Build API Gateway with Lambda Integration connect DynamoDB

Lab Details

You will practice using Amazon API Gateway, Lambda and DynamoDB.
Duration: 20 minutes
AWS Region: US East (N. Virginia) us-east-1

Architecture Diagram

Task Details

Create dynamodb table
Create lambda
- Tạo role cho lambda access đến dynamo db
- Tạo lambda create user
- Tạo lambda get user
Create api gateway
- Tạo resource: user
- Tạo method POST cho resource user
- Tạo method GET cho resource user
- Deploy API lên dev stage
Test API

Create DynamoDB Table

Table name: d-saa-dynamodb
Partition Key: PK
Sort Key: để trống
Table settings: Chọn Default settings

Create Lambda

Create role cho lambda có quyền access đến DynamoDB

Create Role với các parameter sau:

Use case: Lambda
Policy:
- AmazonDynamoDBFullAccess
- AWSLambdaBasicExecutionRole
Role name: d-saa-lambda-role

Kết quả:

Create Lambda function: create-user

Tại Console Lambda -> Functions -> Create function

Author from scratch
Basic information
- Function name: d-saa-lambda-create-user
- Runtime: Python 3.xx
- Architecture: arm64
- Change default execution role
  - Use an existing role: Select d-saa-lambda-role

Update source code cho lambda

import boto3
import uuid
import json

dynamodb = boto3.resource('dynamodb')
table = dynamodb.Table('d-saa-dynamodb')  

def lambda_handler(event, context):
    strBody = event.get('body')
    param = json.loads(strBody)
    name = param['name']
    pk = f"USER#{str(uuid.uuid4())}"

    item = {
        'PK': pk,
        'Name': name
    }

    table.put_item(Item=item)

    response = {
        'statusCode': 200,
        'body': f"Data saved with PK: {pk}"
    }

    return response

Nhấn Deploy

Create Lambda function: get-user

Tương tự tạo function thứ 2:

Vào Lambda Console > Functions > Create Function

Author from scratch
Basic information
- Function name: d-saa-lambda-get-user
- Runtime: Python 3.xx
- Architecture: arm64
- Change default execution role
  - Use an existing role: Select d-saa-lambda-role

Update source code cho lambda

import boto3
import json 

dynamodb = boto3.resource('dynamodb')
table = dynamodb.Table('d-saa-dynamodb')  

def lambda_handler(event, context):
    response = table.scan()

    items = response['Items']
    while 'LastEvaluatedKey' in response:
        response = table.scan(ExclusiveStartKey=response['LastEvaluatedKey'])
        items.extend(response['Items'])

    records = []
    for item in items:
        pk = item['PK']
        name = item['Name']
        record = {'PK': pk, 'Name': name}
        records.append(record)
    
    response = {
        'statusCode': 200,
        'body': json.dumps(records)
    }

    return response