adding an exception for failures to open role file

ldapcherry/exceptions.py

@@ -9,6 +9,7 @@ class MissingParameter(Exception):
     def __init__(self, section, key):
         self.section = section
         self.key = key
+        self.log = "missing parameter <%(key)s> in section <%(section)s>" % { 'key' : key, 'section' : section }
 
 class MissingKey(Exception):
     def __init__(self, key):
@@ -17,8 +18,17 @@ class MissingKey(Exception):
 class DumplicateRoleKey(Exception):
     def __init__(self, role):
         self.role = role
+        self.log = "duplicate role key <%(role)s> in role file" % { 'role' : role}
 
 class DumplicateRoleContent(Exception):
     def __init__(self, role1, role2):
         self.role1 = role1
         self.role2 = role2
+        self.log = "role <%(role1)s> and <%(role2)s> are identical" % { 'role1' : role1, 'role2': role2}
+
+class MissingRolesFile(Exception):
+    def __init__(self, rolefile):
+        self.rolefile = rolefile
+        self.log = "fail to open role file <%(rolefile)s>" % { 'rolefile' : rolefile}
+
+

ldapcherry/roles.py

@@ -10,13 +10,16 @@ import sys
 
 from ldapcherry.pyyamlwrapper import loadNoDump
 from ldapcherry.pyyamlwrapper import DumplicatedKey
-from ldapcherry.exceptions import DumplicateRoleKey, MissingKey, DumplicateRoleContent
+from ldapcherry.exceptions import DumplicateRoleKey, MissingKey, DumplicateRoleContent, MissingRolesFile
 
 
 class Roles:
 
     def __init__(self, role_file):
+        try:
             stream = open(role_file, 'r')
+        except:
+            raise MissingRolesFile(role_file)
         try:
             self.roles_raw = loadNoDump(stream)
         except DumplicatedKey as e:

tests/test_Roles.py

@@ -7,7 +7,7 @@ from __future__ import unicode_literals
 import pytest
 import sys
 from ldapcherry.roles import Roles
-from ldapcherry.exceptions import DumplicateRoleKey, MissingKey, DumplicateRoleContent
+from ldapcherry.exceptions import DumplicateRoleKey, MissingKey, DumplicateRoleContent, MissingRolesFile
 from ldapcherry.pyyamlwrapper import DumplicatedKey, RelationError
 
 
@@ -34,6 +34,15 @@ class TestError(object):
         else:
             raise AssertionError("expected an exception")
 
+
+    def testNoFile(self):
+        try:
+            inv = Roles('./tests/cfg/dontexist')
+        except MissingRolesFile:
+            return
+        else:
+            raise AssertionError("expected an exception")
+
     def testRoleContentDuplication(self):
         try:
             inv = Roles('./tests/cfg/roles_content_dump.yml')