Merge pull request #7 from mark-burnett/common-janitor-code

Add common code for script construction

ptero_common/janitors/__init__.py

@@ -0,0 +1,72 @@
+import argparse
+import logging
+import os
+import sys
+
+
+__all__ = ['perform_cleanup']
+
+
+LOG = logging.getLogger(__name__)
+
+
+def perform_cleanup(janitor_factory=None, required_envvars=None):
+    init()
+    validate_perform_cleanup_args(janitor_factory, required_envvars)
+
+    try:
+        janitors = janitor_factory()
+    except:
+        LOG.exception('Failed to construct all janitors')
+        sys.exit(1)
+
+    for janitor in janitors:
+        try:
+            janitor.clean()
+        except:
+            LOG.exception('Janitor %s failed to cleanup', janitor)
+            sys.exit(1)
+
+
+def validate_allowed(force):
+    if (not force) and not os.environ.get('PTERO_ALLOW_JANITORS'):
+        LOG.error('PTERO_ALLOW_JANITORS not set, and --force not given')
+        sys.exit(1)
+
+
+def validate_environment(required_envvar_names):
+    errors = []
+    for varname in required_envvar_names:
+        if varname not in os.environ:
+            errors.append('%s is not set' % varname)
+
+    if errors:
+        for error in sorted(errors):
+            LOG.error('%s', error)
+        sys.exit(1)
+
+
+def parse_args():
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument('--force', action='store_true', default=False,
+                        help='Purge regardless of PTERO_ALLOW_JANITORS')
+
+    parser.add_argument('--log-level', dest='log_level', default='WARN')
+
+    return parser.parse_args()
+
+
+def init():
+    args = parse_args()
+    logging.basicConfig(level=args.log_level)
+    validate_allowed(args.force)
+
+
+def validate_perform_cleanup_args(janitor_factory, required_envvars):
+    if required_envvars:
+        validate_environment(required_envvars)
+
+    if not callable(janitor_factory):
+        LOG.error('janitor_factory must be callable')
+        sys.exit(1)