Function wait_for_server_healthy

libs/code/deepagents_code/server.py:226–288

Poll a LangGraph server health endpoint until it responds. Args: url: Server base URL (health endpoint is `{url}/ok`). timeout: Max seconds to wait. process: Optional subprocess handle; if the process exits early we fail fast instead of waiting for the timeou

(
    url: str,
    *,
    timeout: float = _HEALTH_TIMEOUT,  # noqa: ASYNC109
    process: subprocess.Popen | None = None,
    read_log: Callable[[], str] | None = None,
    local: bool = False,
)

async def wait_for_server_healthy(
    url: str,
    *,
    timeout: float = _HEALTH_TIMEOUT,  # noqa: ASYNC109
    process: subprocess.Popen | None = None,
    read_log: Callable[[], str] | None = None,
    local: bool = False,
) -> None:
    """Poll a LangGraph server health endpoint until it responds.

    Args:
        url: Server base URL (health endpoint is `{url}/ok`).
        timeout: Max seconds to wait.
        process: Optional subprocess handle; if the process exits early
            we fail fast instead of waiting for the timeout.
        read_log: Optional callable returning log file contents (for
            error messages on early exit).
        local: Use a shorter poll interval for local servers.

    Raises:
        RuntimeError: If the server doesn't become healthy in time.
    """
    import httpx

    poll_interval = (
        _HEALTH_POLL_INTERVAL_LOCAL if local else _HEALTH_POLL_INTERVAL_REMOTE
    )
    health_url = f"{url}/ok"
    deadline = time.monotonic() + timeout
    last_status: int | None = None
    last_exc: Exception | None = None

    async with httpx.AsyncClient() as client:
        while time.monotonic() < deadline:
            if process and process.poll() is not None:
                output = read_log() if read_log else ""
                msg = f"Server process exited with code {process.returncode}"
                if output:
                    summary = _extract_startup_error_marker(output)
                    if summary:
                        msg += f": {summary}"
                    msg += f"\n{output[-_LOG_TAIL_CHARS:]}"
                raise RuntimeError(msg)

            try:
                resp = await client.get(health_url, timeout=2)
                if resp.status_code == 200:  # noqa: PLR2004
                    logger.info("Server is healthy at %s", url)
                    return
                last_status = resp.status_code
                logger.debug("Health check returned status %d", resp.status_code)
            except (httpx.TransportError, OSError) as exc:
                logger.debug("Health check attempt failed: %s", exc)
                last_exc = exc

            await asyncio.sleep(poll_interval)

    msg = f"Server did not become healthy within {timeout}s"