Added update script

Docker-container-on-Ubuntu-16.04-LTS.md

@@ -101,6 +101,27 @@ sudo docker pull linuxserver/radarr
 sudo systemctl restart docker-radarr
 ```
 
+If you want to automate this, you can use the following script (let it run with a systemd timer):
+
+```bash
+#!/bin/bash
+
+images=(     linuxserver/jackett  linuxserver/radarr  linuxserver/sonarr )
+containers=( jackett              radarr              sonarr             )
+services=(   docker-jackett       docker-radarr       docker-sonarr      )
+
+for ((i=0; i<${#images[*]}; i++)); do
+    echo "Pulling docker image: ${images[i]}"
+    docker pull ${images[i]}
+    if [[ $(docker inspect --type=image --format='{{.Id}}' ${images[i]}) != $(docker inspect --type=container --format='{{.Image}}' ${containers[i]}) ]]; then
+        echo "Restarting service: ${services[i]}"
+        systemctl restart ${services[i]}
+    fi
+done
+```
+
+Modify the variables `images`, `containers` and `services` according to your system. This script will only restart a service/container if the docker image was updated by `docker pull`.
+
 # Doing some cleanup
 
 With these commands you can do some cleanup of docker images and containers: