Add update systemd job

update-bridgehead.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+service="bridgehead"
+# Creates logs
+log() {
+  echo "$(date +'%Y-%m-%d %T')" "$1:" "$2"
+}
+
+log "INFO" "Checking for updates of $service"
+# check prerequisites
+prerequisites="git docker docker-compose"
+for prerequisite in $prerequisites; do
+  $prerequisite --version 2>&1
+  is_available=$?
+  if [ $is_available -gt 0 ]; then
+    log "ERROR" "Prerequisite not fulfilled - $prerequisite is not available!"
+    exit 79
+  fi
+done
+# check if updates are available
+old_git_hash="$(git rev-parse --verify HEAD)"
+git fetch 2>&1
+git pull 2>&1
+new_git_hash="$(git rev-parse --verify HEAD)"
+git_updated="false"
+if [ "$old_git_hash" != "$new_git_hash" ]; then
+  log "INFO" "Pulled new changes from origin"
+  git_updated="true"
+fi
+docker_updated="false"
+for image in $(docker ps --filter "name=$service" --format {{.Image}}); do
+  log "INFO" "Checking for Updates of Image: $image"
+  if docker pull $image | grep "Downloaded newer image"; then
+    log "INFO" "$image updated."
+    docker_updated="true"
+  fi
+done
+if [ $git_updated = "true" ] || [ $docker_updated = "true" ]; then
+  log "INFO" "Due to previous updates now restarting $service@$1"
+  systemctl restart "$service@$1.service"
+fi
+log "INFO" "checking updates finished"
+exit 0