{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": [
                "s3:PutObject",
                "s3:GetObject"
            ],
            "Resource": "arn:aws:s3:::{버킷이름}/*"
        }
    ]
}

// dependencies
const AWS = require('aws-sdk');
const util = require('util');
const sharp = require('sharp');
                     
// get reference to S3 client
const s3 = new AWS.S3();
                     
exports.handler = async (event, context, callback) => {
                     
// Read options from the event parameter.
console.log("Reading options from event:\n", util.inspect(event, {depth: 5}));
const srcBucket = event.Records[0].s3.bucket.name;
// Object key may have spaces or unicode non-ASCII characters.
const srcKey    = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, " "));
const dstBucket = {사용할 버킷명};
const dstKey    = {파일 이름}; // 리사이징 된 이미지가 저장될 파일 이름. 폴더를 사용한다면 폴더명도 추가해준다 ex."{폴더명}/" + fileName; 

// Infer the image type from the file suffix.
const typeMatch = srcKey.match(/\.([^.]*)$/);
if (!typeMatch) {
  console.log("Could not determine the image type.");
  return;
}
                     
// Check that the image type is supported
const imageType = typeMatch[1].toLowerCase();
if (imageType != "jpg" && imageType != "png") {
  console.log(`Unsupported image type: ${imageType}`);
  return;
}
                     
// srcBucket에 업로드된 이미지를 가져온다
try {
  const params = {
    Bucket: srcBucket,
    Key: srcKey
  };
  var origimage = await s3.getObject(params).promise();
                     
} catch (error) {
  console.log(error);
  return;
}
                     
// set thumbnail width. Resize will set the height automatically to maintain aspect ratio.
const width  = 200;
                     
// Use the sharp module to resize the image and save in a buffer.
try {
  var buffer = await sharp(origimage.Body).resize(width).toBuffer();
                     
} catch (error) {
  console.log(error);
  return;
}
                     
// 다시 dstBucket, dstKey에 지정한 경로로 업로드를 진행한다
try {
  const destparams = {
    Bucket: dstBucket,
    Key: dstKey,
    Body: buffer,
    ContentType: "image"
  };
                     
  const putResult = await s3.putObject(destparams).promise();
                     
  } catch (error) {
    console.log(error);
    return;
  }
                     
  console.log('Successfully resized ' + srcBucket + '/' + srcKey +
    ' and uploaded to ' + dstBucket + '/' + dstKey);
  };

{
  "name": "lambda-s3-trigger",
  "version": "1.0.0",
  "description": "Lambda 이미지 리사이징",
  "main": "index.js",
  "author": "inpa",
  "license": "ISC",
  "dependencies": {
    "aws-sdk": "^2.1299.0",
    "sharp": "^0.31.3"
  }
}

zip -r nodejs nodejs

rm -rf node_modules/sharp
npm install –arch=x64 –platform=linux –target=16x sharp

{
  "Records": [
    {
      "eventVersion": "2.0",
      "eventSource": "aws:s3",
      "awsRegion": {Region 명},
      "eventTime": "2023-01-21T00:00:00.000Z",
      "eventName": "ObjectCreated:Put",
      "userIdentity": {
        "principalId": "test001"
      },
      "requestParameters": {
        "sourceIPAddress": "127.0.0.1"
      },
      "responseElements": {
        "x-amz-request-id": "~~~",
        "x-amz-id-2": "~~~"
      },
      "s3": {
        "s3SchemaVersion": "1.0",
        "configurationId": "~~~",
        "bucket": {
          "name": {버킷명},
          "ownerIdentity": {
            "principalId": "test001"
          },
          "arn": {버킷_arn}
        },
        "object": {
          "key": {테스트할 파일명},
          "size": "6767104",
          "eTag": "~~~",
          "sequencer": "~~~"
        }
      }
    }
  ]
}