Systemd units, limits, and bin path fixes

* Add restart for weave service unit
* Reuse docker_bin_dir everythere
* Limit systemd managed docker containers by CPU/RAM. Do not configure native
  systemd limits due to the lack of consensus in the kernel community
  requires out-of-tree kernel patches.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

roles/kubernetes/node/defaults/main.yml

@@ -9,6 +9,18 @@ kube_proxy_mode: iptables
 # If using the pure iptables proxy, SNAT everything
 kube_proxy_masquerade_all: true
 
+# Limits for kube components and nginx load balancer app
+kubelet_memory_limit: 512M
+kubelet_cpu_limit: 100m
+kube_proxy_memory_limit: 2000M
+kube_proxy_cpu_limit: 500m
+kube_proxy_memory_requests: 256M
+kube_proxy_cpu_requests: 150m
+nginx_memory_limit: 512M
+nginx_cpu_limit: 300m
+nginx_memory_requests: 64M
+nginx_cpu_requests: 50m
+
 # kube_api_runtime_config:
 #   - extensions/v1beta1/daemonsets=true
 #   - extensions/v1beta1/deployments=true

roles/kubernetes/node/templates/deb-kubelet.initd.j2

@@ -39,7 +39,7 @@ DAEMON_USER=root
 #
 do_start()
 {
-        /usr/bin/docker rm -f kubelet &>/dev/null || true
+        {{ docker_bin_dir }}/docker rm -f kubelet &>/dev/null || true
         sleep 1
         # Return
         #   0 if daemon has been started

roles/kubernetes/node/templates/kubelet-container.j2

@@ -1,5 +1,5 @@
 #!/bin/bash
-/usr/bin/docker run --privileged \
+{{ docker_bin_dir }}/docker run --privileged \
 --net=host --pid=host --name=kubelet --restart=on-failure:5 \
 -v /etc/cni:/etc/cni:ro \
 -v /opt/cni:/opt/cni:ro \
@@ -9,6 +9,7 @@
 -v {{ docker_daemon_graph }}:/var/lib/docker \
 -v /var/run:/var/run \
 -v /var/lib/kubelet:/var/lib/kubelet \
+--memory={{ kubelet_memory_limit|regex_replace('Mi', 'M') }} --cpu-shares={{ kubelet_cpu_limit|regex_replace('m', '')  }} \
 {{ hyperkube_image_repo }}:{{ hyperkube_image_tag}} \
 nsenter --target=1 --mount --wd=. -- \
 ./hyperkube kubelet \

roles/kubernetes/node/templates/kubelet.service.j2

@@ -23,8 +23,8 @@ ExecStart={{ bin_dir }}/kubelet \
 		$DOCKER_SOCKET \
 		$KUBELET_NETWORK_PLUGIN \
 		$KUBELET_CLOUDPROVIDER
-ExecStartPre=-/usr/bin/docker rm -f kubelet
-ExecReload=/usr/bin/docker restart kubelet
+ExecStartPre=-{{ docker_bin_dir }}/docker rm -f kubelet
+ExecReload={{ docker_bin_dir }}/docker restart kubelet
 Restart=always
 RestartSec=10s
 

roles/kubernetes/node/templates/manifests/kube-proxy.manifest.j2

@@ -11,6 +11,13 @@ spec:
   - name: kube-proxy
     image: {{ hyperkube_image_repo }}:{{ hyperkube_image_tag }}
     imagePullPolicy: {{ k8s_image_pull_policy }}
+    resources:
+      limits:
+        cpu: {{ kube_proxy_cpu_limit }}
+        memory: {{ kube_proxy_memory_limit }}
+      requests:
+        cpu: {{ kube_proxy_cpu_requests }}
+        memory: {{ kube_proxy_memory_requests }}
     command:
     - /hyperkube
     - proxy

roles/kubernetes/node/templates/manifests/nginx-proxy.manifest.j2

@@ -11,6 +11,13 @@ spec:
   - name: nginx-proxy
     image: {{ nginx_image_repo }}:{{ nginx_image_tag }}
     imagePullPolicy: {{ k8s_image_pull_policy }}
+    resources:
+      limits:
+        cpu: {{ nginx_cpu_limit }}
+        memory: {{ nginx_memory_limit }}
+      requests:
+        cpu: {{ nginx_cpu_requests }}
+        memory: {{ nginx_memory_requests }}
     securityContext:
       privileged: true
     volumeMounts: