Add an update script for Linux

update.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+GROCY_RELEASE_URL=https://releases.grocy.info/latest
+
+
+echo Start updating grocy
+
+set -e
+shopt -s extglob
+pushd `dirname $0` > /dev/null
+
+backupBundleFileName="backup-`date +%d-%m-%Y-%H-%M-%S`.tgz"
+echo Making a backup of the current installation in /data/backups/$backupBundleFileName
+mkdir -p ./data/backups > /dev/null
+tar -zcvf ./data/backups/$backupBundleFileName --exclude ./data/backups . > /dev/null
+find ./data/backups/*.tgz -mtime +60 -type f -delete
+
+echo Deleting everything except /data and this script
+rm -rf !(data|update.sh) > /dev/null
+
+echo Emptying /data/viewcache
+rm -rf ./data/viewcache/* > /dev/null
+
+echo Downloading latest release
+rm -f ./grocy-latest.zip > /dev/null
+wget $GROCY_RELEASE_URL -q -O ./grocy-latest.zip > /dev/null
+
+echo Unzipping latest release
+unzip -o ./grocy-latest.zip > /dev/null
+rm -f ./grocy-latest.zip > /dev/null
+
+popd > /dev/null
+
+echo Finished updating grocy