pyro-mcp/examples/langchain_vm_run.py

95 lines
2.6 KiB
Python

"""Thin LangChain wrapper over the public vm_run contract.
Requirements:
- `pip install langchain-core` or `uv add langchain-core`
This example keeps the framework integration intentionally narrow: a single tool
that delegates straight to `Pyro.run_in_vm(...)`.
"""
from __future__ import annotations
import json
from typing import Any, Callable, TypeVar, cast
from pyro_mcp import Pyro
from pyro_mcp.vm_manager import (
DEFAULT_ALLOW_HOST_COMPAT,
DEFAULT_MEM_MIB,
DEFAULT_TIMEOUT_SECONDS,
DEFAULT_TTL_SECONDS,
DEFAULT_VCPU_COUNT,
)
F = TypeVar("F", bound=Callable[..., Any])
def run_vm_run_tool(
*,
environment: str,
command: str,
vcpu_count: int = DEFAULT_VCPU_COUNT,
mem_mib: int = DEFAULT_MEM_MIB,
timeout_seconds: int = DEFAULT_TIMEOUT_SECONDS,
ttl_seconds: int = DEFAULT_TTL_SECONDS,
network: bool = False,
allow_host_compat: bool = DEFAULT_ALLOW_HOST_COMPAT,
) -> str:
pyro = Pyro()
result = pyro.run_in_vm(
environment=environment,
command=command,
vcpu_count=vcpu_count,
mem_mib=mem_mib,
timeout_seconds=timeout_seconds,
ttl_seconds=ttl_seconds,
network=network,
allow_host_compat=allow_host_compat,
)
return json.dumps(result, sort_keys=True)
def build_langchain_vm_run_tool() -> Any:
try:
from langchain_core.tools import tool # type: ignore[import-not-found]
except ImportError as exc: # pragma: no cover - dependency guard
raise RuntimeError(
"langchain-core is required for this example. Install it with "
"`uv add langchain-core` or `pip install langchain-core`."
) from exc
decorator = cast(Callable[[F], F], tool("vm_run"))
@decorator
def vm_run(
environment: str,
command: str,
vcpu_count: int = DEFAULT_VCPU_COUNT,
mem_mib: int = DEFAULT_MEM_MIB,
timeout_seconds: int = DEFAULT_TIMEOUT_SECONDS,
ttl_seconds: int = DEFAULT_TTL_SECONDS,
network: bool = False,
allow_host_compat: bool = DEFAULT_ALLOW_HOST_COMPAT,
) -> str:
"""Run one command in an ephemeral Firecracker VM and clean it up."""
return run_vm_run_tool(
environment=environment,
command=command,
vcpu_count=vcpu_count,
mem_mib=mem_mib,
timeout_seconds=timeout_seconds,
ttl_seconds=ttl_seconds,
network=network,
allow_host_compat=allow_host_compat,
)
return vm_run
def main() -> None:
tool = build_langchain_vm_run_tool()
print(tool)
if __name__ == "__main__":
main()