[sonic-package-manager] fix CLI plugin compatibility issue (sonic-net#2842)

- What I did
Overcome a CLI plugin compatibility issue

- How I did it
DHCP relay extension expects the spm to name its plugin "dhcp-relay". This change keeps that format if there is just one CLI plugin.

Signed-off-by: Stepan Blyschak <[email protected]>

Author: stepanblyschak

sonic_package_manager/manager.py

@@ -171,7 +171,11 @@ def get_cli_plugin_path(package: Package, index: int, command: str) -> str:
         Path generated for this package.
     """
 
-    plugin_module_file = f'{package.name}_{index}.py'
+    if index == 0:
+        plugin_module_file = f'{package.name}.py'
+    else:
+        plugin_module_file = f'{package.name}_{index}.py'
+
     return os.path.join(get_cli_plugin_directory(command), plugin_module_file)
 
 

tests/sonic_package_manager/test_manager.py

@@ -165,7 +165,7 @@ def test_installation_cli_plugin(package_manager, fake_metadata_resolver, anythi
     with patch('sonic_package_manager.manager.get_cli_plugin_directory') as get_dir_mock:
         get_dir_mock.return_value = '/'
         package_manager.install('test-package')
-        package_manager.docker.extract.assert_called_once_with(anything, '/cli/plugin.py', '/test-package_0.py')
+        package_manager.docker.extract.assert_called_once_with(anything, '/cli/plugin.py', '/test-package.py')
 
 
 def test_installation_multiple_cli_plugin(package_manager, fake_metadata_resolver, mock_feature_registry, anything):
@@ -178,7 +178,7 @@ def test_installation_multiple_cli_plugin(package_manager, fake_metadata_resolve
         package_manager.install('test-package')
         package_manager.docker.extract.assert_has_calls(
             [
-                call(anything, '/cli/plugin.py', '/test-package_0.py'),
+                call(anything, '/cli/plugin.py', '/test-package.py'),
                 call(anything, '/cli/plugin2.py', '/test-package_1.py'),
             ],
             any_order=True,
@@ -188,7 +188,7 @@ def test_installation_multiple_cli_plugin(package_manager, fake_metadata_resolve
         package_manager.uninstall('test-package', force=True)
         remove_mock.assert_has_calls(
             [
-                call('/test-package_0.py'),
+                call('/test-package.py'),
                 call('/test-package_1.py'),
             ],
             any_order=True,