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/calico/rr/templates/calico-rr.service.j2

@@ -5,8 +5,8 @@ Requires=docker.service
 
 [Service]
 EnvironmentFile=/etc/calico/calico-rr.env
-ExecStartPre=-/usr/bin/docker rm -f calico-rr
-ExecStart=/usr/bin/docker run --net=host --privileged \
+ExecStartPre=-{{ docker_bin_dir }}/docker rm -f calico-rr
+ExecStart={{ docker_bin_dir }}/docker run --net=host --privileged \
  --name=calico-rr \
  -e IP=${IP} \
  -e IP6=${IP6} \
@@ -16,12 +16,13 @@ ExecStart=/usr/bin/docker run --net=host --privileged \
  -e ETCD_KEY_FILE=${ETCD_KEY_FILE} \
  -v /var/log/calico-rr:/var/log/calico \
  -v {{ calico_cert_dir }}:{{ calico_cert_dir }}:ro \
+ --memory={{ calico_rr_memory_limit|regex_replace('Mi', 'M') }} --cpu-shares={{ calico_rr_cpu_limit|regex_replace('m', '') }} \
  {{ calico_rr_image_repo }}:{{ calico_rr_image_tag }}
 
 Restart=always
 RestartSec=10s
 
-ExecStop=-/usr/bin/docker stop calico-rr
+ExecStop=-{{ docker_bin_dir }}/docker stop calico-rr
 
 [Install]
 WantedBy=multi-user.target