kubernetes: Use pkg/metadata

Still a flat/unstructured config space, but at least uses the mounting
machinery.

`boot.sh` continues to just work without modification.

Signed-off-by: Ian Campbell <ijc@docker.com>

projects/kubernetes/kube-master.yml

@@ -13,6 +13,8 @@ onboot:
     image: linuxkit/sysfs:006a65b30cfdd9d751d7ab042fde7eca2c3bc9dc
   - name: binfmt
     image: linuxkit/binfmt:0bde4ebd422099f45c5ee03217413523ad2223e5
+  - name: metadata
+    image: linuxkit/metadata:f122f1b4e873f1d08cd67bd9105385fd923af0cb
   - name: format
     image: linuxkit/format:84a997e69051a1bf05b7c1926ab785bb07932954
   - name: mounts

projects/kubernetes/kube-node.yml

@@ -13,6 +13,8 @@ onboot:
     image: linuxkit/sysfs:006a65b30cfdd9d751d7ab042fde7eca2c3bc9dc
   - name: binfmt
     image: linuxkit/binfmt:0bde4ebd422099f45c5ee03217413523ad2223e5
+  - name: metadata
+    image: linuxkit/metadata:f122f1b4e873f1d08cd67bd9105385fd923af0cb
   - name: format
     image: linuxkit/format:84a997e69051a1bf05b7c1926ab785bb07932954
   - name: mounts

projects/kubernetes/kubernetes/kubelet.sh

@@ -12,9 +12,9 @@ until kubelet --kubeconfig=/var/lib/kubeadm/kubelet.conf \
 	      --network-plugin=cni \
 	      --cni-conf-dir=/etc/cni/net.d \
 	      --cni-bin-dir=/opt/cni/bin ; do
-    if [ ! -e /dev/sr0 ] ; then
+    if [ ! -f /var/config/userdata ] ; then
 	sleep 1
     else
-	mount -o ro /dev/sr0 /mnt && kubeadm join --skip-preflight-checks $(cat /mnt/config)
+	kubeadm join --skip-preflight-checks $(cat /var/config/userdata)
     fi
 done