load_gen: Supporting loading of load_gen via loader.

Currently all tools are loaded via loader utility, except load_gen.
Load_gens were loaded directly through component_factory.
This patch adds support to load load_gens through loader utility.

The changes are as follows:
1. Configuration changes:The common.conf include configuration of
   directory. testcases.conf includes changes to load configuration,
   where tool is no more part of the load-configuration. The
   custom.conf has configuration of LOADGEN to be used - this configuration
   replaces the earlier 'tool' configuration parameter.
2. loader_utility_changes:  In loader.py, loadgen_loader is
   defined, which is used in new get_loadgen function.
3. component_factory changes: in create_loadgen, similar
   to other tools, the function just retuns the object of loadgen_class.
4. Renaming of Dummy load_gen: Loader fails to load properly a dummy
   loadgen due to name-clash with dummy in pkt_gen. To avoid this name clash
   dummy is renamed to dummyloadgen.
5. testcase changes: create_loadgen is now called with output of
   loader's get_loadgen_class.
6. Fixed Pylint Errors and extra-space at the end.
7. Included CLI options support for --loadgen and --list-loadgens.
   Thanks to Martin K.
8. Added the missing loadgen parameter in testcases.conf.
9. Fixed the missing comma error.
10. Added CI change in build-vsperf.sh
11. Fixed configuration reading in stress/stress.py

JIRA: VSPERF-533

Change-Id: I3fbb259618825a12fef55320a748a4f02509190b
Signed-off-by: Sridhar K. N. Rao <sridhar.rao@spirent.com>
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/tools/load_gen/dummyloadgen/dummyloadgen.py b/tools/load_gen/dummyloadgen/dummyloadgen.py
new file mode 100644
index 00000000..91bef4fa
--- /dev/null
+++ b/tools/load_gen/dummyloadgen/dummyloadgen.py
@@ -0,0 +1,32 @@
+# Copyright 2015-2017 Intel Corporation.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Class with implementation of wrapper of dummy load generator"""
+
+from tools.load_gen.load_gen import ILoadGenerator
+
+# pylint: disable=super-init-not-called
+class DummyLoadGen(ILoadGenerator):
+    """Dummy load generator, which doesn't generate any load"""
+    def __init__(self, stress_config):
+        """Initialise process state."""
+        pass
+
+    def start(self):
+        """Start stress load if it was requested"""
+        pass
+
+    def kill(self, dummy_signal='-15', dummy_sleep=2):
+        """Kill stress load if it is active"""
+        pass