My brain-dump of random code/configuration.

27 Apr 2013

Automated Backups for Chef Server

In this article I will share my setup, I use to backup chef server. In the best case, you have a dedicated machine, which has network access to your chef server. Otherwise you will have to additionally use a different backup program like rsnapshot or duplicity to backup the created export directory. In my case I use a raspberry pie with a hdd docking station and a power saving harddrive

To get started you will need ruby on the backup machine. I prefer using rvm for this job. Feel free to choose your preferred way:

$ curl -L https://get.rvm.io | bash -s stable --autolibs=enabled

To create the backup, I use the great knife-backup gem of Marius Ducea:

$ gem install knife-backup

Then add these scripts to your system:

$ mkdir -p ~/bin && cd ~/bin
$ wget http://blog.higgsboson.tk/downloads/code/chef-backup/backup-chef.sh
$ wget http://blog.higgsboson.tk/downloads/code/chef-backup/restore-chef.sh
$ chmod +x {backup,restore}-chef.sh
# optional: load rvm
source "$HOME/.rvm/scripts/rvm" || source "/usr/local/rvm/scripts/rvm"

cd /tmp

BACKUP=/path/to/your/backup #<--- EDIT THIS LINE
TMPDIR=/tmp/$(mktemp -d chef-backup-XXXX)

trap "rm -rf '$TMPDIR'" INT QUIT TERM EXIT
knife --config $HOME/.chef/knife-backup.rb backup export -D . >/dev/null
tar -cjf "$BACKUP/$(date +%m.%d.%Y).tar.bz2" .
# keep the last X backups
ls -t "$BACKUP" | tail -n+$MAX_BACKUPS | xargs rm -f

if [ "$#" -eq 0 ]; then
    echo "USAGE: $0 /path/to/backup"
    exit 1

source "$HOME/.rvm/scripts/rvm" || source "/usr/local/rvm/scripts/rvm"

cd /tmp
TMPDIR=/tmp/$(mktemp -d chef-restore-XXXX)

cd "$TMPDIR"
trap "rm -rf '$TMPDIR'" INT QUIT TERM EXIT
tar xf $1
knife --config $HOME/.chef/knife-backup.rb backup restore -D .

Modify BACKUP variable to match your backup destination. Next you will need a knife.rb to get access to your server. I suggest to create a new client:

$ mkdir -p ~/.chef
$ knife client create backup --admin --file "$HOME/.chef/backup.pem"
$ cat <<'__EOF__' >> ~/.chef/knife-backup.rb
log_level                :info
log_location             STDOUT
node_name                'backup'
client_key               "#{ENV["HOME"]}/.chef/backup.pem"
chef_server_url          'https://chef.yourdomain.tld' # EDIT HERE
syntax_check_cache_path  "#{ENV["HOME"]}.chef/syntax_check_cache"
$ knife role list # test authentication

Now test the whole setup, by running the backup-chef.sh script:

$ ~/bin/backup-chef.sh

It should create a tar file in the backup directory.

If everything works, you can add a cronjob to automate this.

$ crontab -e
@daily $HOME/bin/backup-chef.sh

To restore a backup simply run (where DATE is the date of the backup)

$ ~/bin/restore-chef.sh /path/to/backup/DATE.tar.bz2

That’s all folks!

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