survey-extraction/deployment/lambda/lambda_example/docker/app.py

import os
import json
import time
import requests


# ============================================================
# CONFIG
# ============================================================

API_BASE = "https://api.dev.hestia.homes/v1/tasks/"  # e.g. https://api.myserver.com/tasks
API_TOKEN = "4QPwbB6hEdUloDVtbBJCUTfGBdBgWwpeavWQ7t5Z"


# ============================================================
# Low-level API wrapper
# ============================================================

def api(method, path, body=None):
    """Generic function to call your backend Task API."""
    url = f"{API_BASE}{path}"

    headers = {
        "Authorization": f"Bearer {API_TOKEN}",
        "Content-Type": "application/json",
    }

    print(f"[API] {method} {url}")
    if body:
        print(f"[API] Payload: {json.dumps(body)}")

    response = requests.request(
        method,
        url,
        headers=headers,
        data=json.dumps(body) if body else None
    )

    print(f"[API] Response: {response.status_code}")

    if response.status_code >= 400:
        print(f"[API ERROR] {response.text}")
        raise Exception(f"API Error {response.status_code}: {response.text}")

    return response.json()


# ============================================================
# CloudWatch Logs URL generator (with time range)
# ============================================================

def build_cloudwatch_url(context, start_ms, end_ms):
    region = context.invoked_function_arn.split(":")[3]
    log_group = context.log_group_name
    log_stream = context.log_stream_name

    log_group_enc = log_group.replace("/", "$252F")
    log_stream_enc = log_stream.replace("/", "$252F")

    return (
        f"https://{region}.console.aws.amazon.com/cloudwatch/home"
        f"?region={region}#logsV2:log-groups/log-group/{log_group_enc}"
        f"/log-events/{log_stream_enc}"
        f"$3Fstart$3D{start_ms}$26end$3D{end_ms}"
    )


# ============================================================
# Subtask lifecycle action helpers
# ============================================================

def mark_in_progress(subtask_id):
    print(f"[SUBTASK] Marking {subtask_id} as IN PROGRESS")
    return api("PUT", f"/subtasks/{subtask_id}/status", {"status": "in progress"})


def mark_complete(subtask_id, outputs, cloud_logs):
    print(f"[SUBTASK] Marking {subtask_id} as COMPLETE")
    return api("POST", f"/subtasks/{subtask_id}/finalize", {
        "status": "complete",
        "outputs": outputs,
        "cloud_logs_url": cloud_logs
    })


def mark_failed(subtask_id, error_message, cloud_logs):
    print(f"[SUBTASK] Marking {subtask_id} as FAILED")
    return api("POST", f"/subtasks/{subtask_id}/finalize", {
        "status": "failed",
        "outputs": {"error": error_message},
        "cloud_logs_url": cloud_logs
    })


# ============================================================
# Lambda Handler
# ============================================================

def handler(event, context):
    """
    Example Lambda that:
    - marks subtask in progress
    - prints simulated work steps
    - marks complete or failed
    - attaches CloudWatch Log URL
    """

    subtask_id = event["subtask_id"]

    print("=====================================")
    print(" 🚀 LAMBDA INVOCATION STARTED")
    print(f" 🧩 Subtask ID: {subtask_id}")
    print("=====================================")

    start_ms = int(time.time() * 1000)

    try:
        # ---- Step 1: Mark subtask IN PROGRESS ----
        mark_in_progress(subtask_id)

        print("\n---- Simulating Work ----")

        print("Step 1: Loading resources...")
        time.sleep(0.5)

        print("Step 2: Calling an external service...")
        time.sleep(0.7)

        print("Step 3: Processing data...")
        time.sleep(1.0)

        # UNCOMMENT TO TEST FAILURE
        # raise Exception("Simulated failure for testing")

        print("Step 4: Finalizing outputs...")
        time.sleep(0.5)

        outputs = {
            "result": "success",
            "calculated_value": 123,
            "details": "This is example output from the handler.",
            "input_params": event.get("params", {})
        }

        print("Work completed successfully.")

        end_ms = int(time.time() * 1000)
        cloud_logs_url = build_cloudwatch_url(context, start_ms, end_ms)

        print(f"Generated CloudWatch URL:\n{cloud_logs_url}\n")

        # ---- Step 2: Mark COMPLETE ----
        mark_complete(subtask_id, outputs, cloud_logs_url)

        print("=====================================")
        print(" ✅ LAMBDA EXECUTION COMPLETE")
        print("=====================================")

        return {
            "statusCode": 200,
            "body": outputs,
            "cloudwatch_logs": cloud_logs_url
        }

    except Exception as e:
        print("=====================================")
        print(" ❌ ERROR IN LAMBDA EXECUTION")
        print("=====================================")
        print(f"Error: {e}")

        end_ms = int(time.time() * 1000)
        cloud_logs_url = build_cloudwatch_url(context, start_ms, end_ms)

        # ---- Step 3: Mark FAILED ----
        mark_failed(subtask_id, str(e), cloud_logs_url)

        return {
            "statusCode": 500,
            "error": str(e),
            "cloudwatch_logs": cloud_logs_url
        }