docs: how to check we backup properly

Fixes: #3390

doc/maintenance/backup_check.rst

@@ -0,0 +1,107 @@
+.. _backup_check:
+
+Check that Fedora Copr Backups are OK
+=====================================
+
+This document explains how Fedora Copr backups are performed, so we can
+periodically verify that everything is in place and functioning properly.  For
+disaster recovery, refer to :ref:`backup_recovery`.
+
+Copr Backend
+------------
+
+The backend storage uses a complex RAID setup to provide redundancy directly on
+the server (in EC2).  Backups are then
+`synchronized periodically <https://pagure.io/fedora-infra/ansible/blob/81f81668cc0ea3101cf74d56401aad3c1354f788/f/roles/rsnapshot-push/tasks/main.yml#_67>`_
+to the storinator01 host as incremental backups via rsnapshot.
+To verify backend backups, you should:
+
+  1. Confirm the timestamp of the most recent backup **start**.
+  2. Choose a random build that completed just before that time.
+  3. Verify that this build was successfully backed up to storinator01.
+
+Here comes more detailed guide:
+
+1) SSH into the ``copr-be`` machine and review the ``/var/log/cron`` file.  You
+   may want to check the ``crontab -l`` output first to confirm the backup
+   schedule (typically Fridays though) and open an older compressed Cron log
+   file::
+
+    $ xz -d < /var/log/cron-20241101.xz | grep '(copr) CMD'
+    ...
+    Nov  1 03:00:02 copr-be CROND[3482216]: (copr) CMD (ionice --class=idle /usr/local/bin/rsnapshot_copr_backend >/dev/null)
+    ...
+
+   The last backup started on **November 1, 3:00 AM**.
+
+   The backup process typically takes several days.  If there’s no corresponding
+   ``CMDEND`` entry in the cron logs, it indicates that the backup is still in
+   progress, and the build ID we’re trying to verify as backed up may not yet be
+   included. Wait for it to complete.  Or check the previous backup increment
+   instead (that means poke at ``/var/log/cron-20241025.xz``).
+
+2) Find an appropriate build ID that finished "just before" that time above.
+   For instance in the ``@copr/copr-pull-requests`` or ``@copr/copr-dev``
+   projects.  Good candidate is `8185411 <https://copr.fedorainfracloud.org/coprs/g/copr/copr-pull-requests/build/8185411/>`_.
+
+3) SSH into the `storinator01` box and locate the latest incremental backup
+   (note that the sub-projects matter, ``copr-pull-requests:pr:3473`` in our
+   case)::
+
+    $ find /srv/nfs/copr-be/copr-be-copr-user/backup/.sync/var/lib/copr/public_html/results/@copr/copr-pull-requests:pr:3473 | grep 8185411 | grep rpm$
+    /srv/nfs/copr-be/copr-be-copr-user/backup/.sync/var/lib/copr/public_html/results/@copr/copr-pull-requests:pr:3473/epel-8-x86_64/08185411-copr-rpmbuild/copr-builder-1.1-1.git.3.8adcc0d.el8.x86_64.rpm
+    /srv/nfs/copr-be/copr-be-copr-user/backup/.sync/var/lib/copr/public_html/results/@copr/copr-pull-requests:pr:3473/epel-8-x86_64/08185411-copr-rpmbuild/copr-rpmbuild-1.1-1.git.3.8adcc0d.el8.src.rpm
+    /srv/nfs/copr-be/copr-be-copr-user/backup/.sync/var/lib/copr/public_html/results/@copr/copr-pull-requests:pr:3473/epel-8-x86_64/08185411-copr-rpmbuild/copr-rpmbuild-1.1-1.git.3.8adcc0d.el8.x86_64.rpm
+    /srv/nfs/copr-be/copr-be-copr-user/backup/.sync/var/lib/copr/public_html/results/@copr/copr-pull-requests:pr:3473/epel-9-x86_64/08185411-copr-rpmbuild/copr-builder-1.1-1.git.3.8adcc0d.el9.x86_64.rpm
+    ...
+
+This confirms the backups are working correctly.  While you’re on storinator,
+ensure there is adequate free space on the filesystem by running
+``df -h /srv/nfs/copr-be``.
+
+
+Copr Frontend
+-------------
+
+For Frontend, we backup the PostgreSQL database (hourly).  Check
+``/etc/cron.d/cron-backup-database-coprdb`` cron config, and the corresponding
+``/backups`` directory.  That one should have the current timestamp, like::
+
+    [root@copr-fe ~][PROD]# ls -alh /backups/
+    total 662M
+    drwxr-xr-x. 1 postgres root       50 Nov  5 01:21 .
+    dr-xr-xr-x. 1 root     root      160 Nov 28  2023 ..
+    -rw-r--r--. 1 postgres postgres 662M Nov  5 01:21 coprdb-2024-11-05.dump.xz
+
+If we provide such an updated tarball, `rdiff-backup
+<https://docs.fedoraproject.org/en-US/infra/sysadmin_guide/rdiff-backup/>`_
+periodically comes and pulls the backups "out"; as long as the box is in an
+appropriate `Ansible group
+<https://pagure.io/fedora-infra/ansible/blob/81f81668cc0ea3101cf74d56401aad3c1354f788/f/inventory/backups#_4>`_
+and we `configure
+<https://pagure.io/fedora-infra/ansible/blob/81f81668cc0ea3101cf74d56401aad3c1354f788/f/inventory/host_vars/copr-fe.aws.fedoraproject.org#_6>`_
+the backup dir.
+
+For Frontend data volume, we also do automatic volume snapshots (see Copr Keygen
+info below for more info).
+
+
+Copr Keygen
+-----------
+
+We don't do filesystem backups (rsync) there.  The important data —keypairs— are
+stored on a separate volume ``/var/lib/copr-keygen``, and periodically
+snapshotted in EC2.  Check for `the volume
+<https://us-east-1.console.aws.amazon.com/ec2/home?region=us-east-1#VolumeDetails:volumeId=vol-0108e05e229bf7eaf>`_.
+
+We do snapshots to **Ohio**, ``us-east-2``!  Volume snapshots may be filtered
+with tag ``FedoraGroup=copr``.
+
+Copr DistGit
+------------
+
+Due to Copr's design (see :ref:`architecture <architecture>`), Copr DistGit data
+is extensive, measuring in terabytes, yet it’s not critical enough to require
+formal backups.  We anyway at least do periodic snapshots like with Copr Keygen
+above.  In the event of a complete failure, we would restore from there — or
+simply initialize a new, empty volume.

doc/maintenance_documentation.rst

@@ -17,6 +17,7 @@ This section contains information about maintenance topics. You may also be inte
    Fedora Copr hypervisors <maintenance/hypervisors>
    Fedora Copr outage announcements <maintenance/announce_outage>
    Fedora Copr credentials <maintenance/credentials>
+   Check that backups are OK <maintenance/backup_check>
 
 
 .. toctree::