From 3808519907b23cd1d67c3afa220c0c6774f048be Mon Sep 17 00:00:00 2001
From: Jerzy Szczepkowski <jsz@google.com>
Date: Wed, 8 Jul 2015 16:48:33 +0200
Subject: [PATCH] Optional creation of nodes autoscaler for GCE.

Implemented optional creation and deletion of nodes autoscaler in kube-up and kube-down scripts for GCE.
---
 cluster/gce/config-default.sh |  9 +++++++++
 cluster/gce/config-test.sh    |  9 +++++++++
 cluster/gce/util.sh           | 21 +++++++++++++++++++++
 3 files changed, 39 insertions(+)

diff --git a/cluster/gce/config-default.sh b/cluster/gce/config-default.sh
index c6f31c93a5..98e9aee6e8 100755
--- a/cluster/gce/config-default.sh
+++ b/cluster/gce/config-default.sh
@@ -74,6 +74,15 @@ DNS_SERVER_IP="10.0.0.10"
 DNS_DOMAIN="cluster.local"
 DNS_REPLICAS=1
 
+# Optional: Create autoscaler for cluster's nodes.
+# NOT WORKING YET!
+ENABLE_NODE_AUTOSCALER="${KUBE_ENABLE_NODE_AUTOSCALER:-false}"
+if [[ "${ENABLE_NODE_AUTOSCALER}" == "true" ]]; then
+  AUTOSCALER_MIN_NODES="${KUBE_AUTOSCALER_MIN_NODES:-1}"
+  AUTOSCALER_MAX_NODES="${KUBE_AUTOSCALER_MAX_NODES:-${NUM_MINIONS}}"
+  TARGET_NODE_UTILIZATION="${KUBE_TARGET_NODE_UTILIZATION:-0.7}"
+fi
+
 # Admission Controllers to invoke prior to persisting objects in cluster
 ADMISSION_CONTROL=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota
 
diff --git a/cluster/gce/config-test.sh b/cluster/gce/config-test.sh
index fae9b7fa63..04d96cadc5 100755
--- a/cluster/gce/config-test.sh
+++ b/cluster/gce/config-test.sh
@@ -72,6 +72,15 @@ DNS_SERVER_IP="10.0.0.10"
 DNS_DOMAIN="cluster.local"
 DNS_REPLICAS=1
 
+# Optional: Create autoscaler for cluster's nodes.
+# NOT WORKING YET!
+ENABLE_NODE_AUTOSCALER="${KUBE_ENABLE_NODE_AUTOSCALER:-false}"
+if [[ "${ENABLE_NODE_AUTOSCALER}" == "true" ]]; then
+  AUTOSCALER_MIN_NODES="${KUBE_AUTOSCALER_MIN_NODES:-1}"
+  AUTOSCALER_MAX_NODES="${KUBE_AUTOSCALER_MAX_NODES:-${NUM_MINIONS}}"
+  TARGET_NODE_UTILIZATION="${KUBE_TARGET_NODE_UTILIZATION:-0.7}"
+fi
+
 ADMISSION_CONTROL=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota
 
 # Optional: if set to true kube-up will automatically check for existing resources and clean them up.
diff --git a/cluster/gce/util.sh b/cluster/gce/util.sh
index af355ca3d8..5570497b1b 100755
--- a/cluster/gce/util.sh
+++ b/cluster/gce/util.sh
@@ -708,6 +708,18 @@ function kube-up {
   detect-minion-names
   detect-master
 
+  # Create autoscaler for nodes if requested
+  if [[ "${ENABLE_NODE_AUTOSCALER}" == "true" ]]; then
+    METRICS=""
+    METRICS+="--custom-metric-utilization metric=custom.cloudmonitoring.googleapis.com/kubernetes.io/cpu/node_utilization,"
+    METRICS+="utilization-target=${TARGET_NODE_UTILIZATION},utilization-target-type=GAUGE "
+    METRICS+="--custom-metric-utilization metric=custom.cloudmonitoring.googleapis.com/kubernetes.io/memory/node_utilization,"
+    METRICS+="utilization-target=${TARGET_NODE_UTILIZATION},utilization-target-type=GAUGE "
+    echo "Creating node autoscaler."
+    gcloud preview autoscaler --zone "${ZONE}" create "${NODE_INSTANCE_PREFIX}-autoscaler" --target "${NODE_INSTANCE_PREFIX}-group" \
+        --min-num-replicas "${AUTOSCALER_MIN_NODES}" --max-num-replicas "${AUTOSCALER_MAX_NODES}" ${METRICS} || true
+  fi
+
   echo "Waiting for cluster initialization."
   echo
   echo "  This will continually check to see if the API for kubernetes is reachable."
@@ -769,6 +781,15 @@ function kube-down {
   echo "Bringing down cluster"
   set +e  # Do not stop on error
 
+  # Delete autoscaler for nodes if present.
+  local autoscaler
+  autoscaler=( $(gcloud preview autoscaler --zone "${ZONE}" list \
+                 | awk 'NR >= 2 { print $1 }' \
+                 | grep "${NODE_INSTANCE_PREFIX}-autoscaler") )
+  if [[ "${autoscaler:-}" != "" ]]; then
+    gcloud preview autoscaler --zone "${ZONE}" delete "${NODE_INSTANCE_PREFIX}-autoscaler"
+  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
   # change during a cluster upgrade.)