borg-backup-server: add script for pruning borg backups

This adds a script that performs a manual pruning of backup
directories.

Change-Id: I9559bb8aeeef06b95fb9e172a2c5bfb5be5b480e

playbooks/roles/borg-backup-server/files/prune-borg-backups.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+
+set -e
+
+echo "This script will prune each archive in the backups of all backed up hosts"
+echo "Enter 'noop' to test, or 'prune' to actually prune"
+read -p "Operation: " borg_op
+
+if [[ ${borg_op} == 'noop' ]]; then
+    BORG_OP='--dry-run'
+elif [[ ${borg_op} == 'prune' ]]; then
+    BORG_OP=''
+else
+    echo "*** Invalid input"
+    exit 1
+fi
+
+pushd /opt/backups
+
+for u in borg-*; do
+    BORG_REPO=/opt/backups/$u/backup
+
+    sudo BORG_OP=${BORG_OP} BORG_RELOCATED_REPO_ACCESS_IS_OK=y BORG_REPO=${BORG_REPO} -u ${u} -s  <<'EOF'
+
+    # Look at all archives and strip the timestamp, leaving just the archive names
+    # We limit the prune by --prefix so each archive is considered separately
+    archives=$(/opt/borg/bin/borg list ${BORG_REPO} | awk '{$1 = substr($1, 0, length($1)-20); print $1}' | sort | uniq)
+
+    for prefix in ${archives};
+    do
+      echo
+      echo
+      echo "+------"
+      echo "| Pruning ${BORG_REPO} archive ${prefix}"
+      echo "+------"
+     /opt/borg/bin/borg prune --prefix ${prefix} ${BORG_OP} --verbose --list --show-rc --keep-daily 7 --keep-weekly 4 --keep-monthly 12
+    done
+
+EOF
+done

playbooks/roles/borg-backup-server/tasks/main.yaml

@@ -7,6 +7,14 @@
   include_role:
     name: install-borg
 
+- name: Install prune script
+  copy:
+    src: 'prune-borg-backups.sh'
+    dest: '/usr/local/bin/prune-borg-backups'
+    owner: root
+    group: root
+    mode: '0755'
+
 - name: Build all borg users from backup hosts
   set_fact:
     borg_users: '{{ borg_users }} + [ {{ hostvars[item]["borg_user"] }} ]'

testinfra/test_borg_backups.py

@@ -88,3 +88,11 @@ def test_borg_backup(host):
     # unmount it for sanity
     cmd = host.run('umount /opt/backups')
     assert cmd.succeeded
+
+def test_borg_server_prune(host):
+    hostname = host.backend.get_hostname()
+    if hostname.startswith('borg-backup-test'):
+        pytest.skip()
+
+    cmd = host.run('echo "prune" | /usr/local/bin/prune-borg-backups 2>&1 > /var/log/prune-borg-backups.log')
+    assert cmd.succeeded

zuul.d/system-config-run.yaml

@@ -357,6 +357,9 @@
       - playbooks/zuul/templates/host_vars/borg-backup
       - testinfra/test_borg_backups.py
     host-vars:
+      borg-backup01.region.provider.opendev.org:
+        host_copy_output:
+          '/var/log/prune-borg-backups.log': logs
       borg-backup-test01.opendev.org:
         host_copy_output:
           '/var/log/borg-backup-borg-backup01.region.provider.opendev.org.log': logs