add helpful options to cli

sdk/python/kfp/cli/cli.py

@@ -12,12 +12,46 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
+
 import click
+import kfp
 from kfp.cli.output import OutputFormat
 from kfp.client import Client
 
+PROGRAM_NAME = 'kfp'
+SHELL_FILES = {
+    'bash': ['.bashrc'],
+    'zsh': ['.zshrc'],
+    'fish': ['.config', 'fish', 'completions', f'{PROGRAM_NAME}.fish']
+}
+
+
+def _create_completion(shell: str) -> str:
+    return f'eval "$(_{PROGRAM_NAME.upper()}_COMPLETE={shell}_source {PROGRAM_NAME})"'
+
+
+def _show_completion(shell: str) -> None:
+    click.echo(_create_completion(shell))
+
+
+def _install_completion(shell: str) -> None:
+    completion_statement = _create_completion(shell)
+    source_file = os.path.join(os.path.expanduser('~'), *SHELL_FILES[shell])
+    print("SOURCE FILE: ", source_file)
+    with open(source_file, 'a') as f:
+        f.write(completion_statement + '\n')
 
-@click.group()
+
+@click.group(invoke_without_command=True)
+@click.option(
+    '--show-completion',
+    type=click.Choice(list(SHELL_FILES.keys())),
+    default=None)
+@click.option(
+    '--install-completion',
+    type=click.Choice(list(SHELL_FILES.keys())),
+    default=None)
 @click.option('--endpoint', help='Endpoint of the KFP API service to connect.')
 @click.option('--iap-client-id', help='Client ID for IAP protected endpoint.')
 @click.option(
@@ -39,13 +73,22 @@
     show_default=True,
     help='The formatting style for command output.')
 @click.pass_context
+@click.version_option(version=kfp.__version__, message="%(prog)s %(version)s")
 def cli(ctx: click.Context, endpoint: str, iap_client_id: str, namespace: str,
-        other_client_id: str, other_client_secret: str, output: OutputFormat):
+        other_client_id: str, other_client_secret: str, output: OutputFormat,
+        show_completion: str, install_completion: str):
     """kfp is the command line interface to KFP service.
 
     Feature stage:
     [Alpha](https://github.com/kubeflow/pipelines/blob/07328e5094ac2981d3059314cc848fbb71437a76/docs/release/feature-stages.md#alpha)
     """
+    if show_completion:
+        _show_completion(show_completion)
+        return
+    if install_completion:
+        _install_completion(install_completion)
+        return
+
     NO_CLIENT_COMMANDS = ['diagnose_me', 'components']
     if ctx.invoked_subcommand in NO_CLIENT_COMMANDS:
         # Do not create a client for these subcommands