[fix] Fixed iperf check execution if device connection not working #399

- We need to check device_connection is_working just right after connect().
- because it may be possible that authentication (publickey) failed.
- or any other failure happened during connect().

Fixes #399

openwisp_monitoring/check/classes/iperf.py

@@ -26,6 +26,12 @@ def check(self, store=True):
             logger.warning(f'{device}: connection not properly set, Iperf skipped!')
             return
         device_connection.connect()
+        # We need to check device_connection is_working just right after connect().
+        # because it may be possible that authentication (publickey) failed.
+        # or any other failure happened during connect().
+        if not device_connection.is_working:
+            logger.warning(f'{device}: SSH connection is not working, Iperf skipped!')
+            return
         servers = self._get_iperf_servers(device.organization.id)
         command = f'iperf3 -c {servers[0]} -J'
         res, exit_code = device_connection.connector_instance.exec_command(

tests/openwisp2/settings.py

@@ -274,7 +274,8 @@
     # Running on my local
     # Some Public Iperf Servers : https://iperf.fr/iperf-servers.php#public-servers
     # 'be63c4e5-a68a-4650-bfe8-733837edb8be': ['iperf.biznetnetworks.com'],
-    'a9734710-db30-46b0-a2fc-01f01046fe4f': ['speedtest.uztelecom.uz'],
+    # 'a9734710-db30-46b0-a2fc-01f01046fe4f': ['speedtest.uztelecom.uz'],
+    'a9734710-db30-46b0-a2fc-01f01046fe4f': ['192.168.5.109'],
     # '<org-pk>': ['<ORG_IPERF_SERVER>']
 }