fix ensure --extra-args is string and not None, if None it adds None word in the cmdline and breaks the commands

Author: pablodav

curlnagios/__main__.py

@@ -40,7 +40,7 @@ def parse_args(args):
 
     parser.add_argument('-u', '--url', dest='url', nargs='?', default=None, const=None,
                         help='url to check \n')
-    parser.add_argument('-e', '--extra_args', dest='extra_args', nargs='?', default=None, const=None,
+    parser.add_argument('-e', '--extra_args', dest='extra_args', nargs='?', default='', const=None,
                             help='extra args to add to curl, see curl manpage  \n')
 
     # Arguments to check using OAuth2

curlnagios/plugin_check.py

@@ -4,7 +4,7 @@
 import subprocess
 
 class curlCheck:
-    def __init__(self, URL, extra_args, auth_args=''):
+    def __init__(self, URL, extra_args='', auth_args=''):
         """
         :param URL: provide url to get/put data.
         :param extra_args: any argument for curl command
@@ -36,7 +36,7 @@ def collect_data(self):
         """
         ### some code here
         ### or calling external modules
-        cmdline = "curl {} {} --fail -s -o /dev/null {} -w \\ {}".format(self.url, self.auth_args, self.extra_args, self.std_args)
+        cmdline = "curl {} --fail -s -o /dev/null {} -w \\ {}  {}".format(self.url, self.extra_args, self.std_args, self.auth_args)
 
         retrcode, retroutput = subprocess.getstatusoutput(cmdline)
         jsonoutput = json.loads(retroutput)