Merge pull request #2563 from ijc/kubernetes

kubernetes: easier support for single master, plus slight robustness improvement

projects/kubernetes/boot.sh

@@ -5,6 +5,7 @@ set -e
 : ${KUBE_MASTER_VCPUS:=2}
 : ${KUBE_MASTER_MEM:=1024}
 : ${KUBE_MASTER_DISK:=4G}
+: ${KUBE_MASTER_UNTAINT:=n}
 
 : ${KUBE_NODE_VCPUS:=2}
 : ${KUBE_NODE_MEM:=4096}
@@ -27,10 +28,16 @@ if [ $# -eq 0 ] ; then
     # then we configure for auto init. If it is completely unset then
     # we do not.
     if [ -n "${KUBE_MASTER_AUTOINIT+x}" ] ; then
-	data="{\"kubeadm\": {\"init\": \"${KUBE_MASTER_AUTOINIT}\"} }"
-    else
-	data=""
+	kubeadm_data="${kubeadm_data+$kubeadm_data, }\"init\": \"${KUBE_MASTER_AUTOINIT}\""
     fi
+    if [ "${KUBE_MASTER_UNTAINT}" = "y" ] ; then
+	kubeadm_data="${kubeadm_data+$kubeadm_data, }\"untaint-master\": \"\""
+    fi
+
+    if [ -n "${kubeadm_data}" ] ; then
+	data="{ \"kubeadm\": { ${kubeadm_data} } }"
+    fi
+
     state="kube-master-state"
 
     : ${KUBE_VCPUS:=$KUBE_MASTER_VCPUS}

projects/kubernetes/kube.yml

@@ -36,7 +36,7 @@ services:
   - name: sshd
     image: linuxkit/sshd:d313eea3d9d7fbcbc927d06a6700325725db2a82
   - name: kubelet
-    image: linuxkitprojects/kubernetes:98d03686d3665b935dcd68da192f79c4cb618ec7
+    image: linuxkitprojects/kubernetes:2a42ca12c52a756ffd83ec014f2b396891880e4a
 files:
   - path: etc/linuxkit.yml
     metadata: yaml

projects/kubernetes/kubernetes/kubeadm-init.sh

@@ -1,5 +1,6 @@
 #!/bin/sh
 set -e
+touch /var/lib/kubeadm/.kubeadm-init.sh-started
 kubeadm init --skip-preflight-checks --kubernetes-version @KUBERNETES_VERSION@ $@
 for i in /etc/kubeadm/kube-system.init/*.yaml ; do
     if [ -e "$i" ] ; then
@@ -7,3 +8,8 @@ for i in /etc/kubeadm/kube-system.init/*.yaml ; do
 	kubectl create -n kube-system -f "$i"
     fi
 done
+if [ -f /var/config/kubeadm/untaint-master ] ; then
+    echo "Removing \"node-role.kubernetes.io/master\" taint from all nodes"
+    kubectl taint nodes --all node-role.kubernetes.io/master-
+fi
+touch /var/lib/kubeadm/.kubeadm-init.sh-finished

projects/kubernetes/kubernetes/kubelet.sh

@@ -15,15 +15,17 @@ await=/etc/kubernetes/kubelet.conf
 
 if [ -f "/etc/kubernetes/kubelet.conf" ] ; then
     echo "kubelet.sh: kubelet already configured"
-elif [ -e /var/config/kubeadm/init ] ; then
-    echo "kubelet.sh: init cluster with metadata \"$(cat /var/config/kubeadm/init)\""
-    # This needs to be in the background since it waits for kubelet to start.
-    # We skip printing the token so it is not persisted in the log.
-    kubeadm-init.sh --skip-token-print $(cat /var/config/kubeadm/init) &
-elif [ -e /var/config/kubeadm/join ] ; then
-    echo "kubelet.sh: joining cluster with metadata \"$(cat /var/config/kubeadm/join)\""
-    kubeadm join --skip-preflight-checks $(cat /var/config/kubeadm/join)
-    await=/etc/kubernetes/bootstrap-kubelet.conf
+elif [ -d /var/config/kubeadm ] ; then
+    if [ -f /var/config/kubeadm/init ] ; then
+	echo "kubelet.sh: init cluster with metadata \"$(cat /var/config/kubeadm/init)\""
+	# This needs to be in the background since it waits for kubelet to start.
+	# We skip printing the token so it is not persisted in the log.
+	kubeadm-init.sh --skip-token-print $(cat /var/config/kubeadm/init) &
+    elif [ -e /var/config/kubeadm/join ] ; then
+	echo "kubelet.sh: joining cluster with metadata \"$(cat /var/config/kubeadm/join)\""
+	kubeadm join --skip-preflight-checks $(cat /var/config/kubeadm/join)
+	await=/etc/kubernetes/bootstrap-kubelet.conf
+    fi
 elif [ -e /var/config/userdata ] ; then
     echo "kubelet.sh: joining cluster with metadata \"$(cat /var/config/userdata)\""
     kubeadm join --skip-preflight-checks $(cat /var/config/userdata)