This sets a global BORG_UNDER_CRON=1 environment variable for
production hosts and makes the borg-backup script send an email if any
part of the backup job appears to fail (this avoids spamming ourselves
if we're testing backups, etc).
We should ideally never get this email, but if we do it's something we
want to investigate quickly. There's nothing worse than thinking
backups are working when they aren't.
Change-Id: Ibb63f19817782c25a5929781b0f6342fe4c82cf0
It's not obvious, but the if statements can change the PIPESTATUS
meaning we're not matching what we think we're matching. Save the
pipestatus of the backup commands so we exit the backup script with
the right code.
Change-Id: I83c7db45d3622067eb05107e26fbdc7a8aeecf63
Add facility to borg-backup role to run a command and save the output
of it to a separate archive file during the backup process.
This is mostly useful for database backups. Compressed on-disk logs
are terrible for differential backups because revisions have
essentially no common data. By saving the uncompressed stream
directly from mysqldump, we allow borg the chance to de-duplicate,
saving considerable space on the backup servers.
This is implemented for our ansible-managed servers currently doing
dumps. We also add it to the testinfra.
This also separates the archive names for the filesystem and stream
backup with unique prefixes so they can be pruned separately.
Otherwise we end up keeping only one of the stream or filesystem
backups which isn't the intention. However, due to issues with
--append-only mode we are not issuing prune commands at this time.
Note the updated dump commands are updated slightly, particularly with
"--skip-extended-insert" which was suggested by mordred and
significantly improves incremental diff-ability by being slightly more
verbose but keeping much more of the output stable across dumps.
Change-Id: I500062c1c52c74a567621df9aaa716de804ffae7
After a successful backup run, perform a prune step to slim down to
keep the last 7 days, the last 4 weeks and the last 12 months of
backups.
Change-Id: I98d60319e333d22b3b48214d3dd9136e255a341f
This adds roles to implement backup with borg [1].
Our current tool "bup" has no Python 3 support and is not packaged for
Ubuntu Focal. This means it is effectively end-of-life. borg fits
our model of servers backing themselves up to a central location, is
well documented and seems well supported. It also has the clarkb seal
of approval :)
As mentioned, borg works in the same manner as bup by doing an
efficient back up over ssh to a remote server. The core of these
roles are the same as the bup based ones; in terms of creating a
separate user for each host and deploying keys and ssh config.
This chooses to install borg in a virtualenv on /opt. This was chosen
for a number of reasons; firstly reading the history of borg there
have been incompatible updates (although they provide a tool to update
repository formats); it seems important that we both pin the version
we are using and keep clients and server in sync. Since we have a
hetrogenous distribution collection we don't want to rely on the
packaged tools which may differ. I don't feel like this is a great
application for a container; we actually don't want it that isolated
from the base system because it's goal is to read and copy it offsite
with as little chance of things going wrong as possible.
Borg has a lot of support for encrypting the data at rest in various
ways. However, that introduces the possibility we could lose both the
key and the backup data. Really the only thing stopping this is key
management, and if we want to go down this path we can do it as a
follow-on.
The remote end server is configured via ssh command rules to run in
append-only mode. This means a misbehaving client can't delete its
old backups. In theory we can prune backups on the server side --
something we could not do with bup. The documentation has been
updated but is vague on this part; I think we should get some hosts in
operation, see how the de-duplication is working out and then decide
how we want to mange things long term.
Testing is added; a focal and bionic host both run a full backup of
themselves to the backup server. Pretty cool, the logs are in
/var/log/borg-backup-<host>.log.
No hosts are currently in the borg groups, so this can be applied
without affecting production. I'd suggest the next steps are to bring
up a borg-based backup server and put a few hosts into this. After
running for a while, we can add all hosts, and then deprecate the
current bup-based backup server in vexxhost and replace that with a
borg-based one; giving us dual offsite backups.
[1] https://borgbackup.readthedocs.io/en/stable/
Change-Id: I2a125f2fac11d8e3a3279eb7fa7adb33a3acaa4e
