pyworker/workers/comfyui-json/worker.py

"""ComfyUI worker for the vast.ai PyWorker SDK.

Each worker runs a benchmark on warm-up. The payload is selected as follows:

  1. If ``misc/benchmark.json`` exists in the cloned worker tree, it is
     used as a custom ComfyUI workflow. Use this if you fork the repo and
     bake in your workflow.
  2. Else, if ``$BENCHMARK_JSON_PATH`` is set and points at a readable
     file, it is used. Use this from a provisioning script — provisioning
     runs before pyworker is cloned, so it cannot write into ``misc/``,
     but it can drop the workflow elsewhere (e.g. ``/workspace/``) and
     export this env var.
  3. Else, if the well-known path
     ``/opt/comfyui-api-wrapper/workflows/pyworker_benchmark.json`` exists,
     it is used. The vast.ai ComfyUI base image's ``convert-workflows.sh``
     maintains this as a symlink to the first provisioned workflow, so on
     that image no env var is needed.
  4. Otherwise an SD1.5 Text2Image fallback runs, parameterised by the
     ``BENCHMARK_TEST_{WIDTH,HEIGHT,STEPS}`` env vars and a random prompt
     from ``misc/test_prompts.txt``.

``__RANDOM_INT__`` placeholders in custom workflows are substituted
server-side by ai-dock/comfyui-api-wrapper, so this worker does not handle
them itself.
"""

import json
import logging
import os
import random
import sys
from pathlib import Path

from vastai import Worker, WorkerConfig, HandlerConfig, LogActionConfig, BenchmarkConfig

# ComfyUI model configuration. The model server here is the ai-dock
# comfyui-api-wrapper sitting in front of ComfyUI itself, not ComfyUI's
# own port (18188). We watch the api-wrapper's log rather than ComfyUI's
# because the api-wrapper runs convert-workflows.sh before launching
# uvicorn — by the time uvicorn logs "Uvicorn running on ...", the
# benchmark workflows are converted, the pyworker_benchmark.json symlink
# exists, and :18288 is accepting connections. Watching ComfyUI's log
# fires the benchmark too early (before the api-wrapper is reachable),
# which the SDK can't recover from since __call_backend doesn't retry
# connection-refused.
MODEL_SERVER_URL           = 'http://127.0.0.1'
MODEL_SERVER_PORT          = 18288
MODEL_LOG_FILE             = '/var/log/portal/api-wrapper.log'
MODEL_HEALTHCHECK_ENDPOINT = "/health"

# api-wrapper log messages
MODEL_LOAD_LOG_MSG = [
    "Uvicorn running on"
]

# LogAction.ModelError is fatal: the SDK calls backend_errored() and the
# worker is locked into a permanent error state. Patterns must therefore
# only match conditions where the api-wrapper genuinely cannot serve any
# request — supervisord restarts on uvicorn exit, so a real failure
# self-heals rather than dragging the worker down.
#
# Notably *not* matched here:
#   - per-request errors (PreprocessWorker failures, ComfyUI workflow
#     validation, "Value not in list:") — one malformed client payload
#     would otherwise kill the worker
#   - "CUDA out of memory" — surfaces both as misconfigured GPU (which
#     the benchmark-failure path already catches via backend_errored)
#     and as a too-greedy client request, which is indistinguishable
#     from a substring match
#   - convert-workflows.sh warnings — that script is not load-bearing
#     for serving (uvicorn starts even if conversion partially failed)
MODEL_ERROR_LOG_MSGS = [
    "Application startup failed",  # uvicorn ASGI lifespan startup failed -> uvicorn exits
]

# LogAction.Info is purely informational (echoes log lines into the vast
# console). Nothing in api-wrapper.log is currently worth surfacing —
# model downloads are upstream in provisioning, per-request logs are
# too noisy.
MODEL_INFO_LOG_MSGS = []

# Benchmark assets shipped alongside this worker. Resolved relative to this
# file so the worker keeps working regardless of the launch cwd.
MISC_DIR       = Path(__file__).parent / "misc"
BENCHMARK_FILE = MISC_DIR / "benchmark.json"
TEST_PROMPTS   = MISC_DIR / "test_prompts.txt"

# Well-known location maintained by the vast.ai ComfyUI base image.
# convert-workflows.sh symlinks this to the first provisioned workflow,
# letting the base image work out-of-the-box without any env var.
WELLKNOWN_BENCHMARK = Path("/opt/comfyui-api-wrapper/workflows/pyworker_benchmark.json")

log = logging.getLogger(__name__)

# Used when test_prompts.txt is unreadable or empty. Bare and generic
# on purpose — this is a benchmark seed, not a creative output.
_FALLBACK_PROMPT = "a still life on a wooden table, soft daylight"


def _env_int(name: str, default: int) -> int:
    """Read an integer env var, warning + falling back on bad values."""
    raw = os.getenv(name)
    if raw is None or raw == "":
        return default
    try:
        return int(raw)
    except ValueError:
        log.warning("ignoring %s=%r (not an int); using default %d", name, raw, default)
        return default


def _try_load_workflow(path: Path) -> dict | None:
    """Load and return a benchmark workflow from ``path``.

    Returns None on any failure (path missing, not a regular file,
    unreadable, invalid JSON) so the caller can fall through to the
    next tier rather than dropping straight to the SD1.5 default.
    """
    if not path.is_file():
        return None
    try:
        with open(path) as f:
            return json.load(f)
    except (json.JSONDecodeError, OSError) as e:
        log.warning("Failed to load %s: %s; trying next tier", path, e)
        return None


def _custom_workflow_payload() -> dict | None:
    """Try each benchmark workflow tier in order; return the first one
    that loads cleanly as a payload, or None if every tier is absent /
    unreadable. Tiers (in order): in-tree ``misc/benchmark.json``,
    ``$BENCHMARK_JSON_PATH``, well-known base-image symlink.
    """
    env_path = os.getenv("BENCHMARK_JSON_PATH")
    candidates = [("misc", BENCHMARK_FILE)]
    if env_path:
        candidates.append(("env", Path(env_path)))
    candidates.append(("well-known", WELLKNOWN_BENCHMARK))

    for label, path in candidates:
        # Surface a warning specifically when the operator pointed
        # BENCHMARK_JSON_PATH at something we can't use — silent
        # fall-through there is a footgun (typo => SD1.5 fallback,
        # operator wonders why custom benchmark didn't take).
        if not path.is_file():
            if label == "env":
                log.warning(
                    "BENCHMARK_JSON_PATH=%s is not a readable file; trying fallbacks", path
                )
            continue
        workflow = _try_load_workflow(path)
        if workflow is None:
            continue
        log.info("Using custom benchmark workflow from %s (%s)", path, label)
        return {
            "input": {
                "request_id": f"test-{random.randint(1000, 99999)}",
                "workflow_json": workflow,
            }
        }
    return None


def _load_prompts() -> list[str]:
    """Read misc/test_prompts.txt; defensive against missing/empty file."""
    try:
        with open(TEST_PROMPTS) as f:
            prompts = [line.strip() for line in f if line.strip()]
    except OSError as e:
        log.warning("could not read %s: %s; using built-in fallback prompt", TEST_PROMPTS, e)
        return [_FALLBACK_PROMPT]
    if not prompts:
        log.warning("%s is empty; using built-in fallback prompt", TEST_PROMPTS)
        return [_FALLBACK_PROMPT]
    return prompts


def _default_payload() -> dict:
    """Build the SD1.5 Text2Image fallback payload."""
    prompts = _load_prompts()
    return {
        "input": {
            "request_id": f"test-{random.randint(1000, 99999)}",
            "modifier": "Text2Image",
            "modifications": {
                "prompt": random.choice(prompts),
                "width":  _env_int("BENCHMARK_TEST_WIDTH",  512),
                "height": _env_int("BENCHMARK_TEST_HEIGHT", 512),
                "steps":  _env_int("BENCHMARK_TEST_STEPS",  20),
                "seed":   random.randint(0, sys.maxsize),
            }
        }
    }


def make_benchmark_payload() -> dict:
    """Build one benchmark request payload.

    Called once per benchmark run by the SDK; using a generator (rather
    than a static ``dataset=``) lets each run re-pick a prompt and re-roll
    the seed, and avoids holding multiple copies of a large workflow JSON
    in memory.
    """
    return _custom_workflow_payload() or _default_payload()


worker_config = WorkerConfig(
    model_server_url=MODEL_SERVER_URL,
    model_server_port=MODEL_SERVER_PORT,
    model_log_file=MODEL_LOG_FILE,
    model_healthcheck_url=MODEL_HEALTHCHECK_ENDPOINT,
    handlers=[
        HandlerConfig(
            route="/generate/sync",
            allow_parallel_requests=False,
            max_queue_time=10.0,
            benchmark_config=BenchmarkConfig(
                generator=make_benchmark_payload,
            )
        )
    ],
    log_action_config=LogActionConfig(
        on_load=MODEL_LOAD_LOG_MSG,
        on_error=MODEL_ERROR_LOG_MSGS,
        on_info=MODEL_INFO_LOG_MSGS
    )
)

Worker(worker_config).run()