Hi all
I’ve slightly hacked the backup script to include a full rsync backup to a secondary server that has a full MIAB install, and simply is offline [in terms of dovecot, postfix, and php7.2-fpm] and is ready to be enabled at the click of a button should your primary server go down.
This could happen for any number of reasons, and since it only adds about 20 to 30 seconds to the nightly backup script [or slightly more if your server is user by a bunch of people], I thought I’d share it here.
This guide is for MIAB v0.4 / Ubuntu 18.
1] Fully install an empty MIAB server on a new machine in a remote location [as independent as possible from the main one of course]
2] on the newly created empty secondary node:
systemctl disable dovecot
systemctl disable postfix
systemctl disable php7.2-fpm
mv /home/user-data /home/user-data-initial
3] on the primary node:
enter the user where you installed MIAB as and locate the “mailinabox” folder [with contents such as Changelog.MD, etc…] and cd into it
nano +254 ./management/backup.py
change the pre-backup portion of the script so that you get this:
pre_script = os.path.join(backup_root, 'before-backup')
if os.path.exists(pre_script):
shell('check_call',
['bash', pre_script, config["target"]],
env=env)
nano /home/user-data/backup/before-backup
and paste the following into it:
#!/usr/bin/env bash
rsync -Pave "ssh -i /home/user-data/backup/push-backups-to-standby-server" /home/user-data/ root@SECONDARY-NODE-IP:/home/user-data/ &> /dev/null
changing SECONDARY-NODE-IP with the public ipv4 of the secondary node of course.
ssh-keygen -t rsa -b 8192
and at the prompt specify to save it into /home/USER/.ssh/push-backups-to-standby-server changing USER with the username that performed the MIAB install, the same one we located earlier in these instructions.
cat /home/USER/.ssh/push-backups-to-standby-server.pub
and copy the output on the second server’s /root/.ssh/authorized-keys file with nano. If there’s no /root/.ssh/ dir, simply mkdir /root/.ssh before you do the nano part.
Now back on your primary node sudo -i or log in as root.
ssh -i /home/user-data/backup/push-backups-to-standby-server root@SECONDARY-NODE-IP
and press yes if you get prompted to continue with the initial connection.
That should do it!
If you ever need to make the secondary node live because your first one has any problems, simply [from the secondary node as root]:
systemctl enable php7.2-fpm
systemctl enable dovecot
systemctl enable postfix
then stay on the secondary server and log in as the user that has performed the empty MIAB initially [where the “mailinabox” folder with Changelog.MD is], and then execute:
sudo mailinabox
to have MIAB pick up the new data. Then update your main MIAB domain’s DNS accordingly [glue records and such]. Remember to keep an eye on the status checks page of your secondary server to see if everything is running ok.
Back to the initial guide, before anything bad ever happens, the first rsync will take a long time so you might want to execute one manually [with services running, it’s ok, as it’s just an initial sync, a real one will follow later starting on the first night] by running:
bash /home/user-data/backup/before-data
as root from the primary node.
The command won’t output anything, but you’ll see the progress happening on your secondary node by executing [on the secondary node of course]:
du -sh /home/user-data
This complexity is due to this “issue”
You’ll need to probably re-run part of these steps on the primary node when you upgrade mailinabox, most likely only the step where you modify the backup.py file though, everything else should be persistent.
I’ve been running this for a few days now and works amazingly well! Let me know what you think!