Merge pull request #143 from zalando/configurable-number-of-backups-t…

…o-retain-by-wal-e Make number of backups to retain configurable using environment
zalando · Apr 5, 2017 · adca420 · adca420
2 parents 539cc52 + d0b0f28
commit adca420
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Showing 3 changed files with 10 additions and 4 deletions.
diff --git a/postgres-appliance/configure_spilo.py b/postgres-appliance/configure_spilo.py
@@ -264,6 +264,7 @@ def get_placeholders(provider):
     placeholders.setdefault('PGHOME', os.path.expanduser('~'))
     placeholders.setdefault('APIPORT', '8008')
     placeholders.setdefault('BACKUP_SCHEDULE', '00 01 * * *')
+    placeholders.setdefault('BACKUP_NUM_TO_RETAIN', 2)
     placeholders.setdefault('CRONTAB', '[]')
     placeholders.setdefault('PGROOT', os.path.join(placeholders['PGHOME'], 'pgroot'))
     placeholders.setdefault('WALE_TMPDIR', os.path.abspath(os.path.join(placeholders['PGROOT'], '../tmp')))
@@ -381,7 +382,7 @@ def write_crontab(placeholders, path, overwrite):
                 return
 
     lines = ['PATH={}'.format(path)]
-    lines += ['{BACKUP_SCHEDULE} /postgres_backup.sh "{WALE_ENV_DIR}" "{PGDATA}"'.format(**placeholders)]
+    lines += ['{BACKUP_SCHEDULE} /postgres_backup.sh "{WALE_ENV_DIR}" "{PGDATA}" "{BACKUP_NUM_TO_RETAIN}"'.format(**placeholders)]
     lines += yaml.load(placeholders['CRONTAB'])
     lines += ['']  # EOF requires empty line for cron
 

diff --git a/postgres-appliance/launch.sh b/postgres-appliance/launch.sh
@@ -12,7 +12,7 @@ chown -R postgres:postgres "$PGLOG"
 
 if python3 /configure_spilo.py all; then
     (
-        sudo PATH="$PATH" -u postgres /patroni_wait.sh -t 3600 -- /postgres_backup.sh "$WALE_ENV_DIR" "$PGDATA"
+        sudo PATH="$PATH" -u postgres /patroni_wait.sh -t 3600 -- /postgres_backup.sh "$WALE_ENV_DIR" "$PGDATA" "$BACKUP_NUM_TO_RETAIN"
     ) &
 fi
 

diff --git a/postgres-appliance/postgres_backup.sh b/postgres-appliance/postgres_backup.sh
@@ -16,12 +16,17 @@ shift
 PGDATA=$1
 shift
 
+NUM_TO_RETAIN=$1
+shift
+
 IN_RECOVERY=$(psql -tXqAc "select pg_is_in_recovery()")
 [[ $IN_RECOVERY != "f" ]] && log "Cluster is in recovery, not running backup" && exit 0
 
-# leave only 2 base backups before creating a new one
+# leave at least 2 base backups before creating a new one
+[[ "$NUM_TO_RETAIN" -lt 2 ]] && NUM_TO_RETAIN=2
+
 # --aws-instance-profile flag is just ignored when running in GCE.
-envdir "${WALE_ENV_DIR}" wal-e --aws-instance-profile delete --confirm retain 2
+envdir "${WALE_ENV_DIR}" wal-e --aws-instance-profile delete --confirm retain "${NUM_TO_RETAIN}"
 
 # Ensure we don't have more workes than CPU's
 POOL_SIZE=4