如何在nodejs中生成aws s3簽名

Question

我一直在嘗試生成預簽名的 url 以使用普通的 javascript 上傳我的對象，但我經常收到 signaturedoesn'tmatch 錯誤。 如果有人可以幫助我，那將是很大的幫助。

      const myBucket = "my-bucket-name";
      const accessKey = "myaccesskey";
      const secretAccessKey = "mysecretkey";
      const regionName = "us-east-1";
      const myKey = "codeTest.jpg";
      const serviceName = "s3upload";
      const signedUrlExpireSeconds = 60 * 5; // In 5 minutes

      const ep = new AWS.Endpoint("s3.wasabisys.com");
      const s3 = new AWS.S3({
        accessKeyId: accessKey,
        secretAccessKey: secretAccessKey,
        bucket: myBucket,
        signatureVersion: "v4",
        region: regionName,
        endpoint: ep
      });
      const signedUrl = s3.getSignedUrl("putObject", {
            Bucket: myBucket,
            Key: myKey,
            ACL: "public-read",         
            Expires: signedUrlExpireSeconds,
      });

Answer 1

Function 創建 Presigned url 到PutObject到 S3。 這是來自 nodejs/express 服務器。

Function createPresignedPost

    const S3 = require('aws-sdk/clients/s3');        
    const s3 = new S3(); //or new S3(config.aws.access), if you want to pass credentials

    module.exports.createPresignedPost = async function(remoteFile, expireSeconds = 180) {
        const params = {
            Bucket: S3_BUCKET_NAME,
            Fields: {
                key: remoteFile //This is S3 file name, where it will get uploaded
            },
            Expires: expireSeconds,
            Conditions: [
                {'acl': 'private'},
                ["content-length-range", 0, 20971520],      //20 MB
                ["starts-with", "$Content-Type", "image/"]  //only images
           ]
        };

        return new Promise((resolve, reject) => {
            s3.createPresignedPost(params, (err, data) => {
                if(err) {
                    return reject(err);
                }
            
                resolve(data);
            });
        })
    }

如果你使用這個 function 作為

const signed = await createPresignedPost("uploaded/file");

const body = {
    upload_url: signed.url,
    upload_fields: Object.assign({acl: 'private'}, signed.fields)
};
return res.status(ht.C.OK).send({success: true, data: body});

和@客戶端，

ApiService.imagePost(item._id).then(response =>  {
      signed = response.data.data;
      const formData = new FormData();
      if (files.length > 0) {
          for(const field in signed.upload_fields) {
              formData.append(field, signed.upload_fields[field]);
          }
          formData.append("Content-Type",files[0].type);
          formData.append("file",files[0]);
                
          return ApiService.file.upload(signed.upload_url, formData);
      }
}