AWS Lambda 在放置 s3 对象时出错

Question

我正在开发一个功能，当任何图像上传到存储桶中的图像文件夹时，通过在屏幕截图文件夹中保存图像的缩略图版本来创建缩略图。我正在使用无服务器框架。我不断收到如下所示的错误。我粘贴了准确的代码，因此任何人都可以复制粘贴并实施此解决方案。 Serverless.yml，处理函数文件以及任何支持文件也包括在内。

我不明白当我指的是缓冲区时，为什么会出现对象类型不是缓冲区等错误

 { InvalidParameterType: Expected params.Body to be a string, Buffer, Stream, Blob, or typed array object
at ParamValidator.fail (/var/runtime/node_modules/aws-sdk/lib/param_validator.js:50:37)
at ParamValidator.validatePayload (/var/runtime/node_modules/aws-sdk/lib/param_validator.js:255:10)
at ParamValidator.validateScalar (/var/runtime/node_modules/aws-sdk/lib/param_validator.js:133:21)
at ParamValidator.validateMember (/var/runtime/node_modules/aws-sdk/lib/param_validator.js:94:21)
at ParamValidator.validateStructure (/var/runtime/node_modules/aws-sdk/lib/param_validator.js:75:14)
at ParamValidator.validateMember (/var/runtime/node_modules/aws-sdk/lib/param_validator.js:88:21)
at ParamValidator.validate (/var/runtime/node_modules/aws-sdk/lib/param_validator.js:34:10)
at Request.VALIDATE_PARAMETERS (/var/runtime/node_modules/aws-sdk/lib/event_listeners.js:125:42)
at Request.callListeners (/var/runtime/node_modules/aws-sdk/lib/sequential_executor.js:105:20)
at callNextListener (/var/runtime/node_modules/aws-sdk/lib/sequential_executor.js:95:12)
message: 'Expected params.Body to be a string, Buffer, Stream, Blob, or typed array object',
code: 'InvalidParameterType',
time: 2019-03-12T16:37:26.910Z }

代码：

Handler.js

'use strict';

const resizer = require('./resizer');

module.exports.resizer = (event, context, callback) => {
 console.log(event.Records[0].s3);

 const bucket = event.Records[0].s3.bucket.name;
 const key = event.Records[0].s3.object.key;

 console.log(`A file named ${key} was put in a bucket ${bucket}`);

 resizer(bucket, key)
  .then(() => {
   console.log(`The thumbnail was created`);
   callback(null, {
    message: 'The thumbnail was created'
   });
  })
  .catch(error => {
   console.log(error);
   callback(error);
  });
};

module.exports.thumbnails = (event, context, callback) => {
 const bucket = event.Records[0].s3.bucket.name;
 const key = event.Records[0].s3.object.key;

 console.log(bucket);
 console.log(key);

 console.log(`A new file ${key} was created in the bucket ${bucket}`);
 callback(null, {
  message: `A new file ${key} was created in the bucket ${bucket}`
 });
};

Resizer.js

'use strict';

const AWS = require('aws-sdk');
const S3 = new AWS.S3();
const Jimp = require('jimp'); //https://github.com/oliver-moran/jimp

module.exports = (bucket, key) => {
 const newKey = replacePrefix(key);
 const height = 512;

 return getS3Object(bucket, key).then(data => resizer(data.Body, height)).then(buffer => putS3Object(bucket, newKey, buffer));
};

function getS3Object(bucket, key) {
 return S3.getObject({
  Bucket: bucket,
  Key: key
 }).promise();
}

function putS3Object(bucket, key, body) {
 return S3.putObject({
  Body: body,
  Bucket: bucket,
  ContentType: 'image/jpg',
  Key: key
 }).promise();
}

function replacePrefix(key) {
 const uploadPrefix = 'uploads/';
 const thumbnailsPrefix = 'thumbnails/';
 return key.replace(uploadPrefix, thumbnailsPrefix);
}

function resizer(data, height) {
 return Jimp.read(data)
  .then(image => {
   return image
    .resize(Jimp.AUTO, height)
    .quality(100) // set JPEG quality
    .getBuffer(Jimp.MIME_JPEG, (err, buffer) => {
     return buffer;
    });
  })
  .catch(err => err);
}

Serverless.yml

service: serverless-resizer-project # NOTE: update this with your service name


provider:
  name: aws
  runtime: nodejs6.10
  profile: student1

  iamRoleStatements:
    - Effect: "Allow"
      Action:
        - "s3:ListBucket"
        - "s3:GetObject"
        - "s3:PutObject"
      Resource: "arn:aws:s3:::serverless-resizer-project-images/*"

functions:
  resizer:
    handler: handler.resizer
    events:
      - s3:
          bucket: serverless-resizer-project-images
          event: s3:ObjectCreated:*
          rules:
            - prefix: uploads/
            - suffix: .jpg
 thumbnails:
    handler: handler.thumbnails
    events:
      - s3:
          bucket: serverless-resizer-project-images
          event: s3:ObjectCreated:*
          rules:
            - prefix: thumbnails/
            - suffix: .jpg

Answer 1

您的 resizer 函数的 return 值不是您所期望的。您正在使用带有回调的 getBuffer 函数，这意味着图像的缓冲区不是由承诺解析的，而是在回调中使用的，这不是您的意图。您应该改为使用 getBufferAsync，它 return 是解析为图像缓冲区的承诺。您的 resizer 函数应如下所示：

function resizer(data, height) {
    return Jimp.read(data)
        .then(image => image
                .resize(Jimp.AUTO, height)
                .quality(100) // set JPEG quality
                .getBufferAsync(Jimp.MIME_JPEG)
        )
        .catch(err => err);
}

AWS Lambda 在放置 s3 对象时出错

AWS Lambda gives error on putting s3 object

amazon-s3

node.js

aws-sdk

aws-lambda

serverless