feat: add list built stacks

Signed-off-by: reidliu <reid201711@gmail.com>

llama_stack/cli/stack/list.py

@@ -0,0 +1,50 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+import argparse
+import os
+import time
+
+from llama_stack.cli.subcommand import Subcommand
+from llama_stack.distribution.utils.config_dirs import DISTRIBS_BASE_DIR
+
+
+class StackList(Subcommand):
+    def __init__(self, subparsers: argparse._SubParsersAction):
+        super().__init__()
+        self.parser = subparsers.add_parser(
+            "list",
+            prog="llama stack list",
+            description="List the built stacks",
+            formatter_class=argparse.RawTextHelpFormatter,
+        )
+        self._add_arguments()
+        self.parser.set_defaults(func=self._run_stack_list_cmd)
+
+    def _add_arguments(self):
+        pass
+
+    def _run_stack_list_cmd(self, args: argparse.Namespace) -> None:
+        from llama_stack.cli.table import print_table
+
+        headers = ["Stack(s)", "Modified Time"]
+
+        rows = []
+        for stack in os.listdir(DISTRIBS_BASE_DIR):
+            abs_path = os.path.join(DISTRIBS_BASE_DIR, stack)
+            modified_time = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(os.path.getmtime(abs_path)))
+            rows.append(
+                [
+                    stack,
+                    modified_time,
+                ]
+            )
+
+        print_table(
+            rows,
+            headers,
+            separate_rows=True,
+        )

llama_stack/cli/stack/stack.py

@@ -11,6 +11,7 @@ from llama_stack.cli.stack.utils import print_subcommand_description
 from llama_stack.cli.subcommand import Subcommand
 
 from .build import StackBuild
+from .list import StackList
 from .list_apis import StackListApis
 from .list_providers import StackListProviders
 from .run import StackRun
@@ -38,6 +39,7 @@ class StackParser(Subcommand):
 
         # Add sub-commands
         StackBuild.create(subparsers)
+        StackList.create(subparsers)
         StackListApis.create(subparsers)
         StackListProviders.create(subparsers)
         StackRun.create(subparsers)