SW-415: automatically create dbcredentials file with sane defaults when no...

SW-415: automatically create dbcredentials file with sane defaults when no credentials are found. added tests.

LCS/PyCommon/dbcredentials.py

@@ -131,7 +131,7 @@ class Credentials:
 
 class DBCredentials:
   def __init__(self, filepatterns=None):
-    self.filepatterns = filepatterns if filepatterns else [
+    self.filepatterns = filepatterns if filepatterns is not None else [
       "{LOFARROOT}/etc/dbcredentials/*.ini",
       "{HOME}/.lofar/dbcredentials/*.ini",
     ]
@@ -182,13 +182,17 @@ class DBCredentials:
     creates a dbcredentials file with defaults in ~/.lofar/dbcredentials/<database>.ini
     :param database: name of the database/file
     """
-    new_path = os.path.join(user_info.pw_dir, '.lofar', 'dbcredentials', database+'.ini')
-    if not os.path.exists(os.path.dirname(new_path)):
-      os.makedirs(os.path.dirname(new_path))
-    with open(new_path, 'w') as new_file:
-      new_file.write("[database:%s]\nhost=localhost\nuser=%s\npassword=unknown\ntype=unknown\nport=0\ndatabase=%s"
-                     % (database,user_info.pw_name,database))
-    logger.info("created default dbcredentials file for database=%s at %s", database, new_path)
+    extensions = list(set(os.path.splitext(pat)[1] for pat in self.filepatterns))
+    if extensions:
+      #pick first extension
+      extension = extensions[0]
+      new_path = os.path.join(user_info.pw_dir, '.lofar', 'dbcredentials', database+extension)
+      if not os.path.exists(os.path.dirname(new_path)):
+        os.makedirs(os.path.dirname(new_path))
+      with open(new_path, 'w') as new_file:
+        new_file.write("[database:%s]\nhost=localhost\nuser=%s\npassword=unknown\ntype=unknown\nport=0\ndatabase=%s"
+                       % (database,user_info.pw_name,database))
+      logger.info("created default dbcredentials file for database=%s at %s", database, new_path)
 
   def get(self, database):
     """

LCS/PyCommon/test/t_dbcredentials.py

 #!/usr/bin/env python
 
+import os
 import unittest
 import tempfile
+from uuid import uuid4
 from lofar.common.dbcredentials import *
+try:
+  #python2
+  from ConfigParser import NoSectionError
+except ImportError:
+  #python3
+  from configparser import NoSectionError
 
 def setUpModule():
   pass
@@ -53,8 +61,21 @@ class TestDBCredentials(unittest.TestCase):
   def test_get_non_existing(self):
     dbc = DBCredentials(filepatterns=[])
 
-    with self.assertRaises(DBCredentials.NoSectionError):
-      dbc.get("UNKNOWN")
+    non_existing_db_name = "UNKNOWN-%s" % (uuid4(),)
+    with self.assertRaises(NoSectionError):
+      dbc.get(non_existing_db_name)
+
+  def test_creation_for_non_existing(self):
+    dbc = DBCredentials(filepatterns=["{HOME}/.lofar/dbcredentials/*.test_extension"])
+
+    non_existing_db_name = "UNKNOWN-%s" % (uuid4(),)
+    creds = dbc.get(non_existing_db_name)
+    self.assertTrue(creds)
+    self.assertEqual(non_existing_db_name, creds.database)
+
+    expected_path = os.path.expanduser("~/.lofar/dbcredentials/%s.test_extension" % (non_existing_db_name,))
+    self.assertTrue(os.path.exists(expected_path))
+    os.remove(expected_path)
 
   def test_list(self):
     dbc = DBCredentials(filepatterns=[])