Add cli run batch (#4237)

* feat(log):add_request_and_response_log

* [cli] add run batch cli

---------

Co-authored-by: Jiang-Jia-Jun <163579578+Jiang-Jia-Jun@users.noreply.github.com>

fastdeploy/utils.py

@@ -24,6 +24,7 @@ import os
 import random
 import re
 import socket
+import subprocess
 import sys
 import tarfile
 import time
@@ -57,6 +58,98 @@ from typing import Callable, Optional
 # Make sure enable_xxx equal to config.enable_xxx
 ARGS_CORRECTION_LIST = [["early_stop_config", "enable_early_stop"], ["graph_optimization_config", "use_cudagraph"]]
 
+FASTDEPLOY_SUBCMD_PARSER_EPILOG = (
+    "Tip: Use `fastdeploy [serve|run-batch|bench <bench_type>] "
+    "--help=<keyword>` to explore arguments from help.\n"
+    "   - To view a argument group:     --help=ModelConfig\n"
+    "   - To view a single argument:    --help=max-num-seqs\n"
+    "   - To search by keyword:         --help=max\n"
+    "   - To list all groups:           --help=listgroup\n"
+    "   - To view help with pager:      --help=page"
+)
+
+
+def show_filtered_argument_or_group_from_help(parser: argparse.ArgumentParser, subcommand_name: list[str]):
+
+    # Only handle --help=<keyword> for the current subcommand.
+    # Since subparser_init() runs for all subcommands during CLI setup,
+    # we skip processing if the subcommand name is not in sys.argv.
+    # sys.argv[0] is the program name. The subcommand follows.
+    # e.g., for `vllm bench latency`,
+    # sys.argv is `['vllm', 'bench', 'latency', ...]`
+    # and subcommand_name is "bench latency".
+    if len(sys.argv) <= len(subcommand_name) or sys.argv[1 : 1 + len(subcommand_name)] != subcommand_name:
+        return
+
+    for arg in sys.argv:
+        if arg.startswith("--help="):
+            search_keyword = arg.split("=", 1)[1]
+
+            # Enable paged view for full help
+            if search_keyword == "page":
+                help_text = parser.format_help()
+                _output_with_pager(help_text)
+                sys.exit(0)
+
+            # List available groups
+            if search_keyword == "listgroup":
+                output_lines = ["\nAvailable argument groups:"]
+                for group in parser._action_groups:
+                    if group.title and not group.title.startswith("positional arguments"):
+                        output_lines.append(f"  - {group.title}")
+                        if group.description:
+                            output_lines.append("    " + group.description.strip())
+                        output_lines.append("")
+                _output_with_pager("\n".join(output_lines))
+                sys.exit(0)
+
+            # For group search
+            formatter = parser._get_formatter()
+            for group in parser._action_groups:
+                if group.title and group.title.lower() == search_keyword.lower():
+                    formatter.start_section(group.title)
+                    formatter.add_text(group.description)
+                    formatter.add_arguments(group._group_actions)
+                    formatter.end_section()
+                    _output_with_pager(formatter.format_help())
+                    sys.exit(0)
+
+            # For single arg
+            matched_actions = []
+
+            for group in parser._action_groups:
+                for action in group._group_actions:
+                    # search option name
+                    if any(search_keyword.lower() in opt.lower() for opt in action.option_strings):
+                        matched_actions.append(action)
+
+            if matched_actions:
+                header = f"\nParameters matching '{search_keyword}':\n"
+                formatter = parser._get_formatter()
+                formatter.add_arguments(matched_actions)
+                _output_with_pager(header + formatter.format_help())
+                sys.exit(0)
+
+            print(f"\nNo group or parameter matching '{search_keyword}'")
+            print("Tip: use `--help=listgroup` to view all groups.")
+            sys.exit(1)
+
+
+def _output_with_pager(text: str):
+    """Output text using scrolling view if available and appropriate."""
+
+    pagers = ["less -R", "more"]
+    for pager_cmd in pagers:
+        try:
+            proc = subprocess.Popen(pager_cmd.split(), stdin=subprocess.PIPE, text=True)
+            proc.communicate(input=text)
+            return
+        except (subprocess.SubprocessError, OSError, FileNotFoundError):
+            continue
+
+    # No pager worked, fall back to normal print
+    print(text)
+
 
 class EngineError(Exception):
     """Base exception class for engine errors"""