New step "updatecheck" to check if a new version is available

seqs/element-web.sh

@@ -19,6 +19,28 @@ step_config() {
   fi
 }
 
+step_18_info() { echo "Check for updates"; }
+step_18_alias() { ALIAS="updatecheck"; }
+step_18() {
+  shift
+  local latestVersion=
+  if [ ! -z $1 ] ; then
+    latestVersion="$1"
+  else
+    latestVersion=$(curl --silent "$latestUrl" | grep -Po '"tag_name": "v\K.*?(?=")')
+  fi
+
+  local isInstalled=$(grep -E "${latestVersion}" "${ELEMENT_WEB_LOC}/version" >>/dev/null && echo "1" || echo "0")
+  if [ $isInstalled -eq 1 ] ; then
+    echo " [I] Version $latestVersion is already installed"
+    return 1
+  else
+    echo " [I] Update to $latestVersion available"
+  fi
+  return 0
+}
+
+
 step_20_info() { 
   echo -n "Create a backup [ELEMENT WEB ROOT]"
   if [ $CONFIG -ne 0 ] ; then