Adding signal handler module

Signal handler function is added for graceful exiting of
the test framework.

Fixes: #208
Signed-off-by: Nishith Vihar Sakinala <nsakinal@redhat.com>

core/environ.py

@@ -1,6 +1,8 @@
 import sys
 sys.path.insert(1, ".")
 from common.mixin import RedantMixin
+from signal_handler import signal_handler
+import signal
 
 class environ:
     """

core/parsing/params_handler.py

@@ -3,15 +3,18 @@
 which contains APIs for configuration parameter
 parsing.
 """
+import sys
 from parsing.test_parser import Parser
+from core.signal_handler import signal_handler
+import signal
 
 
 class ParamsHandler:
     """
     This class contains all the APIs required for fetching
     the values of all the configuration parameters.
     """
-
+    
     @classmethod
     def set_config_hashmap(cls, filepath: str):
         """

core/parsing/test_parser.py

@@ -2,7 +2,11 @@
 This module consists a single class - Parser,which
 parses the configuration file given the filepath.
 """
+import sys
 import yaml
+sys.path.insert(1,".")
+from core.signal_handler import signal_handler
+import signal
 
 
 class Parser():

core/redant_main.py

@@ -14,6 +14,8 @@
 from test_runner import TestRunner
 from result_handler import ResultHandler
 from environ import environ
+from signal_handler import signal_handler
+import signal
 
 def pars_args():
     """
@@ -58,7 +60,7 @@ def main():
 
     start = time.time()
     args = pars_args()
-
+    
     ParamsHandler.set_config_hashmap(args.config_file)
 
     # Obtain the client and server dict.
@@ -97,4 +99,8 @@ def main():
 
 
 if __name__ == '__main__':
+
+    signal.signal(signal.SIGINT, signal_handler)
+    signal.signal(signal.SIGTSTP, signal_handler)
+
     main()

core/result_handler.py

@@ -7,6 +7,8 @@
 """
 from prettytable import PrettyTable
 from colorama import Fore, Style
+from signal_handler import signal_handler
+import signal
 
 
 class ResultHandler:

core/signal_handler.py

@@ -0,0 +1,20 @@
+"""
+This file consists of functions for handling 
+signals. Signal handling is required for the
+graceful exit of the test framework
+"""
+
+import signal
+
+def signal_handler(signalNumber, frame):
+    """
+    Function for handling signal and raising the
+    SystemExit call for graceful exit of the test 
+    framework
+    Args:
+        signalNumber (int): The signal number of the signal caught
+        frame: current stack frame, None or stack frame object.  
+    """
+    print("Signal Received",signalNumber)
+    raise SystemExit('Exiting...')
+    return

core/test_list_builder.py

@@ -13,6 +13,8 @@
 import copy
 import sys
 from comment_parser.comment_parser import extract_comments
+from signal_handler import signal_handler
+import signal
 
 
 class TestListBuilder:

core/test_runner.py

@@ -8,7 +8,8 @@
 from threading import Thread, Semaphore
 from colorama import Fore, Style
 from runner_thread import RunnerThread
-
+from signal_handler import signal_handler
+import signal
 
 class TestRunner:
     """

tools/signal_handler.py

@@ -0,0 +1,21 @@
+"""
+This file contains a class named SignalHandler
+which contains different signal handler methods
+for different signals. Signal Handling is required
+for the graceful exiting of the test framework.
+"""
+
+import signal
+
+def signal_handler(signalNumber, frame):
+        """
+        Function catches the signal given and raises SystemExit
+        call to exit the framework gracefully
+        Args:
+            signalNumber: The signal number of the signal caught according
+                          to POSIX standard
+            frame: current stack frame, either None or frame object
+        """
+        print("Signal Received",signalNumber)
+        raise SystemExit('Exiting...')
+        return