fix handling of incremental backups with xtrabackup

Author: fraenki

manifests/backup/xtrabackup.pp

@@ -51,9 +51,18 @@
   }
 
   if $incremental_backups {
+    # Warn if old backups are removed too soon. Incremental backups will fail
+    # if the full backup is no longer available.
+    if ($backuprotate.convert_to(Integer) < 7) {
+      warning(translate('The value for `backuprotate` is too low, it must be set to at least 7 days when using incremental backups.'))
+    }
+
+    # The --target-dir uses a more predictable value for the full backup so
+    # that it can easily be calculated and used in incremental backup jobs.
+    # Besides that it allows to have multiple full backups.
     cron { 'xtrabackup-weekly':
       ensure  => $ensure,
-      command => "/usr/local/sbin/xtrabackup.sh --target-dir=${backupdir} ${additional_cron_args}",
+      command => "/usr/local/sbin/xtrabackup.sh --target-dir=${backupdir}/$(date +\\%F)_full ${additional_cron_args}",
       user    => 'root',
       hour    => $time[0],
       minute  => $time[1],
@@ -62,9 +71,19 @@
     }
   }
 
+  # Wether to use GNU or BSD date format.
+  case $::osfamily {
+    'FreeBSD','OpenBSD': {
+      $dateformat = '$(date -v-sun +\\%F)_full'
+    }
+    default: {
+      $dateformat = '$(date -d "last sunday" +\\%F)_full'
+    }
+  }
+
   $daily_cron_data = ($incremental_backups) ? {
     true  => {
-      'directories' => "--incremental-basedir=${backupdir} --target-dir=${backupdir}/$(date +\\%F_\\%H-\\%M-\\%S)",
+      'directories' => "--incremental-basedir=${backupdir}/${dateformat} --target-dir=${backupdir}/$(date +\\%F_\\%H-\\%M-\\%S)",
       'weekday'     => '1-6',
     },
     false => {

spec/classes/mysql_backup_xtrabackup_spec.rb

@@ -31,7 +31,7 @@ class { 'mysql::server': }
           is_expected.to contain_cron('xtrabackup-weekly')
             .with(
               ensure: 'present',
-              command: '/usr/local/sbin/xtrabackup.sh --target-dir=/tmp/$(date +\%F_\%H-\%M-\%S) --backup',
+              command: '/usr/local/sbin/xtrabackup.sh --target-dir=/tmp/$(date +\%F)_full --backup',
               user: 'root',
               hour: '23',
               minute: '5',
@@ -41,10 +41,16 @@ class { 'mysql::server': }
         end
 
         it 'contains the daily cronjob for weekdays 1-6' do
+          dateformat = case facts[:osfamily]
+                       when 'FreeBSD', 'OpenBSD'
+                         '$(date -v-sun +\%F)_full'
+                       else
+                         '$(date -d "last sunday" +\%F)_full'
+                       end
           is_expected.to contain_cron('xtrabackup-daily')
             .with(
               ensure: 'present',
-              command: '/usr/local/sbin/xtrabackup.sh --incremental-basedir=/tmp --target-dir=/tmp/$(date +\%F_\%H-\%M-\%S) --backup',
+              command: "/usr/local/sbin/xtrabackup.sh --incremental-basedir=/tmp/#{dateformat} --target-dir=/tmp/$(date +\\\%F_\\\%H-\\\%M-\\\%S) --backup",
               user: 'root',
               hour: '23',
               minute: '5',
@@ -84,11 +90,18 @@ class { 'mysql::server': }
           { additional_cron_args: '--backup --skip-ssl' }.merge(default_params)
         end
 
+        dateformat = case facts[:osfamily]
+                     when 'FreeBSD', 'OpenBSD'
+                       '$(date -v-sun +\%F)_full'
+                     else
+                       '$(date -d "last sunday" +\%F)_full'
+                     end
+
         it 'contains the weekly cronjob' do
           is_expected.to contain_cron('xtrabackup-weekly')
             .with(
               ensure: 'present',
-              command: '/usr/local/sbin/xtrabackup.sh --target-dir=/tmp/$(date +\%F_\%H-\%M-\%S) --backup --skip-ssl',
+              command: '/usr/local/sbin/xtrabackup.sh --target-dir=/tmp/$(date +\%F)_full --backup --skip-ssl',
               user: 'root',
               hour: '23',
               minute: '5',
@@ -101,7 +114,7 @@ class { 'mysql::server': }
           is_expected.to contain_cron('xtrabackup-daily')
             .with(
               ensure: 'present',
-              command: '/usr/local/sbin/xtrabackup.sh --incremental-basedir=/tmp --target-dir=/tmp/$(date +\%F_\%H-\%M-\%S) --backup --skip-ssl',
+              command: "/usr/local/sbin/xtrabackup.sh --incremental-basedir=/tmp/#{dateformat} --target-dir=/tmp/$(date +\\\%F_\\\%H-\\\%M-\\\%S) --backup --skip-ssl",
               user: 'root',
               hour: '23',
               minute: '5',