Allow psycopg2 import failure if not actually running backup

Author: natefoo

defaults/main.yml

@@ -36,7 +36,7 @@ postgresql_backup_command: >-
   --rsync-backup-opts {{ postgresql_backup_rsync_backup_opts | regex_replace('^-', '\-') | quote }}
   --keep {{ postgresql_backup_keep | quote }}
   {{ '--pg-bin-dir ' ~ __postgresql_pgdg_bin_dir if ansible_os_family == 'RedHat' else '' }}
-  --backup --clean-archive {{ postgresql_backup_dir | quote }}
+  --backup {{ (':' in postgresql_backup_dir) | ternary('', '--clean-archive') }} {{ postgresql_backup_dir | quote }}
 
 postgresql_backup_python_executable: "python"
 

files/backup.py

@@ -30,7 +30,10 @@
 except ImportError:
     from pipes import quote as shlex_quote
 
-import psycopg2
+try:
+    import psycopg2
+except ImportError:
+    psycopg2 = None
 
 
 RSYNC_EXCLUDES = (
@@ -147,6 +150,8 @@ def parse_args(argv):
     parser.add_argument('-v', '--verbose', action='store_true', default=False, help='Verbose output')
     parser.add_argument('backup_path', help='Backup to location (rsync-compatible string)')
     args = parser.parse_args(argv)
+    if args.backup and psycopg2 is None:
+        parser.error('--backup specified but psycopg2 could not be imported')
     if args.clean_archive and ':' in args.backup_path:
         parser.error('--clean-archive cannot be used with remote backup directories')
     return args