6minutes aws lambda for dummy

Author: misostack

content/post/6minutes-tech-aws-lambda-for-dummy.md

@@ -0,0 +1,199 @@
+---
+title: "6minutes Tech Aws Lambda for Dummy"
+type: "post"
+date: 2025-10-14T20:17:17+07:00
+description: "In this topic, you will learn the main concept about AWS Lambda, develop locally and deploy to production"
+keywords: ["6minutes Tech Aws Lambda for Dummy"]
+keywords: ["Dependency Injection and Ioc"]
+categories: ["cheatsheet", "6minutes-tech"]
+tags: []
+image: /articles/6minutes/002.png
+---
+
+## What is AWS Lambda
+
+AWS Lambda is a **compute service** that **runs code** _without the need to manage servers_. Your code **runs**, **scaling** up and down **automatically**, with **pay-per-use** _pricing_
+
+### Write your first function
+
+![Lambda service](/articles/6minutes/aws-lambda/001.png)
+
+Let's start by creating a function from a blueprint to see the structure and required materials to allow a lambda function can run. Later, we'll analyze more details.
+
+![Lambda blueprint function](/articles/6minutes/aws-lambda/002.png)
+
+After creating a lambda function, AWS already suggested us to setup locally.
+Let's ignore it, we are going to see the code first and how to run it.
+
+Links :
+
+- vscode://AmazonWebServices.aws-toolkit-vscode/lambda/load-function?functionName=helloFromNextJSVietnam&region=us-east-1&isCfn=false&userType=iam-user
+- https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_access-keys.html
+
+![Lambda blueprint function](/articles/6minutes/aws-lambda/003.png)
+
+What we can see in the code is a function that receive an event and its context
+
+![Lambda event handler](/articles/6minutes/aws-lambda/004.png)
+
+Let's create an event and invoke it to see what's happened next
+
+![Lambda event ](/articles/6minutes/aws-lambda/005.png)
+
+Event Name has limitation of length: Maximum of 25 characters
+
+![Lambda event ](/articles/6minutes/aws-lambda/006.png)
+
+Event has been invoked, now you can see
+
+![Lambda event ](/articles/6minutes/aws-lambda/007.png)
+
+We must update the code a little bit
+
+```js
+console.log("Loading function");
+
+export const handler = async (event, context) => {
+  //console.log('Received event:', JSON.stringify(event, null, 2));
+  console.log(context);
+  console.log(event);
+  console.log("name =", event.name, typeof event.name);
+  console.log("website =", event.website, typeof event.website);
+  console.log("number =", event.number, typeof event.number);
+  console.log("aBoolean =", event.aBoolean, typeof event.aBoolean);
+  return {
+    name: event.name,
+    website: event.website,
+    number: event.number,
+    aBoolean: event.aBoolean,
+  };
+  // throw new Error('Something went wrong');
+};
+```
+
+To test the changes, you must deploy
+
+![Lambda event ](/articles/6minutes/aws-lambda/008.png)
+
+Let's explore
+
+![Lambda event ](/articles/6minutes/aws-lambda/009.png)
+
+![Lambda event ](/articles/6minutes/aws-lambda/010.png)
+
+### Some interesting tests
+
+Default timeout is 3 seconds
+
+![Lambda event ](/articles/6minutes/aws-lambda/011.png)
+
+Lambda runs your code for a set amount of time before timing out. Timeout is the maximum amount of time in seconds that a Lambda function can run. The default value for this setting is 3 seconds, but you can adjust this in increments of 1 second up to a maximum value of 900 seconds (15 minutes).
+
+Let's change it
+
+![Lambda event ](/articles/6minutes/aws-lambda/012.png)
+
+![Lambda event ](/articles/6minutes/aws-lambda/013.png)
+
+And try again
+
+So now you can see, the execution time limit is 60 seconds, and when lambda function run, it will check every seconds, with our sample code, here is the final output
+
+```js
+console.log("Loading function");
+
+export const handler = async (event, context) => {
+  console.log("Remaining Time", context.getRemainingTimeInMillis() / 1000);
+  await new Promise((resolve) => setTimeout(resolve, 5000));
+  //console.log('Received event:', JSON.stringify(event, null, 2));
+  console.log("Remaining Time", context.getRemainingTimeInMillis() / 1000);
+  await new Promise((resolve) => setTimeout(resolve, 5000));
+  console.log(context);
+  console.log(event);
+  console.log("name =", event.name, typeof event.name);
+  console.log("website =", event.website, typeof event.website);
+  console.log("number =", event.number, typeof event.number);
+  console.log("aBoolean =", event.aBoolean, typeof event.aBoolean);
+  console.log("Remaining Time", context.getRemainingTimeInMillis() / 1000);
+  return {
+    name: event.name,
+    website: event.website,
+    number: event.number,
+    aBoolean: event.aBoolean,
+    remainingTime: context.getRemainingTimeInMillis() / 1000,
+  };
+  // throw new Error('Something went wrong');
+};
+```
+
+![Lambda event ](/articles/6minutes/aws-lambda/015.png)
+
+Let's make the function public so we can test with http request or postman
+
+![Lambda event ](/articles/6minutes/aws-lambda/016.png)
+
+![Lambda event ](/articles/6minutes/aws-lambda/017.png)
+
+And you have
+
+![Lambda event ](/articles/6minutes/aws-lambda/018.png)
+
+It can trigger but
+
+![Lambda event ](/articles/6minutes/aws-lambda/019.png)
+
+Let's change
+
+```js
+console.log("Loading function");
+
+export const handler = async (event, context) => {
+  // ---- parse JSON body safely (Function URL / API GW v2) ----
+  const isB64 = event?.isBase64Encoded;
+
+  const raw =
+    typeof event?.body === "string"
+      ? isB64
+        ? Buffer.from(event.body, "base64").toString("utf8")
+        : event.body
+      : null;
+
+  let data = {};
+  if (raw) {
+    try {
+      data = JSON.parse(raw);
+    } catch {
+      data = {};
+    }
+  } else if (event && typeof event === "object") {
+    // fallback for Lambda Console tests (where event is already an object)
+    data = event;
+  }
+
+  // ---- read your fields from parsed body ----
+  const { name, website, number, aBoolean } = data;
+
+  // ---- return a proper HTTP response for Function URLs ----
+  return {
+    statusCode: 200,
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify({
+      name,
+      website,
+      number,
+      aBoolean,
+      remainingTime: context.getRemainingTimeInMillis() / 1000,
+    }),
+    isBase64Encoded: false,
+  };
+};
+```
+
+![Lambda event ](/articles/6minutes/aws-lambda/020.png)
+
+Let's finish the topic right there. Next time we're going to develop locally, run test and deploy a small script with node modules as well.
+
+## References
+
+- https://docs.aws.amazon.com/lambda/latest/dg/concepts-basics.html
+- https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/what-is-sam-overview.html