BUGFIX: fix c931d60c

After c931d60c, default options were changed and we didn't want that.

Rewrite the code so that we have a clearer scheme:
 * all options of format are listed as FormatConfig attributes with default values
 * all values present in configuration file (.cfg) erase the previous options
 * all values present in command line erase the previous options

We use the special default argparse.SUPPRESS that removes totally the arg from arg dict so that only PRESENT options erase something

slapos/cli/format.py

@@ -29,6 +29,7 @@
 
 import logging
 import sys
+import argparse
 
 from slapos.cli.command import check_root_user
 from slapos.cli.config import ConfigCommand
@@ -45,41 +46,45 @@ class FormatCommand(ConfigCommand):
         ap = super(FormatCommand, self).get_parser(prog_name)
 
         ap.add_argument('-x', '--computer_xml',
+                        default=argparse.SUPPRESS, #can't use default here because it would overwrite .cfg
                         help="Path to file with computer's XML. If does not exists, will be created")
 
         ap.add_argument('--computer_json',
+                        default=argparse.SUPPRESS, #can't use default here because it would overwrite .cfg
                         help="Path to a JSON version of the computer's XML (for development only)")
 
         ap.add_argument('-i', '--input_definition_file',
+                        default=argparse.SUPPRESS, #can't use default here because it would overwrite .cfg
                         help="Path to file to read definition of computer instead of "
                         "declaration. Using definition file allows to disable "
                         "'discovery' of machine services and allows to define computer "
                         "configuration in fully controlled manner.")
 
         ap.add_argument('-o', '--output_definition_file',
+                        default=argparse.SUPPRESS, #can't use default here because it would overwrite .cfg
                         help="Path to file to write definition of computer from "
                         "declaration.")
 
         ap.add_argument('--alter_user',
                         choices=['True', 'False'],
-                        #default=FormatConfig.alter_user, #can't use default here because it would overwrite .cfg
+                        default=argparse.SUPPRESS, #can't use default here because it would overwrite .cfg
                         help='Shall slapformat alter user database'
                              ' (default: {})'.format(FormatConfig.alter_user))
 
         ap.add_argument('--alter_network',
                         choices=['True', 'False'],
-                        #default=FormatConfig.alter_network, #can't use default here because it would overwrite .cfg
+                        default=argparse.SUPPRESS, #can't use default here because it would overwrite .cfg
                         help='Shall slapformat alter network configuration'
                              ' (default: {})'.format(FormatConfig.alter_network))
 
         ap.add_argument('--now',
-                        default=False,
+                        default=False, # can have a default as it is not in .cfg
                         action="store_true",
                         help='Launch slapformat without delay'
                              ' (default: %(default)s)')
 
         ap.add_argument('-n', '--dry_run',
-                        default=False,
+                        default=False, # can have a default as it is not in .cfg
                         action="store_true",
                         help="Don't actually do anything"
                              " (default: %(default)s)")

slapos/format.py

@@ -1376,22 +1376,38 @@ def do_format(conf):
 
 
 class FormatConfig(object):
-  key_file = None
-  cert_file = None
-  alter_network = 'True'
-  alter_user = 'True'
+  """This class represents the options for slapos node format
+  all the attributes of this class are options
+  all the attributes can be modified by config file (.cfg)
+  some attributes can be modified by command line"""
+
+  # Network options
+  alter_network = 'True' # modifiable by cmdline
+  interface_name = None
+  ipv6_interface = None
   create_tap = True
   create_tun = False
-  computer_xml = None
-  computer_json = None
-  input_definition_file = None
-  log_file = None
-  output_definition_file = None
-  dry_run = None
-  software_user = 'slapsoft'
+  tap_base_name = None
+  ipv4_local_network = None
   tap_gateway_interface = ''
   use_unique_local_address_block = False
+
+  # User options
+  alter_user = 'True' # modifiable by cmdline
+  software_user = 'slapsoft'
   instance_storage_home = None
+  partition_base_name = None
+  user_base_name = None
+
+  # Other options
+  input_definition_file = None  # modifiable by cmdline
+  computer_xml = None           # modifiable by cmdline
+  computer_json = None          # modifiable by cmdline
+  log_file = None               # modifiable by cmdline
+  output_definition_file = None # modifiable by cmdline
+  dry_run = None                # modifiable by cmdline
+  key_file = None
+  cert_file = None
 
   def __init__(self, logger):
     self.logger = logger
@@ -1414,30 +1430,20 @@ class FormatConfig(object):
 
   def mergeConfig(self, args, configp):
     """
-    Set options given by parameters.
+    Set options given by config files and arguments.
     Must be executed before setting up the logger.
     """
-    self.key_file = None
-    self.cert_file = None
-
-    # Set argument parameters
-    for key, value in args.__dict__.items():
-      setattr(self, key, value)
-
-    # Merges the arguments and configuration
+    # First, the configuration file options erase the default class options
     for section in ("slapformat", "slapos"):
       configuration_dict = dict(configp.items(section))
       for key in configuration_dict:
-        if not getattr(self, key, None):
         setattr(self, key, configuration_dict[key])
 
-  def setConfig(self):
-    # setup some nones
-    for parameter in ['interface_name', 'partition_base_name', 'user_base_name',
-          'tap_base_name', 'ipv4_local_network', 'ipv6_interface']:
-      if getattr(self, parameter, None) is None:
-        setattr(self, parameter, None)
+    # Second, the command line arguments erase the configuration file options
+    for key, value in args.__dict__.items():
+      setattr(self, key, value)
 
+  def setConfig(self):
     # deprecated options raise an error
     for option in ['bridge_name', 'no_bridge']:
       if getattr(self, option, None):