paths: Modify algorithm for PATHS verification

VSPERF verifies if PATHS to the tools (vSwitch, VNF, etc.)
are valid. This check was modified to take into the account
tools required by selected testcase. It will help to avoid
runtime errors triggered by missing tools, which
are not essential for testcase execution.

Change-Id: Ifcfea983cad1bdbc8c1f08c7a0281001005410df
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Christian Trautman <ctrautma@redhat.com>
Reviewed-by: Sridhar Rao <sridhar.rao@spirent.com>
Reviewed-by: Trevor Cooper <trevor.cooper@intel.com>

1 files changed, 14 insertions, 5 deletions

diff --git a/tools/pkt_gen/trex/trex.py b/tools/pkt_gen/trex/trex.py
index abae35dc..70864a53 100644
--- a/tools/pkt_gen/trex/trex.py
+++ b/tools/pkt_gen/trex/trex.py
@@ -27,9 +27,18 @@ from conf import settings
 from conf import merge_spec
 from core.results.results_constants import ResultsConstants
 from tools.pkt_gen.trafficgen.trafficgen import ITrafficGenerator
-# pylint: disable=wrong-import-position, import-error
-sys.path.append(settings.getValue('PATHS')['trafficgen']['trex']['src']['path'])
-from trex_stl_lib.api import *
+try:
+    # pylint: disable=wrong-import-position, import-error
+    sys.path.append(settings.getValue('PATHS')['trafficgen']['Trex']['src']['path'])
+    from trex_stl_lib.api import *
+except ImportError:
+    # VSPERF performs detection of T-Rex api during testcase initialization. So if
+    # T-Rex is requsted and API is not available it will fail before this code
+    # is reached.
+    # This code can be reached in case that --list-trafficgens is called, but T-Rex
+    # api is not installed. In this case we can ignore an exception, becuase T-Rex
+    # import won't be used.
+    pass
 
 _EMPTY_STATS = {
     'global': {'bw_per_core': 0.0,
@@ -337,8 +346,8 @@ class Trex(ITrafficGenerator):
         raise NotImplementedError(
             'Trex stop_cont_traffic method not implemented')
 
-    def send_rfc2544_throughput(self, traffic=None, duration=60,
-                                lossrate=0.0, tests=10):
+    def send_rfc2544_throughput(self, traffic=None, tests=1, duration=60,
+                                lossrate=0.0):
         """See ITrafficGenerator for description
         """
         self._logger.info("In Trex send_rfc2544_throughput method")