shoehorning graphql, step functions and lamdas. aws deployment scripts

task/lambda_handler.py

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+"""
+AWS Lambda handler for media transcoding.
+
+Receives a job payload from Step Functions, downloads source from S3,
+runs FFmpeg, uploads result to S3, and calls back to the API.
+
+Uses the same core/ffmpeg module as the local Celery worker.
+"""
+
+import json
+import logging
+import os
+import tempfile
+from pathlib import Path
+
+import boto3
+import requests
+
+logger = logging.getLogger()
+logger.setLevel(logging.INFO)
+
+# S3 config
+S3_BUCKET_IN = os.environ.get("S3_BUCKET_IN", "mpr-media-in")
+S3_BUCKET_OUT = os.environ.get("S3_BUCKET_OUT", "mpr-media-out")
+AWS_REGION = os.environ.get("AWS_REGION", "us-east-1")
+
+s3 = boto3.client("s3", region_name=AWS_REGION)
+
+
+def handler(event, context):
+    """
+    Lambda entry point.
+
+    Event payload (from Step Functions):
+    {
+        "job_id": "uuid",
+        "source_key": "path/to/source.mp4",
+        "output_key": "output_filename.mp4",
+        "preset": {...} or null,
+        "trim_start": float or null,
+        "trim_end": float or null,
+        "duration": float or null,
+        "callback_url": "https://mpr.mcrn.ar/api",
+        "api_key": "secret"
+    }
+    """
+    job_id = event["job_id"]
+    source_key = event["source_key"]
+    output_key = event["output_key"]
+    preset = event.get("preset")
+    trim_start = event.get("trim_start")
+    trim_end = event.get("trim_end")
+    duration = event.get("duration")
+    callback_url = event.get("callback_url", "")
+    api_key = event.get("api_key", "")
+
+    logger.info(f"Starting job {job_id}: {source_key} -> {output_key}")
+
+    # Download source from S3
+    ext_in = Path(source_key).suffix or ".mp4"
+    tmp_source = tempfile.mktemp(suffix=ext_in, dir="/tmp")
+    logger.info(f"Downloading s3://{S3_BUCKET_IN}/{source_key}")
+    s3.download_file(S3_BUCKET_IN, source_key, tmp_source)
+
+    # Prepare output temp file
+    ext_out = Path(output_key).suffix or ".mp4"
+    tmp_output = tempfile.mktemp(suffix=ext_out, dir="/tmp")
+
+    try:
+        # Import ffmpeg module (bundled in container)
+        from core.ffmpeg.transcode import TranscodeConfig, transcode
+
+        if preset:
+            config = TranscodeConfig(
+                input_path=tmp_source,
+                output_path=tmp_output,
+                video_codec=preset.get("video_codec", "libx264"),
+                video_bitrate=preset.get("video_bitrate"),
+                video_crf=preset.get("video_crf"),
+                video_preset=preset.get("video_preset"),
+                resolution=preset.get("resolution"),
+                framerate=preset.get("framerate"),
+                audio_codec=preset.get("audio_codec", "aac"),
+                audio_bitrate=preset.get("audio_bitrate"),
+                audio_channels=preset.get("audio_channels"),
+                audio_samplerate=preset.get("audio_samplerate"),
+                container=preset.get("container", "mp4"),
+                extra_args=preset.get("extra_args", []),
+                trim_start=trim_start,
+                trim_end=trim_end,
+            )
+        else:
+            config = TranscodeConfig(
+                input_path=tmp_source,
+                output_path=tmp_output,
+                video_codec="copy",
+                audio_codec="copy",
+                trim_start=trim_start,
+                trim_end=trim_end,
+            )
+
+        success = transcode(config, duration=duration)
+
+        if not success:
+            raise RuntimeError("Transcode returned False")
+
+        # Upload result to S3
+        logger.info(f"Uploading s3://{S3_BUCKET_OUT}/{output_key}")
+        s3.upload_file(tmp_output, S3_BUCKET_OUT, output_key)
+
+        result = {"status": "completed", "job_id": job_id, "output_key": output_key}
+
+        # Callback to API
+        _callback(callback_url, job_id, api_key, {"status": "completed"})
+
+        return result
+
+    except Exception as e:
+        logger.exception(f"Job {job_id} failed: {e}")
+
+        _callback(callback_url, job_id, api_key, {
+            "status": "failed",
+            "error": str(e),
+        })
+
+        return {"status": "failed", "job_id": job_id, "error": str(e)}
+
+    finally:
+        for f in [tmp_source, tmp_output]:
+            try:
+                os.unlink(f)
+            except OSError:
+                pass
+
+
+def _callback(callback_url, job_id, api_key, payload):
+    """Call back to API with job result."""
+    if not callback_url:
+        return
+    try:
+        url = f"{callback_url}/jobs/{job_id}/callback"
+        headers = {}
+        if api_key:
+            headers["X-API-Key"] = api_key
+        resp = requests.post(url, json=payload, headers=headers, timeout=10)
+        logger.info(f"Callback response: {resp.status_code}")
+    except Exception as e:
+        logger.warning(f"Callback failed: {e}")