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/network_plugin/canal/templates/canal-node.yml.j2

@@ -49,6 +49,13 @@ spec:
         - name: flannel
           image: "{{ flannel_image_repo }}:{{ flannel_image_tag }}"
           imagePullPolicy: {{ k8s_image_pull_policy }}
+          resources:
+            limits:
+              cpu: {{ flannel_cpu_limit }}
+              memory: {{ flannel_memory_limit }}
+            requests:
+              cpu: {{ flannel_cpu_requests }}
+              memory: {{ flannel_memory_requests }}
           env:
             # Cluster name
             - name: CLUSTER_NAME
@@ -119,6 +126,13 @@ spec:
         - name: calico-node
           image: "{{ calico_node_image_repo }}:{{ calico_node_image_tag }}"
           imagePullPolicy: {{ k8s_image_pull_policy }}
+          resources:
+            limits:
+              cpu: {{ calico_node_cpu_limit }}
+              memory: {{ calico_node_memory_limit }}
+            requests:
+              cpu: {{ calico_node_cpu_requests }}
+              memory: {{ calico_node_memory_requests }}
           env:
             # The location of the etcd cluster.
             - name: ETCD_ENDPOINTS