make test: improve robustness and performance

Introduce an API which asserts empty capture for interface.
Throw exception in old API if the capture does not exist, thus
making it clear if the test expects packets to arrive or not.
Improve performance by not doing sleeps after starting the packet
generator, rather lazily deleting captures when needed.
Fix wrong usage of packet.show() in various tests.

Change-Id: I456cb23316eef99b3f35f80344fe595c4db9a21c
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 6 insertions, 23 deletions

diff --git a/test/test_mpls.py b/test/test_mpls.py
index 24fc4129ecd..6d5eeb2bf88 100644
--- a/test/test_mpls.py
+++ b/test/test_mpls.py
@@ -11,8 +11,6 @@ from scapy.layers.l2 import Ether
 from scapy.layers.inet import IP, UDP, ICMP
 from scapy.layers.inet6 import IPv6
 from scapy.contrib.mpls import MPLS
-from util import ppp
-
 
 class TestMPLS(VppTestCase):
     """ MPLS Test Case """
@@ -60,7 +58,7 @@ class TestMPLS(VppTestCase):
                 else:
                     p = p / MPLS(label=mpls_labels[ii], ttl=mpls_ttl, s=0)
             if not ping:
-                p = (p / IP(src=src_if.local_ip4, dst=src_if.remote_ip4) / 
+                p = (p / IP(src=src_if.local_ip4, dst=src_if.remote_ip4) /
                      UDP(sport=1234, dport=1234) /
                      Raw(payload))
             else:
@@ -331,14 +329,8 @@ class TestMPLS(VppTestCase):
 
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-
-        rx = self.pg0.get_capture()
-        try:
-            self.assertEqual(0, len(rx))
-        except:
-            self.logger.error("MPLS non-EOS packets popped and forwarded")
-            self.logger.error(ppp("", rx))
-            raise
+        self.pg0.assert_nothing_captured(
+            remark="MPLS non-EOS packets popped and forwarded")
 
         #
         # A recursive EOS x-connect, which resolves through another x-connect
@@ -586,8 +578,7 @@ class TestMPLS(VppTestCase):
             0,  # next-hop-table-id
             1,  # next-hop-weight
             2,  # num-out-labels,
-            [44, 46]
-        )
+            [44, 46])
         self.vapi.sw_interface_set_flags(reply.sw_if_index, admin_up_down=1)
 
         #
@@ -606,8 +597,7 @@ class TestMPLS(VppTestCase):
             0,  # next-hop-table-id
             1,  # next-hop-weight
             0,  # num-out-labels,
-            []  # out-label
-        )
+            [])  # out-label
 
         self.vapi.cli("clear trace")
         tx = self.create_stream_ip4(self.pg0, "10.0.0.3")
@@ -632,14 +622,7 @@ class TestMPLS(VppTestCase):
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
-        rx = self.pg0.get_capture()
-
-        try:
-            self.assertEqual(0, len(rx))
-        except:
-            self.logger.error("MPLS TTL=0 packets forwarded")
-            self.logger.error(ppp("", rx))
-            raise
+        self.pg0.assert_nothing_captured(remark="MPLS TTL=0 packets forwarded")
 
         #
         # a stream with a non-zero MPLS TTL