20 July 2017

Copy IPFire Backup to Synology Diskstation

by Stefan Ferstl

Running IPFire instead of a cheap plastic router is a good thing. But when your IPFire’s disk crashes, all the little settings that you have made over several years are lost (think of the last “smart” device that you allowed WIFI access). Fortunately, IPFire is able to create backups of its configuration in /var/ipfire/backup. Backups can be triggered via System -> Backup in the UI. Even better, IPFire automatically creates a backup before each update. So if you update IPFire regularly, you’ll also have recent backups.

In case of a disk failure all you need to do is buy a new disk, download and install IPFire and load the backup via a few UI clicks. However, “loading the backup” requires to backup the backup to a safer place beforehand. In this example, I’ll describe how to trigger the backup process directly, copy the backup files to a Synology Diskstation via SSH and how to setup the Diskstation to receive such backups. With a few tweaks the following steps will also work on other Unix-like systems.

Setup SSH Keys on the IPFire Host

Setup a SSH keypair, e.g. using ECDSA with 521 bit keys

ssh-keygen -t ecdsa -b 521

Configure Synology Diskstation to Receive the Backup

In the Diskstation UI:
- Create a dedicated user for the Backup, e.g. “ipfire”
- Give the user permission on the shared folder which stores the backup

# create a home directory for the user (use the group that you assigned in the Diskstation UI)
mkdir -p /home/ipfire
chown ipfire:<mygroup> /home/ipfire
chmod o-rx /home/ipfire

# Edit /etc/passwd and set the home directory and a login shell
ipfire:x:<userid>:<groupid>:ipfire backup:/home/ipfire:/bin/sh

# Create the .ssh folder
mkdir .ssh
chmod go-rx .ssh
touch ~/.ssh/authorized_keys

Copy the public key from IPFire (content of /root/.ssh/id_ecdsa.pub on the IPFire host) into /home/ipfire/.ssh/authorized_keys

Setup a Daily Backup on the IPFire Host

Create a backup script, e.g. copy-backup.sh:

#/bin/bash
  
USER=ipfire
HOST=diskstation
SOURCE_DIR=/var/ipfire/backup
ADDON_DIR="${SOURCE_DIR}/addons"
BACKUP_SCRIPT="${SOURCE_DIR}/bin/backup.pl"
DESTINATION_DIR=/path/to/the/backup/directory
LOG_FILE=/var/log/copy_backup.log
  
function log() {
  message="$1"
  
  echo "$(date +"%Y-%m-%d %T"): ${message}"  >> "${LOG_FILE}" 2>&1
}
  
log "Creating Backup of ${SOURCE_DIR}"
# "include" will add the log files to the backup
"${BACKUP_SCRIPT}" include
log "Finished with exit code $?"
  
# Backup all addons
for f in $(find "${ADDON_DIR}/includes" -type f); do
  addon=$(basename $f)
  log "Creating backup of Addon '$addon'"
  "${BACKUP_SCRIPT}" addonbackup "$addon"
  log "Finished with exit code $?"
done
  
log "Copying backup to ${HOST}:${DESTINATION_DIR}"
scp -r "${SOURCE_DIR}" ${USER}@${HOST}:"${DESTINATION_DIR}" >> "${LOG_FILE}" 2>&1
log "Finished with exit code $?."
  
log "Backup done."

Link the backup script in fcron.daily

cd /etc/fcron.daily
ln -s /root/copy-backup.sh copy-backup

Possible Improvements of this Post

Describe how to setup IPFire from scratch and restore the backup
/root and /etc/fcron.* are not part of the backup. Describe how to include them into the backup

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