Send to stderr all exceptions messages in arping check

Change-Id: I1d21c08ac650f0bbac511ca5ce059145e1273ec2
Related-bug: PROD-35728
diff --git a/telegraf/files/script/check_ovs_arping.py b/telegraf/files/script/check_ovs_arping.py
index 864131d..b6f8f2d 100644
--- a/telegraf/files/script/check_ovs_arping.py
+++ b/telegraf/files/script/check_ovs_arping.py
@@ -130,7 +130,8 @@
             return packets
         try:
             data = soc.recv(PACKETSIZE)
-        except OSError:
+        except OSError as e:
+            sys.stderr.write(str(e))
             return packets
         if len(data) == PACKETSIZE and ord(data[21]) == ARPREPLY:
             ip_to = data[38:42]
@@ -148,20 +149,26 @@
         soc = socket.socket(socket.PF_PACKET, socket.SOCK_RAW)
         try:
             soc.bind((interface, TYPEFRAME))
-        except OSError:
+        except OSError as e:
+            sys.stderr.write(str(e))
             return set(), ip_recvrs
+
         for ip_recvr in ip_recvrs:
             bc_packet = ARPSendPacket('ff:ff:ff:ff:ff:ff', mac_sedr, ip_sedr, mac_sedr, ip_recvr, '00:00:00:00:00:00')
             try:
                 soc.send(bc_packet.__str__())
-            except OSError:
+            except OSError as e:
+                sys.stderr.write(str(e))
                 return set(), ip_recvrs
+
         packets = recv_arp_packets(soc, socket.inet_aton(ip_sedr), ip_recvrs, TIMEOUT)
         res_addrs = set()
+
         for packet in packets:
             ip_from = packet[28:32]
             mac_from = packet[6:12]
             res_addrs.add((ip_from, mac_from))
+
         for _ in range(args.arp_count - 1):
             tmp_res_addrs = set()
             str_ips = set()
@@ -172,18 +179,22 @@
                 uc_packet = ARPSendPacket(mac_str, mac_sedr, ip_sedr, mac_sedr, ip_str, mac_str)
                 try:
                     soc.send(uc_packet.__str__())
-                except OSError:
+                except OSError as e:
+                    sys.stderr.write(str(e))
                     return set(), ip_recvrs
             packets = recv_arp_packets(soc, socket.inet_aton(ip_sedr), str_ips, TIMEOUT)
+
             for packet in packets:
                 ip_from = packet[28:32]
                 mac_from = packet[6:12]
                 tmp_res_addrs.add((ip_from, mac_from))
             res_addrs = tmp_res_addrs
+
         ips = set()
         for addr in res_addrs:
             ips.add(socket.inet_ntoa(addr[0]))
         soc.close()
+
         return ips, ip_recvrs.difference(ips)
 
 
@@ -207,6 +218,7 @@
     name = ""
     mac = ""
     addresses = []
+
     for line in data.split('\n'):
         m = re.match(r"(\d+):\s?(.+):", line)
         if m:
@@ -220,6 +232,7 @@
         m = re.match(r"\s+inet\s([0-9.]+)/(\d+)", line)
         if m:
             addresses.append((m.group(1), m.group(2)))
+
     interfaces[name] = {"addresses": addresses, "mac": mac}
     interfaces.pop("", None)
     interfaces.pop("lo", None)
@@ -327,8 +340,10 @@
         id = check["id"]
         try:
             passed, failed = check["result"].get()
-        except IOError:
+        except IOError as e:
+            sys.stderr.write(str(e))
             passed, failed = set(), check_map[id]
+
         for ip in passed:
             id_long = id + " " + ip
             res = mapping[id_long]
@@ -339,6 +354,7 @@
                       'id': res['device_id'],
                       'success': "1"
                   }
+
         for ip in failed:
             id_long = id + " " + ip
             res = mapping[id_long]
@@ -349,6 +365,8 @@
                       'id': res['device_id'],
                       'success': "0"
                   }
+
+
 if __name__ == "__main__":
     try:
         gather()