Free ports 80 and 443 on Synology NAS

free_ports.sh

#! /bin/bash

# NEWLY ADDED BACKUP FUNCTIONALITY IS NOT FULLY TESTED YET, USE WITH CARE, ESPECIALLY DELETION
# Developed for DSM 6 - 7.0.1. Not tested on other versions.
# Steps to install
# Save this script in one of your shares
# Edit it according to your requirements
# Backup /usr/syno/share/nginx/ as follows:
# # cd /usr/syno/share/
# # tar cvf ~/nginx.tar nginx
# Run this script as root
# Reboot and ensure everything is still working
# If not, restore the backup and post a comment on this script's gist page
# If it did, schedule it to run as root at boot
#   through Control Panel -> Task Scheduler

HTTP_PORT=81
HTTPS_PORT=444

BACKUP_FILES=true # change to false to disable backups
BACKUP_DIR=/volume1/apps/free_ports/backup
DELETE_OLD_BACKUPS=false # change to true to automatically delete old backups.
KEEP_BACKUP_DAYS=30

DATE=$(date +%Y-%m-%d-%H-%M-%S)
CURRENT_BACKUP_DIR="$BACKUP_DIR/$DATE"

if [ "$BACKUP_FILES" == "true" ]; then
  mkdir -p "$CURRENT_BACKUP_DIR"
  cp /usr/syno/share/nginx/*.mustache "$CURRENT_BACKUP_DIR"
fi

if [ "$DELETE_OLD_BACKUPS" == "true" ]; then
  find "$BACKUP_DIR/" -type d -mtime +$KEEP_BACKUP_DAYS -exec rm -r {} \;
fi

sed -i "s/^\([ \t]\+listen[ \t]\+[]:[]*\)80\([^0-9]\)/\1$HTTP_PORT\2/" /usr/syno/share/nginx/*.mustache
sed -i "s/^\([ \t]\+listen[ \t]\+[]:[]*\)443\([^0-9]\)/\1$HTTPS_PORT\2/" /usr/syno/share/nginx/*.mustache

if which synoservicecfg; then
  synoservicecfg --restart nginx
else
  synosystemctl restart nginx
fi

echo "Made these changes:"

diff /usr/syno/share/nginx/ $CURRENT_BACKUP_DIR 2>&1 | tee $CURRENT_BACKUP_DIR/changes.log

I asked chatgpt to look at the script, explain in detail why it would no longer work on DSM 7.2+ and suggest some changes to fix. This was the result: https://gist.github.com/Damotron500/18d7e114df22631a428c9f44eb8b3b3d
It works for me. (DSM 7.2.2). Linking it here in case anyone wants to review. Its AI generated plagiarised from the original, so take with a pinch of salt.