使用Api Gateway(Lambda函数)将图像上传到S3存储桶 [英] Upload Image into S3 bucket using Api Gateway, Lambda funnction

问题描述

我正在尝试从邮递员上传图像(base64)，我可以看到当我按下Serverless API时，在S3存储桶中添加了一些东西，但没有图像，我使用的是nodejs Lambda函数，因此我尝试了许多解决方案，但没有奏效.请向我建议我错了:

I'm trying to upload the image (base64) from the postman, I can see when I hit the Serverless API, something has been added in S3 bucket but not image, I'm using nodejs Lambda function, I tried so many solutions but that didn't work out. Please suggest me where I'm wrong:

const AWS = require('aws-sdk');
const s3 = new AWS.S3();
const moment = require('moment');
const fileType = require('file-type');
const sha1 = require('sha1');
const multipart = require('parse-multipart');

exports.handler = function (event, context, callback) {

    let request = event.body;

    // get the request
    let base64String = request.base64String;

    // pass the base64 string into a buffer
    let buffer = new Buffer(base64String, 'base64');

    let fileMime = fileType(buffer);

    // check if the base64 encoded string is a file
    if (fileMime === null) {
        return context.fail('The string supplied is not a file type');
    }

    let file = getFile(fileMime, buffer);
    // let file = getFile(fileMime, parts);
    let params = file.params;

    s3.upload(params, function (err, data) {
    // putObject(params, function (err, data) {
        if (err) {
            console.log(err);
            callback(err);
        }

        // if the file object is uploaded successfully to 
        // s3 then you can get your full url
        console.log('File URL', file.full_path + JSON.stringify(data));
        callback(null, data);

    });
}

let getFile = function (fileMime, buffer) {

    // get the file extension
    let fileExt = fileMime.ext;
    let hash = sha1(new Buffer(new Date().toString()));
    let now = moment().format('YYYY-MM-DD');

    let filePath = hash + '/';
    let fileName = now + '.' + fileExt;
    let fileFullName = filePath + fileName;
    let fileFullPath = 'https://console.aws.amazon.com/s3/buckets/bucket-name/images/' + fileFullName;

    console.log('fileFullPath' + fileFullPath);
    let params = {
        Bucket: 'bucket-name',
        Key: fileFullPath,
        // 'this is simply the filename and the extension, e.g fileFullName + fileExt',
        Body: buffer
    };

    let uploadFile = {
        size: buffer.toString('ascii').length,
        type: fileMime.mime,
        name: fileName,
        full_path: fileFullPath
    }

    return {
        'params': params,
        'uploadFile': uploadFile
    }
}

请让我知道，我在哪里缺少一些代码.将不胜感激.

Please let me know, where I'm missing some piece of codes. That will be appreciated.

推荐答案

将应在Web浏览器中打开的对象上传到S3时，需要设置正确的内容类型.当S3为您的对象提供服务时，您设置的内容类型将作为HTTP标头发送.

When uploading objects to S3 that should be opened in a web browser, you need to set the correct content type. When S3 serves your object, the content type you set will be sent as a HTTP header.

Web浏览器使用 MIME类型确定如何处理URL，而不是文件扩展名.

Web browsers use MIME types to determine how to process URLs, not file extensions.

在您的情况下，传递给s3.upload的参数中缺少内容类型.而且，密钥不正确.

In your case, the content type is missing from the parameters your are passing to s3.upload. Moreover, the key is incorrect.

应该是:

const params = {
  Bucket: 'bucket-name',
  Key: fileFullName // must be a path within your bucket and not an url like you have in fileFullPath,
  Body: buffer,
  ContentType: fileMime.mime // Sets the content type header, without this your browser cannot infer the type (browsers use mime types, not file extensions)
};

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