fix(networking): allow cluster internal communication

since Scaleway does not have private DNS that resolves by default we have to
change the hostnames to the internal IP prior to registering workers.

Then the internal communication works fine

main.tf

@@ -42,6 +42,7 @@ resource "scaleway_server" "k8s-master" {
 
   provisioner "remote-exec" {
     inline = [
+      "sudo echo ${self.private_ip} > /tmp/private_ip",
       "sudo chmod +x /tmp/master.sh",
       "sudo /tmp/master.sh",
     ]
@@ -80,6 +81,7 @@ resource "scaleway_server" "k8s-worker" {
 
   provisioner "remote-exec" {
     inline = [
+      "sudo echo ${self.private_ip} > /tmp/private_ip",
       "sudo chmod +x /tmp/worker.sh",
       "sudo /tmp/worker.sh",
     ]

templates/master.sh

@@ -1,5 +1,12 @@
 #!/bin/bash -v
 
+# modify hostname to allow communication between Scaleway instances.
+private_ip=$(cat /tmp/private_ip)
+hostname $private_ip
+echo $private_ip > /etc/hostname
+echo "127.0.0.1 $private_ip" >> /etc/hosts
+
+# install kubernetes master
 apt-get install -y apt-transport-https
 
 curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
@@ -11,7 +18,7 @@ apt-get install -y kubelet kubeadm kubectl kubernetes-cni
 curl -sSL https://get.docker.com/ | sh
 systemctl start docker
 
-kubeadm init --token=${k8stoken}
+kubeadm init --token=${k8stoken} --use-kubernetes-version v1.4.3
 
 kubectl apply -f https://git.io/weave-kube
 

templates/worker.sh

@@ -1,5 +1,12 @@
 #!/bin/bash -v
 
+# modify hostname to allow communication between Scaleway instances.
+private_ip=$(cat /tmp/private_ip)
+hostname $private_ip
+echo $private_ip > /etc/hostname
+echo "127.0.0.1 $private_ip" >> /etc/hosts
+
+# install kubernetes worker
 apt-get install -y apt-transport-https
 
 curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -