Add flag to override URL unreachable state

 - I refactored the Nagios helper a bit to integrate this functionality a bit simpler.
   Before we had distinct methods on the helper that added warn,crit,unko message, now
   there's a general method that takes an int as parameter.
   This way we avoid if-else structures for the new functionality.

check_http_json.py

@@ -69,20 +69,19 @@ def getCode(self):
             code = UNKNOWN_CODE
         return code
 
-    def append_warning(self, warning_message):
-        self.warning_message += warning_message
-
-    def append_critical(self, critical_message):
-        self.critical_message += critical_message
-
-    def append_unknown(self, unknown_message):
-        self.unknown_message += unknown_message
+    def append_message(self, code, msg):
+        if code > 2 or code < 0:
+            self.unknown_message += msg
+        if code == 1:
+            self.warning_message += msg
+        if code == 2:
+            self.critical_message += msg
 
     def append_metrics(self, metrics):
         (performance_data, warning_message, critical_message) = metrics
         self.performance_data += performance_data
-        self.append_warning(warning_message)
-        self.append_critical(critical_message)
+        self.append_message(WARNING_CODE, warning_message)
+        self.append_message(CRITICAL_CODE, critical_message)
 
 
 class JsonHelper:
@@ -444,6 +443,8 @@ def parseArgs(args):
     parser.add_argument('-p', '--path', dest='path', help='Path')
     parser.add_argument('-t', '--timeout', type=int,
                         help='Connection timeout (seconds)')
+    parser.add_argument('--unreachable-state', type=int, default=3,
+                        help='Exit with specified code if URL unreachable. Examples: 1 for Warning, 2 for Critical, 3 for Unknown (default: 3)')
     parser.add_argument('-B', '--basic-auth', dest='auth',
                         help='Basic auth string "username:password"')
     parser.add_argument('-D', '--data', dest='data',
@@ -548,15 +549,15 @@ def prepare_context(args):
             try:
                 context.load_verify_locations(args.cacert)
             except ssl.SSLError:
-                nagios.append_unknown('Error loading SSL CA cert "%s"!' % args.cacert)
+                nagios.append_message(UNKNOWN_CODE, 'Error loading SSL CA cert "%s"!' % args.cacert)
         if args.cert:
             try:
                 context.load_cert_chain(args.cert, keyfile=args.key)
             except ssl.SSLError:
                 if args.key:
-                    nagios.append_unknown('Error loading SSL cert. Make sure key "%s" belongs to cert "%s"!' % (args.key, args.cert))
+                    nagios.append_message(UNKNOWN_CODE, 'Error loading SSL cert. Make sure key "%s" belongs to cert "%s"!' % (args.key, args.cert))
                 else:
-                    nagios.append_unknown('Error loading SSL cert. Make sure "%s" contains the key as well!' % (args.cert))
+                    nagios.append_message(UNKNOWN_CODE, 'Error loading SSL cert. Make sure "%s" contains the key as well!' % (args.cert))
 
     if nagios.getCode() != OK_CODE:
         print(nagios.getMessage())
@@ -630,24 +631,29 @@ def main(cliargs):
         if "json" in e.info().get_content_subtype():
             json_data = e.read()
         else:
-            nagios.append_unknown(" HTTPError[%s], url:%s" % (str(e.code), url))
+            nagios.append_message(UNKNOWN_CODE, " Could not find JSON in HTTP body. HTTPError[%s], url:%s" % (str(e.code), url))
     except URLError as e:
-        nagios.append_critical(" URLError[%s], url:%s" % (str(e.reason), url))
+        # Some users might prefer another exit code if the URL wasn't reached
+        exit_code = args.unreachable_state
+        nagios.append_message(exit_code, " URLError[%s], url:%s" % (str(e.reason), url))
+        # Since we don't got any data, we can simply exit
+        print(nagios.getMessage())
+        sys.exit(nagios.getCode())
 
     try:
         data = json.loads(json_data)
     except ValueError as e:
-        nagios.append_unknown(" Parser error: %s" % str(e))
+        nagios.append_message(UNKNOWN_CODE, " JSON Parser error: %s" % str(e))
 
     else:
         debugPrint(args.debug, 'json:')
         debugPrint(args.debug, data, True)
         # Apply rules to returned JSON data
         processor = JsonRuleProcessor(data, args)
-        nagios.append_warning(processor.checkWarning())
-        nagios.append_critical(processor.checkCritical())
+        nagios.append_message(WARNING_CODE, processor.checkWarning())
+        nagios.append_message(CRITICAL_CODE, processor.checkCritical())
         nagios.append_metrics(processor.checkMetrics())
-        nagios.append_unknown(processor.checkUnknown())
+        nagios.append_message(UNKNOWN_CODE, processor.checkUnknown())
 
     # Print Nagios specific string and exit appropriately
     print(nagios.getMessage())

test/test_check_http_json.py

@@ -84,10 +84,10 @@ def check_data(self, args, jsondata, code):
         data = json.loads(jsondata)
         nagios = NagiosHelper()
         processor = JsonRuleProcessor(data, args)
-        nagios.append_warning(processor.checkWarning())
-        nagios.append_critical(processor.checkCritical())
+        nagios.append_message(WARNING_CODE, processor.checkWarning())
+        nagios.append_message(CRITICAL_CODE, processor.checkCritical())
         nagios.append_metrics(processor.checkMetrics())
-        nagios.append_unknown(processor.checkUnknown())
+        nagios.append_message(UNKNOWN_CODE, processor.checkUnknown())
         self.assertEqual(code, nagios.getCode())
 
     def test_metrics(self):