CI: Improve error handling in Iperf3 JSON analysis functions

Handle exception when error occurs during the iperf3 JSON log opening and decoding.

Prevent errors observed in these runs:

• https://jenkins-oai.eurecom.fr/job/RAN-SA-B200-Module-SABOX-Container/5268/
• https://jenkins-oai.eurecom.fr/job/RAN-Container-Parent/9533/

ci-scripts/cls_oaicitest.py

@@ -95,25 +95,26 @@ def Iperf_ComputeTime(args):
 		raise Exception('Iperf time not found!')
 	return int(result.group('iperf_time'))
 
-def Iperf_analyzeV3TCPJson(filename, iperf_tcp_rate_target):
+def get_JSON(filename):
 	try:
 		with open(filename) as file:
-			filename = json.load(file)
-	except FileNotFoundError:
-		return (False, 'JSON log file not present')
-	except json.JSONDecodeError:
+			json_file = json.load(file)
+	except FileNotFoundError as e:
+		return (False, f'JSON log file not found: {e}')
+	except json.JSONDecodeError as e:
 		if (os.path.getsize(filename)==0):
 			return (False, 'JSON log file is empty')
-		return (False, 'Could not decode JSON log file')
+		return (False, f'Could not decode JSON log file: {e}')
 	except Exception as e:
-		return (False, f'Unexpected error: {str(e)}')
+		return (False, f'Unexpected error: {e}')
+	return (True, json_file)
 
+def Iperf_analyzeV3TCPJson(filename, iperf_tcp_rate_target):
 	try:
 		sender_bitrate   = round(filename['end']['streams'][0]['sender']['bits_per_second']/1000000,2)
 		receiver_bitrate = round(filename['end']['streams'][0]['receiver']['bits_per_second']/1000000,2)
 	except Exception as e:
-		return (False, 'Could not compute Iperf3 bitrate!')
-
+		return (False, f'Could not compute Iperf3 bitrate: {e}')
 	snd_msg = f'Sender Bitrate   : {sender_bitrate} Mbps'
 	rcv_msg = f'Receiver Bitrate : {receiver_bitrate} Mbps'
 	success = True
@@ -126,26 +127,13 @@ def Iperf_analyzeV3TCPJson(filename, iperf_tcp_rate_target):
 	return(success, f'{snd_msg}\n{rcv_msg}')
 
 def Iperf_analyzeV3BIDIRJson(filename):
-	try:
-		with open(filename) as file:
-			filename = json.load(file)
-	except FileNotFoundError:
-		return (False, 'JSON log file not present')
-	except json.JSONDecodeError:
-		if (os.path.getsize(filename)==0):
-			return (False, 'JSON log file is empty')
-		return (False, 'Could not decode JSON log file')
-	except Exception as e:
-		return (False, f'Unexpected error: {str(e)}')
-
 	try:
 		sender_bitrate_ul   = round(filename['end']['streams'][0]['sender']['bits_per_second']/1000000,2)
 		receiver_bitrate_ul = round(filename['end']['streams'][0]['receiver']['bits_per_second']/1000000,2)
 		sender_bitrate_dl   = round(filename['end']['streams'][1]['sender']['bits_per_second']/1000000,2)
 		receiver_bitrate_dl = round(filename['end']['streams'][1]['receiver']['bits_per_second']/1000000,2)
 	except Exception as e:
-		return (False, 'Could not compute BIDIR bitrate!')
-
+		return (False, f'Could not compute BIDIR bitrate: {e}')
 	msg = f'Sender Bitrate DL   : {sender_bitrate_dl} Mbps\n'
 	msg += f'Receiver Bitrate DL : {receiver_bitrate_dl} Mbps\n'
 	msg += f'Sender Bitrate UL   : {sender_bitrate_ul} Mbps\n'
@@ -830,10 +818,16 @@ class OaiCiTest():
 			cmd_ue.run(f'rm /tmp/{client_filename}', reportNonZero=False)
 		if udpIperf:
 			status, msg = Iperf_analyzeV3UDP(client_filename, self.iperf_bitrate_threshold, self.iperf_packetloss_threshold, target_bitrate)
-		elif bidirIperf:
-			status, msg = Iperf_analyzeV3BIDIRJson(client_filename)
 		else:
-			status, msg = Iperf_analyzeV3TCPJson(client_filename, self.iperf_tcp_rate_target)
+			# check if collected JSON log is valid, function returns "valid" = indication of json validity and "report" = either valid JSON object or error message
+			valid, report = get_JSON(client_filename)
+			if bidirIperf and valid:
+				status, msg = Iperf_analyzeV3BIDIRJson(report)
+			elif not bidirIperf and valid:
+				status, msg = Iperf_analyzeV3TCPJson(report, self.iperf_tcp_rate_target)
+			else:
+				status = False
+				msg = report
 
 		logging.info(f'\u001B[1;37;45m iperf result for {ue_header}\u001B[0m')
 		for l in msg.split('\n'):