Xây dựng kiến trúc serverless cho hệ thống đăng ký sự kiện trên AWS

Giới thiệu

Trong bài viết này, mình xây dựng một hệ thống đăng ký sự kiện theo mô hình serverless trên AWS. Mục tiêu của hệ thống là cho phép người dùng điền form đăng ký trên giao diện web, sau đó backend sẽ tự động tiếp nhận dữ liệu, lưu trữ thông tin, gửi email xác nhận cho người đăng ký và đồng thời thông báo cho quản trị viên.

Điểm chính của mô hình này là không cần quản lý server truyền thống. Thay vào đó, các thành phần như giao diện, API, xử lý backend, lưu trữ dữ liệu và gửi thông báo đều được triển khai bằng các dịch vụ managed của AWS. Điều này giúp hệ thống dễ triển khai, dễ mở rộng và phù hợp với các bài toán như event registration, contact form hoặc lead collection.

Tổng quan kiến trúc

Hệ thống hoạt động theo các bước sau:

Người dùng truy cập giao diện web được deploy trên Amplify và điền form đăng ký gồm các thông tin như họ tên, email.
Khi người dùng bấm submit, frontend gửi request POST /register đến API Gateway.
API Gateway chuyển request đến để xử lý.

import osimport jsonimport uuidimport timeimport loggingfrom typing import Dict, Any, Optionalimport boto3from botocore.config import Configfrom botocore.exceptions import ClientError# ===== Env =====TABLE_NAME = os.getenv("TABLE_NAME") # e.g. d-dva-ddb-registrationQUEUE_URL = os.getenv("QUEUE_URL") # e.g. https://sqs.<region>.amazonaws.com/<acct>/d-dva-sqs-emailCORS_ORIGIN = os.getenv("CORS_ORIGIN", "*") # In production, set to specific domainif not TABLE_NAME or not QUEUE_URL: raise RuntimeError("Missing env vars: TABLE_NAME and/or QUEUE_URL")LOG_LEVEL = os.getenv("LOG_LEVEL", "INFO").upper()# ===== SDK clients (reuse) =====_cfg = Config( retries={"max_attempts": 5, "mode": "standard"}, read_timeout=3, connect_timeout=1, user_agent_extra="dva-registration/1.0")_sess = boto3.Session()_ddb = _sess.resource("dynamodb", config=_cfg)_table = _ddb.Table(TABLE_NAME)_sqs = _sess.client("sqs", config=_cfg)# ===== Logging =====logger = logging.getLogger()logger.setLevel(LOG_LEVEL)def create_response(status_code: int, body: Dict[str, Any], cors_origin: str = CORS_ORIGIN) -> Dict[str, Any]: """Create standardized API response with CORS headers""" return { "statusCode": status_code, "headers": { "Access-Control-Allow-Origin": cors_origin, "Access-Control-Allow-Headers": "Content-Type", "Access-Control-Allow-Methods": "OPTIONS,POST", "Content-Type": "application/json" }, "body": json.dumps(body) }def validate_input(body: Dict[str, Any]) -> Optional[str]: """Validate input fields, return error message if invalid""" required_fields = ["first_name", "last_name", "email"] # Check required fields for field in required_fields: if not body.get(field): return f"Missing required field: {field}" # Validate string fields if not isinstance(body[field], str): return f"Invalid type for {field}: must be string" # Trim and validate length value = body[field].strip() if not value: return f"Empty value for {field} not allowed" if field in ["first_name", "last_name"] and len(value) > 100: return f"{field} too long: max 100 characters" if field == "email": if len(value) > 254: return "Email too long: max 254 characters" if "@" not in value or "." not in value: return "Invalid email format" return Nonedef _parse_body(event: Dict[str, Any]) -> Dict[str, Any]: """Parse and decode request body""" try: if isinstance(event.get("body"), str): return json.loads(event["body"] or "{}") return event.get("body", {}) except json.JSONDecodeError: logger.error({"error": "invalid_json", "body": event.get("body")}) return {}def handle_options_request(event: Dict[str, Any]) -> Dict[str, Any]: """Handle OPTIONS request for CORS preflight""" return create_response(200, {"status": "ok"})def lambda_handler(event: Dict[str, Any], context: Any) -> Dict[str, Any]: """Main Lambda handler""" # Handle CORS preflight if event.get("httpMethod") == "OPTIONS": return handle_options_request(event) # Parse body body = _parse_body(event) if not body: return create_response(400, {"error": "Invalid request body"}) # Validate input error = validate_input(body) if error: return create_response(400, {"error": error}) # Prepare item item = { "id": str(uuid.uuid4()), "first_name": body["first_name"].strip(), "last_name": body["last_name"].strip(), "email": body["email"].strip().lower(), "status": "QUEUED", "created_at": int(time.time()), } # 1) Write to DynamoDB try: _table.put_item(Item=item) except ClientError as e: error_code = e.response.get("Error", {}).get("Code", "UNKNOWN") logger.error({ "step": "ddb_put_failed", "error_code": error_code, "message": str(e), "registration_id": item["id"] }) return create_response(500, {"error": "Database operation failed"}) except Exception as e: logger.error({ "step": "ddb_put_exception", "error": str(e), "registration_id": item["id"] }) return create_response(500, {"error": "Internal server error"}) # 2) Send message to SQS try: _sqs.send_message( QueueUrl=QUEUE_URL, MessageBody=json.dumps(item, ensure_ascii=False) ) except (ClientError, Exception) as e: logger.error({ "step": "sqs_send_failed", "error": str(e), "registration_id": item["id"] }) return create_response(500, {"error": "Message queue operation failed"}) logger.info({ "message": "registration_accepted", "registration_id": item["id"], "email": item["email"] }) return create_response(200, {"id": item["id"]})

import os, json, loggingimport boto3from botocore.config import Configfrom botocore.exceptions import ClientError# ==== Env ====TABLE_NAME = os.getenv("TABLE_NAME")TOPIC_ARN = os.getenv("TOPIC_ARN")SES_SENDER = os.getenv("SES_SENDER")LOG_LEVEL = os.getenv("LOG_LEVEL", "INFO").upper()if not (TABLE_NAME and TOPIC_ARN and SES_SENDER): raise RuntimeError("Missing env vars: TABLE_NAME / TOPIC_ARN / SES_SENDER")# ==== SDK clients (reuse) ====_cfg = Config(retries={"max_attempts": 5, "mode": "standard"}, read_timeout=5, connect_timeout=2, user_agent_extra="dva-sender/1.0")_sess = boto3.Session()_ddb = _sess.resource("dynamodb", config=_cfg)_table = _ddb.Table(TABLE_NAME)_sns = _sess.client("sns", config=_cfg)_ses = _sess.client("ses", config=_cfg)# ==== Logging ====logger = logging.getLogger()logger.setLevel(LOG_LEVEL)def lambda_handler(event, context): failures = [] # for SQS partial batch response for rec in event.get("Records", []): msg_id = rec.get("messageId") try: payload = json.loads(rec["body"]) rid = payload.get("id") email = payload.get("email") first = payload.get("first_name", "") last = payload.get("last_name", "") # 1) Send email to user via SES _ses.send_email( Source=SES_SENDER, Destination={"ToAddresses": [email]}, Message={ "Subject": {"Data": "Registration confirmed"}, "Body": {"Text": {"Data": f"Hi {first} {last},\nThanks for registering!"}} } ) # 2) Notify admin via SNS _sns.publish( TopicArn=TOPIC_ARN, Subject="New registration", Message=json.dumps( {"id": rid, "email": email, "first_name": first, "last_name": last}, ensure_ascii=False ) ) # 3) Update DynamoDB status -> SENT if rid: _table.update_item( Key={"id": rid}, UpdateExpression="SET #s = :v", ExpressionAttributeNames={"#s": "status"}, ExpressionAttributeValues={":v": "SENT"} ) logger.info({"msg": "sender_processed", "id": rid, "messageId": msg_id}) except ClientError as e: # Mark this record as failed -> only this one will be retried (partial batch) logger.error({ "msg": "aws_client_error", "messageId": msg_id, "code": e.response.get("Error", {}).get("Code"), "detail": e.response.get("Error", {}).get("Message") }) failures.append({"itemIdentifier": msg_id}) except Exception as e: logger.exception({"msg": "unhandled", "messageId": msg_id}) failures.append({"itemIdentifier": msg_id}) # Partial batch response for SQS (prevents reprocessing successful records) if failures: return {"batchItemFailures": failures} return {"statusCode": 200}

<!doctype html><html lang="en"><head> <meta charset="utf-8" /> <title>Event Registration</title> <meta name="viewport" content="width=device-width, initial-scale=1" /> <style> :root { color-scheme: dark; } * { box-sizing: border-box; } html, body { margin:0; padding:0; background:#0b1020; color:#e9edf5; font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial; } .wrap { max-width:980px; margin:48px auto; padding:0 24px; } .card { background:#0f1b33; border:1px solid #1d2a4d; border-radius:16px; padding:28px; box-shadow:0 6px 30px rgba(0,0,0,.35); } h1 { margin:0 0 12px; font-size:28px; font-weight:800; } .muted { color:#b6c2df; margin-bottom:18px; } label { display:block; font-weight:700; margin:16px 0 8px; } .req { color:#ff5a7a; margin-left:4px; } input { width:100%; background:#0a1429; color:#eef3ff; border:1px solid #223055; border-radius:8px; padding:12px 14px; outline:0; transition:border .15s; } input:focus { border-color:#6ea8ff; box-shadow:0 0 0 3px rgba(110,168,255,.2); } input.err { border-color:#e66; box-shadow:0 0 0 3px rgba(230,102,102,.15); } .counter { font-size:12px; color:#8ea0c9; margin-top:6px; } .errText { color:#ffb8c7; font-size:12px; margin-top:6px; } .btn { margin-top:18px; background:linear-gradient(90deg,#6a5cff,#7f38ff); border:none; color:#fff; padding:12px 18px; font-weight:700; border-radius:10px; cursor:pointer; } .btn[disabled]{opacity:.6; cursor:not-allowed;} .alert { margin-top:16px; padding:12px 14px; border-radius:8px; } .ok { background:#10361f; color:#b8f5cf; border:1px solid #1e6d3d; } .err { background:#3a1520; color:#ffd2df; border:1px solid #7b2c41; } .note { margin-top:22px; line-height:1.6; color:#cbd6f3; } a { color:#8ab4ff; text-decoration:none; } a:hover{text-decoration:underline;} </style></head><body> <div class="wrap"> <div class="card"> <h1>Contact information</h1> <p class="muted"> This name will be printed on your badge. Your legal name, if different, can be provided in the event profile. </p> <form id="form" novalidate> <label>First name <span class="req">*</span></label> <input id="first" maxlength="100" aria-required="true" /> <div class="counter" id="c-first">0/100</div> <div class="errText" id="e-first" hidden></div> <label>Last name <span class="req">*</span></label> <input id="last" maxlength="100" aria-required="true" /> <div class="counter" id="c-last">0/100</div> <div class="errText" id="e-last" hidden></div> <label>Email <span class="req">*</span></label> <input id="email" type="email" maxlength="254" aria-required="true" /> <div class="counter" id="c-email">0/254</div> <div class="errText" id="e-email" hidden></div> <button class="btn" id="submit" type="submit">Continue</button> <div id="alert-ok" class="alert ok" hidden></div> <div id="alert-err" class="alert err" hidden></div> </form> <div class="note"> <h3 style="margin:18px 0 8px">AWS Event Terms</h3> <p> AWS takes reports of misconduct seriously and encourages event participants to report disruptive or otherwise unsafe behavior. Attendees who do not comply with the <a href="https://aws.amazon.com/codeofconduct/" target="_blank" rel="noreferrer">AWS Code of Conduct</a> may be required to leave all event venues and will be banned from future participation. </p> <p> By clicking Continue, you agree to the AWS Event Terms & Conditions and the AWS Code of Conduct. Your information will be handled in accordance with the AWS Privacy Notice. </p> </div> </div> </div> <script> const API_URL = "%%API_URL%%"; const NAME_MAX = 100, EMAIL_MAX = 254; const emailRe = /^[^\s@]+@[^\s@]+\.[^\s@]+$/; const $ = (id) => document.getElementById(id); const first = $("first"), last = $("last"), email = $("email"); const cFirst = $("c-first"), cLast = $("c-last"), cEmail = $("c-email"); const eFirst = $("e-first"), eLast = $("e-last"), eEmail = $("e-email"); const btn = $("submit"), ok = $("alert-ok"), err = $("alert-err"); function setErr(input, el, msg) { if (msg) { input.classList.add("err"); el.textContent = msg; el.hidden = false; } else { input.classList.remove("err"); el.hidden = true; el.textContent = ""; } } function count(el, counter, max) { const n = el.value.trim().length; counter.textContent = `${n}/${max}`; } function validate() { const f = first.value.trim(); const l = last.value.trim(); const m = email.value.trim(); let ok = true; // first_name if (!f) { setErr(first, eFirst, "First name is required"); ok = false; } else if (f.length > NAME_MAX) { setErr(first, eFirst, `Max ${NAME_MAX} characters`); ok = false; } else setErr(first, eFirst, ""); // last_name if (!l) { setErr(last, eLast, "Last name is required"); ok = false; } else if (l.length > NAME_MAX) { setErr(last, eLast, `Max ${NAME_MAX} characters`); ok = false; } else setErr(last, eLast, ""); // email if (!m) { setErr(email, eEmail, "Email is required"); ok = false; } else if (m.length > EMAIL_MAX) { setErr(email, eEmail, `Max ${EMAIL_MAX} characters`); ok = false; } else if (!emailRe.test(m)) { setErr(email, eEmail, "Email format is invalid"); ok = false; } else setErr(email, eEmail, ""); return ok; } ["input","blur"].forEach(ev => { first.addEventListener(ev, () => count(first, cFirst, NAME_MAX)); last.addEventListener(ev, () => count(last, cLast, NAME_MAX)); email.addEventListener(ev, () => count(email, cEmail, EMAIL_MAX)); }); count(first, cFirst, NAME_MAX); count(last, cLast, NAME_MAX); count(email, cEmail, EMAIL_MAX); document.getElementById("form").addEventListener("submit", async (e) => { e.preventDefault(); ok.hidden = true; ok.textContent = ""; err.hidden = true; err.textContent = ""; if (!validate()) return; btn.disabled = true; btn.textContent = "Submitting…"; try { const res = await fetch(API_URL, { method: "POST", headers: { "Content-Type": "application/json", }, body: JSON.stringify({ first_name: first.value.trim(), last_name: last.value.trim(), email: email.value.trim().toLowerCase() }) }); if (!res.ok) { const t = await res.text(); throw new Error(`API ${res.status}: ${t || "request failed"}`); } const data = await res.json().catch(() => ({})); ok.textContent = `Thanks! Your registration id is ${data.id || "(created)"}.Please check your email!!`; ok.hidden = false; first.value = ""; last.value = ""; email.value = ""; [first,last,email].forEach((el)=>el.classList.remove("err")); [cFirst,cLast,cEmail].forEach((c)=>c.textContent="0/0"); // will reset by count() count(first, cFirst, NAME_MAX); count(last, cLast, NAME_MAX); count(email, cEmail, EMAIL_MAX); } catch (ex) { err.textContent = ex.message || "Submit failed"; err.hidden = false; } finally { btn.disabled = false; btn.textContent = "Continue"; } }); </script></body></html>