fix issues cloudfoundry-incubator#371

jobs/kubelet/spec

@@ -14,6 +14,8 @@ templates:
   config/kubeletconfig.yml.erb: config/kubeletconfig.yml
   config/openstack-ca.crt.erb: config/openstack-ca.crt
   config/service_key.json.erb: config/service_key.json
+  monit.erb: monit
+
 packages:
 - pid_utils
 - kubernetes
@@ -24,6 +26,10 @@ properties:
     description: The token to access Kubernetes API
   cloud-provider:
     description: "The type of cloud-provider that is being deployed"
+  container-runtime:
+    description: "The container runtime job can be containerd or docker"
+    default: docker
+
   drain-api-token:
     description: The token to access Kubernetes API used to drain the kubelet.
   http_proxy:
@@ -54,6 +60,7 @@ properties:
   kubelet-drain-force-node:
     description: "Forcibly terminate pods if all the pods fail to drain before the timeout."
     default: false
+
   k8s-args:
     description: "Pass-through options for Kubernetes runtime arguments. See docs https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/ for reference."
     example: |

jobs/kubelet/templates/bin/kubelet_ctl.erb

@@ -3,6 +3,7 @@
 NAME="${0##*/}"
 
 export PATH=/var/vcap/packages/kubernetes/bin/:/var/vcap/packages/docker/sbin/:/var/vcap/packages/socat/bin/:$PATH
+export PATH=$PATH:/var/vcap/packages/containerd/bin
 
 RUN_DIR=/var/vcap/sys/run/kubernetes
 PIDFILE=$RUN_DIR/kubelet.pid

jobs/kubelet/templates/bin/post-start.erb

@@ -5,14 +5,24 @@
 
 kubectl="/var/vcap/packages/kubernetes/bin/kubectl --kubeconfig=/var/vcap/jobs/kubelet/config/kubeconfig"
 
-DOCKER_SOCKET=unix:///var/vcap/sys/run/docker/docker.sock
+
+if p('container-runtime').downcase == "docker"
+   DOCKER_SOCKET=unix:///var/vcap/sys/run/docker/docker.sock
+else if p('container-runtime').downcase == "containerd"
+   DOCKER_SOCKET=unix:///var/vcap/sys/run/containerd/containerd.sock
+end
+
 CONTAINER_IMAGE_DIR=/var/vcap/packages/kubernetes/container-images
 
 load_container() {
     path=$1
 
     echo "loading cached container: ${path}"
-    if sudo /var/vcap/jobs/kubelet/packages/docker/bin/docker -H ${DOCKER_SOCKET} load < "${path}"; then
+    if p('container-runtime').downcase == "containerd"
+    result = sudo ctr -n=k8s.io --address=/var/vcap/sys/run/containerd/containerd.sock images import "${path};
+    if p('container-runtime').downcase == "docker"
+    result = sudo /var/vcap/jobs/kubelet/packages/docker/bin/docker -H ${DOCKER_SOCKET} load < "${path}";
+    if $result then
       echo "successfully loaded container: ${path}"
     else
       echo "failed to load container: ${path}"

jobs/kubelet/templates/monit.erb

@@ -0,0 +1,12 @@
+check process kubelet
+  with pidfile /var/vcap/sys/run/kubernetes/kubelet.pid
+  start program "/var/vcap/jobs/kubelet/bin/kubelet_ctl start"
+  stop program "/var/vcap/jobs/kubelet/bin/kubelet_ctl stop"
+  group vcap
+  <%= if p("container-runtime").eq? "docker"
+  depends on docker
+  %>
+  <%= if p("container-runtime").eq? "containerd"
+  depends on containerd
+  %>
+