Add node_labels variable in workers modules to set initial node labels (#550)

* Also add `worker_node_labels` variable in `kubernetes` modules to set
initial node labels for the default workers

google-cloud/container-linux/kubernetes/workers/cl/worker.yaml.tmpl

@@ -60,6 +60,9 @@ systemd:
           --lock-file=/var/run/lock/kubelet.lock \
           --network-plugin=cni \
           --node-labels=node.kubernetes.io/node \
+          %{ for label in split(",", node_labels) }
+          --node-labels=${label} \
+          %{ endfor ~}
           --pod-manifest-path=/etc/kubernetes/manifests \
           --read-only-port=0 \
           --volume-plugin-dir=/var/lib/kubelet/volumeplugins

google-cloud/container-linux/kubernetes/workers/variables.tf

@@ -81,6 +81,12 @@ variable "cluster_domain_suffix" {
   default = "cluster.local"
 }
 
+variable "node_labels" {
+  description = "List of additional labels to add to worker nodes"
+  type = list
+  default = []
+}
+
 variable "clc_snippets" {
   type = list(string)
   description = "Container Linux Config snippets"

google-cloud/container-linux/kubernetes/workers/workers.tf

@@ -82,6 +82,7 @@ data "template_file" "worker-config" {
     ssh_authorized_key     = var.ssh_authorized_key
     cluster_dns_service_ip = cidrhost(var.service_cidr, 10)
     cluster_domain_suffix  = var.cluster_domain_suffix
+    node_labels            = join(",", var.node_labels)
   }
 }