule for all minions.
   create-firewall-rule "${NODE_TAG}-all" "${CLUSTER_IP_RANGE}" "${NODE_TAG}" &
 
@@ -676,7 +698,9 @@ function kube-up {
   kube::util::wait-for-jobs || {
     echo -e "${color_red}${fail} commands failed.${color_norm}" >&2
   }
+}
 
+function create-nodes-template() {
   echo "Creating minions."
 
   # TODO(zmerlynn): Refactor setting scope flags.
@@ -690,8 +714,12 @@ function kube-up {
   write-node-env
 
   local template_name="${NODE_INSTANCE_PREFIX}-template"
-  
+
   create-node-instance-template $template_name
+}
+
+function create-nodes() {
+  local template_name="${NODE_INSTANCE_PREFIX}-template"
 
   local defaulted_max_instances_per_mig=${MAX_INSTANCES_PER_MIG:-500}
 
@@ -731,10 +759,9 @@ function kube-up {
       "${NODE_INSTANCE_PREFIX}-group" \
       --zone "${ZONE}" \
       --project "${PROJECT}" || true;
+}
 
-  detect-node-names
+function create-autoscaler() {
-  detect-master
-
   # Create autoscaler for nodes if requested
   if [[ "${ENABLE_NODE_AUTOSCALER}" == "true" ]]; then
     METRICS=""
@@ -764,6 +791,11 @@ function kube-up {
     gcloud compute instance-groups managed set-autoscaling "${NODE_INSTANCE_PREFIX}-group" --zone "${ZONE}" --project "${PROJECT}" \
       --min-num-replicas "${last_min_instances}" --max-num-replicas "${last_max_instances}" ${METRICS} || true
   fi
+}
+
+function check-cluster() {
+  detect-node-names
+  detect-master
 
   echo "Waiting up to ${KUBE_CLUSTER_INITIALIZATION_TIMEOUT} seconds for cluster initialization."
   echo
@@ -845,7 +877,7 @@ function kube-down {
   fi
 
   # Get the name of the managed instance group template before we delete the
-  # managed instange group. (The name of the managed instnace group template may
+  # managed instance group. (The name of the managed instance group template may
   # change during a cluster upgrade.)
   local template=$(get-template "${PROJECT}" "${ZONE}" "${NODE_INSTANCE_PREFIX}-group")
 

docs/proposals/federation-lite.md

@@ -71,7 +71,7 @@ make multiple zones better supported.
 For the initial implemenation, kube-up must be run multiple times, once for
 each zone.  The first kube-up will take place as normal, but then for each
 additional zone the user must run kube-up again, specifying
-`KUBE_SHARE_MASTER=true` and `KUBE_SUBNET_CIDR=172.20.x.0/24`.  This will then
+`KUBE_USE_EXISTING_MASTER=true` and `KUBE_SUBNET_CIDR=172.20.x.0/24`.  This will then
 create additional nodes in a different zone, but will register them with the
 existing master.