Backup Configuration for Obshtestvo.bg Infrastructure

Contents

• Makefile updates the scripts
• host/
  • do_backup.sh - does backup for the host
  • backup.sh - collects backups for the containers
• cont/$CONTAINER the backup script for each container

Backup storage/strategy

On marla.ludost.net, the backup is initiated every morning at 6:06am and is kept for one week. All backups are full backups, no incremental or differential ones.

How to add a container to be backed up

Do nothing. The container setup script adds the needed scripts and keys where needed. The do_backup.sh script gets taken from templates/do_backup.sh of the github.com/obshtestvo/create-lxc repository, and the authorized_keys gets copied from the host, which contains what's needed.

How to modify what's being backed up

DO NOT MODIFY the /do_backup.sh script directly in the container except for test purposes. Otherwise it will be overwritten at some point with the version found in this repo.

In this repository, in cont/ create a directory with the name of the container, put there a modified do_backup.sh and when done run make from the top level directory of this repository, to install it. A clone of this repo can be found in /root/backup-sys on koi.obshtestvo.bg. Do not forget to do a git pull before running make.

If you have a hard time understanding the script, DO NOT TOUCH IT and ask someone else.

Also, please note NOT TO PUT ANY PASSWORDS OR OTHER SECRET DATA IN THE REPO, as we don't want to be known as another example of people leaving their passwords/secrets for everyone to see on github.

Restoring from backup

• If koi.obshtestvo.bg had died or you need something not from the latest backup, ask Vasil Kolev for the encrypted files.
  • TODO some more people need access
  • Decrypt the file with the key on koi.obshtestvo.bg
    • If yo you don't have the passphrase for the key, ask Vasil
    • Vasil also has a backup of the key
    • TODO More people should have the key and passphrase
• OR
  • If you need the latest backup, look in /backup of the container for the unencrypted files, or /backup on the host
• Take the needed archives/files and restore what you need

How Does It Work

Backup initiation, stage 1

A script gets triggered by cron for user bckp on marla.ludost.net, which logs into koi.obshtestvo.bg with a specific ssh key and triggers /usr/local/sbin/backup.sh. That script prepares the backups and pipes them in tar format to stdout. This is described in /root/.ssh/authorized_keys.

/usr/local/sbin/backup.sh

This script triggers the backup creation using ssh in all containers it finds, calling /do_backup.sh over ssh. For this to work for the container, in it in /root/.ssh/authrorized_keys there should be a line that allows calling /do_backup.sh using the backup key (which can be located on koi.obshtestvo.bg in /root/.ssh/).

All do_backup.sh scripts create a /backup directory in the container, which then gets encrypted using gpg with a key that can be found in /root/gnupg:

pub   4096R/FDA82047 2014-09-22
uid                  Obshtestvo Backup <[email protected]>
sub   4096R/09EDA521 2014-09-22

The encrypted files are sent in tar format to stdout.

Per-container /do_backup.sh

For this script to be able to work, the following is required in the container:

• In /root/.ssh/authorized_keys, an entry for the backup key should be made, starting with command="/do_backup.sh",no-pty,no-port-forwarding,no-X11-forwarding,no-agent-forwarding.
• If mysql databases are available in the container, the default debian config files should be available in /etc/mysql/debian.cnf.
• If pgsql databases are available in the container, the database has to run as the postgres user and sudo must be available.