CI/socket examples: Add UDP operation retries, wait until server is up

examples/protocols/sockets/udp_server/example_test.py

@@ -27,9 +27,10 @@ def udp_client(address, payload):
         family_addr, socktype, proto, canonname, addr = res
     try:
         sock = socket.socket(family_addr, socket.SOCK_DGRAM)
-        sock.settimeout(60.0)
+        sock.settimeout(20.0)
     except socket.error as msg:
-        print('Could not create socket: ' + str(msg[0]) + ': ' + msg[1])
+        print('Could not create socket')
+        print(os.strerror(msg.errno))
         raise
     try:
         sock.sendto(payload.encode(), addr)
@@ -37,8 +38,12 @@ def udp_client(address, payload):
         if not reply:
             return
         print('Reply[' + addr[0] + ':' + str(addr[1]) + '] - ' + str(reply))
+    except socket.timeout:
+        print('Socket operation timeout')
+        return str(None)
     except socket.error as msg:
-        print('Error Code : ' + str(msg[0]) + ' Message: ' + msg[1])
+        print('Error while sending or receiving data from the socket')
+        print(os.strerror(msg.errno))
         sock.close()
         raise
     return reply.decode()
@@ -47,6 +52,7 @@ def udp_client(address, payload):
 @ttfw_idf.idf_example_test(env_tag='Example_WIFI')
 def test_examples_protocol_socket_udpserver(env, extra_data):
     MESSAGE = 'Data to ESP'
+    MAX_RETRIES = 3
     """
     steps:
       1. join AP
@@ -66,16 +72,28 @@ def test_examples_protocol_socket_udpserver(env, extra_data):
     ipv6_r = r':'.join((r'[0-9a-fA-F]{4}',) * 8)    # expect all 8 octets from IPv6 (assumes it's printed in the long form)
     ipv6 = dut1.expect(re.compile(r' IPv6 address: ({})'.format(ipv6_r)), timeout=30)[0]
     print('Connected with IPv4={} and IPv6={}'.format(ipv4, ipv6))
+    dut1.expect(re.compile(r'Waiting for data'), timeout=10)
 
     # test IPv4
-    received = udp_client(ipv4, MESSAGE)
-    if not received == MESSAGE:
-        raise
+    for _ in range(MAX_RETRIES):
+        print('Testing UDP on IPv4...')
+        received = udp_client(ipv4, MESSAGE)
+        if received == MESSAGE:
+            print('OK')
+            break
+    else:
+        raise ValueError('IPv4: Did not receive UDP message after {} retries'.format(MAX_RETRIES))
     dut1.expect(MESSAGE)
+
     # test IPv6
-    received = udp_client('{}%{}'.format(ipv6, INTERFACE), MESSAGE)
-    if not received == MESSAGE:
-        raise
+    for _ in range(MAX_RETRIES):
+        print('Testing UDP on IPv6...')
+        received = udp_client('{}%{}'.format(ipv6, INTERFACE), MESSAGE)
+        if received == MESSAGE:
+            print('OK')
+            break
+    else:
+        raise ValueError('IPv6: Did not receive UDP message after {} retries'.format(MAX_RETRIES))
     dut1.expect(MESSAGE)