ROHD-2105: Use Python's configparser to extract credentials

stager_access.py

@@ -25,7 +25,8 @@
 __version__ = "1.5"
 
 import datetime
-from os.path import expanduser
+import configparser
+from os.path import expanduser, exists
 
 
 # Python2/3 dependent stuff
@@ -38,32 +39,51 @@ else:
     import xmlrpclib
     string_types = basestring
 
+
+def parse_config_file(file):
+    """ Parse an ini file that shall contain user credentials
+        for the LOFAR stager API.
+    """
+    if exists(file) is False:
+        # File not found, nothing to do.
+        raise Exception
+    with open(file, 'r') as stream:
+        print("%s - stager_access: Parsing user credentials found in file \"%s\"." % (datetime.datetime.now(), file))
+        config = configparser.ConfigParser()
+        # This may seem odd but the Python configparser cannot parse ini
+        # files that just contain "A = B" lines without a section name
+        # like "[Foo Bar]".  So I just add a section name just before the
+        # config file is read.
+        config.read_string("[LOFAR stager credentials]\n" + stream.read())
+    return config["LOFAR stager credentials"]
+
 #---
+
 # Determine credentials and create proxy
 user = None
 passw = None
-try:
-    f = expanduser("~/.awe/Environment.cfg")
-    with open(f,'r') as file:
-        print("%s - stager_access: Parsing user credentials from \"%s\"" % (datetime.datetime.now(), f))
-        for line in file:
-            if line.startswith("database_user"):
-                user = line.split(':')[1].strip()
-            if line.startswith("database_password"):
-                passw = line.split(':')[1].strip()
-except IOError:
-    f = expanduser("~/.stagingrc")
-    with open(f,'r') as file:
-        print("%s - stager_access: Parsing user credentials from \"%s\"" % (datetime.datetime.now(), f))
-        for line in file:
-            if line.startswith("user"):
-                user = line.split('=')[1].strip()
-            if line.startswith("password"):
-                passw = line.split('=', 1)[1].strip()
-
-print("%s - stager_access: Creating proxy" % (datetime.datetime.now()))
-proxy = xmlrpclib.ServerProxy("https://"+user+':'+passw+"@webportal.astron.nl/service-public/xmlrpc")
-LtaStager =  proxy.LtaStager
+
+# Iterate over possible files that could contain user credentials.
+for f in ["~/.awe/Environment.cfg", "~/.stagingrc"]:
+    file = expanduser(f)
+    credentials = []
+    try:
+        credentials = parse_config_file(file)
+    except Exception:
+        print("%s - stager_access: Could not find user credential file \"%s\"." % (datetime.datetime.now(), file))
+        continue
+
+    user = credentials["user"]
+    passw = credentials["password"]
+    break
+
+if user is not None and passw is not None:
+    print("%s - stager_access: Creating proxy" % (datetime.datetime.now()))
+    proxy = xmlrpclib.ServerProxy("https://"+user+':'+passw+"@webportal.astron.nl/service-public/xmlrpc")
+    LtaStager =  proxy.LtaStager
+else:
+    print("%s - stager_access:  Could not find a file with user credentials." % (datetime.datetime.now()))
+
 
 # ---