Add help option for scripts

Added help options -h, --help for the script that autogenerates
the pipeline and for the one that runs the tests locally. In the
former, replaced the module optparse (which is now deprecated)
with the module argparse.

Signed-off-by: Catalin Dumitru <catdum@amazon.com>

.buildkite/autogenerate_pipeline.py

@@ -51,7 +51,8 @@ import sys
 import pathlib
 import copy
 
-from optparse import OptionParser
+from argparse import ArgumentParser, RawTextHelpFormatter
+from textwrap import dedent
 
 # This represents the version of the rust-vmm-container used
 # for running the tests.
@@ -267,14 +268,31 @@ def generate_pipeline(config_file):
 
 
 if __name__ == '__main__':
-    parser = OptionParser()
+    help_text = dedent(
+        """
+        This script supports overriding the following configurations through
+        environment variables:
+        - X86_LINUX_AGENT_TAGS: overrides the tags by which the x86_64 linux
+        agent is selected.
+        - AARCH64_LINUX_AGENT_TAGS: overrides the tags by which the aarch64
+        linux agent is selected.
+        - DOCKER_PLUGIN_CONFIG: specifies additional configuration for the
+        docker plugin. For available configuration, please check
+        https://github.com/buildkite-plugins/docker-buildkite-plugin.
+        - TESTS_TO_SKIP: specifies a list of tests to be skipped.
+        """
+    )
+    parser = ArgumentParser(description=help_text,
+                            formatter_class=RawTextHelpFormatter)
     # By default we're generating the rust-vmm-ci pipeline with the test
     # configuration committed to this repository.
     # This parameter is useful for generating the pipeline for repositories
     # that have custom pipelines, and it helps with keeping the container
     # version the same across pipelines.
-    parser.add_option("-t", "--test-description", dest="test_description",
-                      help="JSON file containing the test description.",
-                      default=f"{PARENT_DIR}/test_description.json")
-    (options, args) = parser.parse_args()
-    generate_pipeline(options.test_description)
+    parser.add_argument('-t', '--test-description',
+                        metavar="JSON_FILE",
+                        help='The path to the JSON file containing the test'
+                             ' description for the CI.',
+                        default=f'{PARENT_DIR}/test_description.json')
+    args = parser.parse_args()
+    generate_pipeline(args.test_description)

test_run.py

@@ -8,6 +8,9 @@ import platform
 import pathlib
 import unittest
 
+from argparse import ArgumentParser, RawTextHelpFormatter
+from textwrap import dedent
+
 PARENT_DIR = pathlib.Path(__file__).parent.resolve()
 
 
@@ -31,6 +34,20 @@ def retrieve_test_list(
 
 
 if __name__ == '__main__':
+    help_text = dedent(
+        """
+        This script allows running all the tests at once on the local machine.
+        The tests "test_benchmark.py" and "test_commit_format.py" work properly
+        on the local machine only when the environment variables REMOTE and
+        BASE_BRANCH are set. Otherwise the default values are "origin" for the
+        remote name of the upstream repository and "master" for the name of the
+        base branch, and these tests may not work as expected.
+        """
+    )
+    parser = ArgumentParser(description=help_text,
+                            formatter_class=RawTextHelpFormatter)
+    parser.parse_args()
+
     test_config = retrieve_test_list()
     for test in test_config['tests']:
         command = test['command']