Improve ug_util.py (#1013)

No functional changes.

1 files changed, 91 insertions, 143 deletions

diff --git a/cloudinit/distros/ug_util.py b/cloudinit/distros/ug_util.py
index 08446a95..600b743f 100755
--- a/cloudinit/distros/ug_util.py
+++ b/cloudinit/distros/ug_util.py
@@ -16,77 +16,59 @@ from cloudinit import util
 LOG = logging.getLogger(__name__)
 
 
-# Normalizes a input group configuration
-# which can be a comma seperated list of
-# group names, or a list of group names
-# or a python dictionary of group names
-# to a list of members of that group.
+# Normalizes an input group configuration which can be:
+# Comma seperated string or a list or a dictionary
 #
-# The output is a dictionary of group
-# names => members of that group which
-# is the standard form used in the rest
-# of cloud-init
+# Returns dictionary of group names => members of that group which is the
+# standard form used in the rest of cloud-init
 def _normalize_groups(grp_cfg):
     if isinstance(grp_cfg, str):
-        grp_cfg = grp_cfg.strip().split(",")
+        grp_cfg = grp_cfg.strip().split(',')
+
     if isinstance(grp_cfg, list):
         c_grp_cfg = {}
         for i in grp_cfg:
             if isinstance(i, dict):
                 for k, v in i.items():
-                    if k not in c_grp_cfg:
-                        if isinstance(v, list):
-                            c_grp_cfg[k] = list(v)
-                        elif isinstance(v, str):
-                            c_grp_cfg[k] = [v]
-                        else:
-                            raise TypeError("Bad group member type %s" %
-                                            type_utils.obj_name(v))
+                    if not isinstance(v, (list, str)):
+                        raise TypeError('Bad group member type %s'
+                                        % (type_utils.obj_name(v)))
+
+                    if isinstance(v, list):
+                        c_grp_cfg.setdefault(k, []).extend(v)
                     else:
-                        if isinstance(v, list):
-                            c_grp_cfg[k].extend(v)
-                        elif isinstance(v, str):
-                            c_grp_cfg[k].append(v)
-                        else:
-                            raise TypeError("Bad group member type %s" %
-                                            type_utils.obj_name(v))
+                        c_grp_cfg.setdefault(k, []).append(v)
             elif isinstance(i, str):
                 if i not in c_grp_cfg:
                     c_grp_cfg[i] = []
             else:
-                raise TypeError("Unknown group name type %s" %
-                                type_utils.obj_name(i))
+                raise TypeError('Unknown group name type %s'
+                                % (type_utils.obj_name(i)))
         grp_cfg = c_grp_cfg
+
     groups = {}
     if isinstance(grp_cfg, dict):
-        for (grp_name, grp_members) in grp_cfg.items():
+        for grp_name, grp_members in grp_cfg.items():
             groups[grp_name] = util.uniq_merge_sorted(grp_members)
     else:
-        raise TypeError(("Group config must be list, dict "
-                         " or string types only and not %s") %
-                        type_utils.obj_name(grp_cfg))
+        raise TypeError(('Group config must be list, dict or string type only '
+                         'but found %s') % (type_utils.obj_name(grp_cfg)))
     return groups
 
 
-# Normalizes a input group configuration
-# which can be a comma seperated list of
-# user names, or a list of string user names
-# or a list of dictionaries with components
-# that define the user config + 'name' (if
-# a 'name' field does not exist then the
-# default user is assumed to 'own' that
-# configuration.
+# Normalizes an input group configuration which can be: a list or a dictionary
 #
-# The output is a dictionary of user
-# names => user config which is the standard
-# form used in the rest of cloud-init. Note
-# the default user will have a special config
-# entry 'default' which will be marked as true
-# all other users will be marked as false.
+# components that define the user config + 'name' (if a 'name' field does not
+# exist then the default user is assumed to 'own' that configuration.)
+#
+# Returns a dictionary of user names => user config which is the standard form
+# used in the rest of cloud-init. Note the default user will have a special
+# config entry 'default' which will be marked true and all other users will be
+# marked false.
 def _normalize_users(u_cfg, def_user_cfg=None):
     if isinstance(u_cfg, dict):
         ad_ucfg = []
-        for (k, v) in u_cfg.items():
+        for k, v in u_cfg.items():
             if isinstance(v, (bool, int, float, str)):
                 if util.is_true(v):
                     ad_ucfg.append(str(k))
@@ -94,8 +76,8 @@ def _normalize_users(u_cfg, def_user_cfg=None):
                 v['name'] = k
                 ad_ucfg.append(v)
             else:
-                raise TypeError(("Unmappable user value type %s"
-                                 " for key %s") % (type_utils.obj_name(v), k))
+                raise TypeError(('Unmappable user value type %s for key %s')
+                                % (type_utils.obj_name(v), k))
         u_cfg = ad_ucfg
     elif isinstance(u_cfg, str):
         u_cfg = util.uniq_merge_sorted(u_cfg)
@@ -107,181 +89,147 @@ def _normalize_users(u_cfg, def_user_cfg=None):
                 if u and u not in users:
                     users[u] = {}
         elif isinstance(user_config, dict):
-            if 'name' in user_config:
-                n = user_config.pop('name')
-                prev_config = users.get(n) or {}
-                users[n] = util.mergemanydict([prev_config,
-                                               user_config])
-            else:
-                # Assume the default user then
-                prev_config = users.get('default') or {}
-                users['default'] = util.mergemanydict([prev_config,
-                                                       user_config])
+            n = user_config.pop('name', 'default')
+            prev_config = users.get(n) or {}
+            users[n] = util.mergemanydict([prev_config, user_config])
         else:
-            raise TypeError(("User config must be dictionary/list "
-                             " or string types only and not %s") %
-                            type_utils.obj_name(user_config))
+            raise TypeError(('User config must be dictionary/list or string '
+                             ' types only and not %s')
+                            % (type_utils.obj_name(user_config)))
 
     # Ensure user options are in the right python friendly format
     if users:
         c_users = {}
-        for (uname, uconfig) in users.items():
+        for uname, uconfig in users.items():
             c_uconfig = {}
-            for (k, v) in uconfig.items():
+            for k, v in uconfig.items():
                 k = k.replace('-', '_').strip()
                 if k:
                     c_uconfig[k] = v
             c_users[uname] = c_uconfig
         users = c_users
 
-    # Fixup the default user into the real
-    # default user name and replace it...
+    # Fix the default user into the actual default user name and replace it.
     def_user = None
     if users and 'default' in users:
         def_config = users.pop('default')
         if def_user_cfg:
-            # Pickup what the default 'real name' is
-            # and any groups that are provided by the
-            # default config
+            # Pickup what the default 'real name' is and any groups that are
+            # provided by the default config
             def_user_cfg = def_user_cfg.copy()
             def_user = def_user_cfg.pop('name')
             def_groups = def_user_cfg.pop('groups', [])
-            # Pickup any config + groups for that user name
-            # that we may have previously extracted
+            # Pick any config + groups for the user name that we may have
+            # extracted previously
             parsed_config = users.pop(def_user, {})
             parsed_groups = parsed_config.get('groups', [])
-            # Now merge our extracted groups with
-            # anything the default config provided
+            # Now merge the extracted groups with the default config provided
             users_groups = util.uniq_merge_sorted(parsed_groups, def_groups)
-            parsed_config['groups'] = ",".join(users_groups)
-            # The real config for the default user is the
-            # combination of the default user config provided
-            # by the distro, the default user config provided
-            # by the above merging for the user 'default' and
-            # then the parsed config from the user's 'real name'
-            # which does not have to be 'default' (but could be)
-            users[def_user] = util.mergemanydict([def_user_cfg,
-                                                  def_config,
+            parsed_config['groups'] = ','.join(users_groups)
+            # The real config for the default user is the combination of the
+            # default user config provided by the distro, the default user
+            # config provided by the above merging for the user 'default' and
+            # then the parsed config from the user's 'real name' which does not
+            # have to be 'default' (but could be)
+            users[def_user] = util.mergemanydict([def_user_cfg, def_config,
                                                   parsed_config])
 
-    # Ensure that only the default user that we
-    # found (if any) is actually marked as being
-    # the default user
-    if users:
-        for (uname, uconfig) in users.items():
-            if def_user and uname == def_user:
-                uconfig['default'] = True
-            else:
-                uconfig['default'] = False
+    # Ensure that only the default user that we found (if any) is actually
+    # marked as the default user
+    for uname, uconfig in users.items():
+        uconfig['default'] = (uname == def_user if def_user else False)
 
     return users
 
 
-# Normalizes a set of user/users and group
-# dictionary configuration into a useable
-# format that the rest of cloud-init can
-# understand using the default user
-# provided by the input distrobution (if any)
-# to allow for mapping of the 'default' user.
+# Normalizes a set of user/users and group dictionary configuration into an
+# usable format so that the rest of cloud-init can understand using the default
+# user provided by the input distribution (if any) to allow mapping of the
+# 'default' user.
 #
 # Output is a dictionary of group names -> [member] (list)
 # and a dictionary of user names -> user configuration (dict)
 #
-# If 'user' exists it will override
-# the 'users'[0] entry (if a list) otherwise it will
-# just become an entry in the returned dictionary (no override)
+# If 'user' exists, it will override
+# The 'users'[0] entry (if a list) otherwise it will just become an entry in
+# the returned dictionary (no override)
 def normalize_users_groups(cfg, distro):
     if not cfg:
         cfg = {}
 
-    users = {}
-    groups = {}
-    if 'groups' in cfg:
-        groups = _normalize_groups(cfg['groups'])
-
     # Handle the previous style of doing this where the first user
     # overrides the concept of the default user if provided in the user: XYZ
     # format.
     old_user = {}
     if 'user' in cfg and cfg['user']:
         old_user = cfg['user']
-        # Translate it into the format that is more useful
-        # going forward
+        # Translate it into a format that will be more useful going forward
         if isinstance(old_user, str):
-            old_user = {
-                'name': old_user,
-            }
-        if not isinstance(old_user, dict):
+            old_user = {'name': old_user}
+        elif not isinstance(old_user, dict):
             LOG.warning(("Format for 'user' key must be a string or dictionary"
                          " and not %s"), type_utils.obj_name(old_user))
             old_user = {}
 
-    # If no old user format, then assume the distro
-    # provides what the 'default' user maps to, but notice
-    # that if this is provided, we won't automatically inject
-    # a 'default' user into the users list, while if a old user
-    # format is provided we will.
+    # If no old user format, then assume the distro provides what the 'default'
+    # user maps to, but notice that if this is provided, we won't automatically
+    # inject a 'default' user into the users list, while if an old user format
+    # is provided we will.
     distro_user_config = {}
     try:
         distro_user_config = distro.get_default_user()
     except NotImplementedError:
-        LOG.warning(("Distro has not implemented default user "
-                     "access. No distribution provided default user"
-                     " will be normalized."))
+        LOG.warning(('Distro has not implemented default user access. No '
+                     'distribution provided default user will be normalized.'))
 
-    # Merge the old user (which may just be an empty dict when not
-    # present with the distro provided default user configuration so
-    # that the old user style picks up all the distribution specific
-    # attributes (if any)
+    # Merge the old user (which may just be an empty dict when not present)
+    # with the distro provided default user configuration so that the old user
+    # style picks up all the distribution specific attributes (if any)
     default_user_config = util.mergemanydict([old_user, distro_user_config])
 
     base_users = cfg.get('users', [])
     if not isinstance(base_users, (list, dict, str)):
         LOG.warning(("Format for 'users' key must be a comma separated string"
-                     " or a dictionary or a list and not %s"),
+                     " or a dictionary or a list but found %s"),
                     type_utils.obj_name(base_users))
         base_users = []
 
     if old_user:
-        # Ensure that when user: is provided that this user
-        # always gets added (as the default user)
+        # When 'user:' is provided, it should be made as the default user
         if isinstance(base_users, list):
-            # Just add it on at the end...
             base_users.append({'name': 'default'})
         elif isinstance(base_users, dict):
             base_users['default'] = dict(base_users).get('default', True)
         elif isinstance(base_users, str):
-            # Just append it on to be re-parsed later
-            base_users += ",default"
+            base_users += ',default'
+
+    groups = {}
+    if 'groups' in cfg:
+        groups = _normalize_groups(cfg['groups'])
 
     users = _normalize_users(base_users, default_user_config)
     return (users, groups)
 
 
-# Given a user dictionary config it will
-# extract the default user name and user config
-# from that list and return that tuple or
-# return (None, None) if no default user is
-# found in the given input
+# Given a user dictionary config, extract the default user name and user config
+# and return them or return (None, None) if no default user is found
 def extract_default(users, default_name=None, default_config=None):
     if not users:
-        users = {}
+        return (default_name, default_config)
 
     def safe_find(entry):
         config = entry[1]
         if not config or 'default' not in config:
             return False
-        else:
-            return config['default']
+        return config['default']
 
-    tmp_users = users.items()
-    tmp_users = dict(filter(safe_find, tmp_users))
+    tmp_users = dict(filter(safe_find, users.items()))
     if not tmp_users:
         return (default_name, default_config)
-    else:
-        name = list(tmp_users)[0]
-        config = tmp_users[name]
-        config.pop('default', None)
-        return (name, config)
+
+    name = list(tmp_users)[0]
+    config = tmp_users[name]
+    config.pop('default', None)
+    return (name, config)
 
 # vi: ts=4 expandtab