如何使用AWS SDK for Node.js将Amazon S3中的所有对象从一个前缀复制/移动到另一个前缀

Question

如何将所有对象从一个前缀复制到另一个前缀？我已经尝试了所有可能的方法将一个镜头中的所有对象从一个前缀复制到另一个前缀,但似乎工作的唯一方法是循环遍历对象列表并逐个复制它们.这实在是效率低下.如果我在一个文件夹中有数百个文件,我是否必须拨打100个电话？

var params = {
         Bucket: bucket,
         CopySource: bucket+'/'+oldDirName+'/filename.txt',
         Key: newDirName+'/filename.txt',
 };
s3.copyObject(params, function(err, data) {
  if (err) {
      callback.apply(this, [{
          type: "error",
          message: "Error while renaming Directory",
          data: err
      }]);
  } else {
      callback.apply(this, [{
          type: "success",
          message: "Directory renamed successfully",
          data: data
      }]);
  }
});

Answer 1

您需要创建一个AWS.S3.listObjects()列出具有特定前缀的对象.但是你是正确的,因为你需要为每个要从一个存储桶/前缀复制到相同或另一个存储桶/前缀的对象进行一次调用.

您还可以使用async等实用程序库来管理您的请求.

var AWS = require('aws-sdk');
var async = require('async');
var bucketName = 'foo';
var oldPrefix = 'abc/';
var newPrefix = 'xyz/';
var s3 = new AWS.S3({params: {Bucket: bucketName}, region: 'us-west-2'});

var done = function(err, data) {
  if (err) console.log(err);
  else console.log(data);
};

s3.listObjects({Prefix: oldPrefix}, function(err, data) {
  if (data.Contents.length) {
    async.each(data.Contents, function(file, cb) {
      var params = {
        Bucket: bucketName,
        CopySource: bucketName + '/' + file.Key,
        Key: file.Key.replace(oldPrefix, newPrefix)
      };
      s3.copyObject(params, function(copyErr, copyData){
        if (copyErr) {
          console.log(err);
        }
        else {
          console.log('Copied: ', params.Key);
          cb();
        }
      });
    }, done);
  }
});

希望这可以帮助!

Answer 2

这是一个以"异步等待"方式执行此操作的代码段:

const AWS = require('aws-sdk');
AWS.config.update({
  credentials: new AWS.Credentials(....), // credential parameters
});
AWS.config.setPromisesDependency(require('bluebird'));
const s3 = new AWS.S3();

... ...

const bucketName = 'bucketName';        // example bucket
const folderToMove = 'folderToMove/';   // old folder name
const destinationFolder = 'destinationFolder/'; // new destination folder 
try {
    const listObjectsResponse = await s3.listObjects({
        Bucket: bucketName,
        Prefix: folderToMove,
        Delimiter: '/',
    }).promise();

    const folderContentInfo = listObjectsResponse.Contents;
    const folderPrefix = listObjectsResponse.Prefix;

    await Promise.all(
      folderContentInfo.map(async (fileInfo) => {
        await s3.copyObject({
          Bucket: bucketName,
          CopySource: `${bucketName}/${fileInfo.Key}`,  // old file Key
          Key: `${destinationFolder}/${fileInfo.Key.replace(folderPrefix, '')}`, // new file Key
        }).promise();
    
        await s3.deleteObject({
          Bucket: bucketName,
          Key: fileInfo.Key,
        }).promise();
      })
    );
} catch (err) {
  console.error(err); // error handling
}

Answer 3

上述命令都不能处理大型目录，因为该list-objects-v2命令一次返回不超过 1000 个结果，从而提供了访问其他“页面”的连续令牌。

这是使用现代 v3 sdk 的解决方案：

const copyAll = async ({
  s3Client,
  sourceBucket,
  targetBucket = sourceBucket,
  sourcePrefix,
  targetPrefix,
  concurrency = 1,
  deleteSource = false,
}) => {
  let ContinuationToken;

  const copyFile = async (sourceKey) => {
    const targetKey = sourceKey.replace(sourcePrefix, targetPrefix);

    await s3Client.send(
      new CopyObjectCommand({
        Bucket: targetBucket,
        Key: targetKey,
        CopySource: `${sourceBucket}/${sourceKey}`,
      }),
    );

    if (deleteSource) {
      await s3Client.send(
        new DeleteObjectCommand({
          Bucket: sourceBucket,
          Key: sourceKey,
        }),
      );
    }
  };

  do {
    const { Contents = [], NextContinuationToken } = await s3Client.send(
      new ListObjectsV2Command({
        Bucket: sourceBucket,
        Prefix: sourcePrefix,
        ContinuationToken,
      }),
    );

    const sourceKeys = Contents.map(({ Key }) => Key);

    await Promise.all(
      new Array(concurrency).fill(null).map(async () => {
        while (sourceKeys.length) {
          await copyFile(sourceKeys.pop());
        }
      }),
    );

    ContinuationToken = NextContinuationToken;
  } while (ContinuationToken);
};

如果这部Promise.all分不清楚，那它只是一个穷人的“线程池”，允许您同时复制多个文件，这可以显着加快速度。这些不使用任何带宽，因为内容是在 AWS 中复制的，因此我对 20 或更高的值没有任何问题concurrency。为了清楚起见，它只是以下的并行版本：

const sourceKeys = Contents.map(({ Key }) => Key);

while (sourceKeys.length) {
  await copyFile(sourceKeys.pop());
}

Answer 4

对 Aditya Manohar 代码的一个小改动，改进了 s3.copyObject 函数中的错误处理，并在执行复制请求后通过删除源文件来实际完成“移动”请求：

const AWS = require('aws-sdk');
const async = require('async');
const bucketName = 'foo';
const oldPrefix = 'abc/';
const newPrefix = 'xyz/';

const s3 = new AWS.S3({
    params: {
        Bucket: bucketName
    },
    region: 'us-west-2'
});


// 1) List all the objects in the source "directory"
s3.listObjects({
    Prefix: oldPrefix
}, function (err, data) {



    if (data.Contents.length) {

        // Build up the paramters for the delete statement
        let paramsS3Delete = {
            Bucket: bucketName,
            Delete: {
                Objects: []
            }
        };

        // Expand the array with all the keys that we have found in the ListObjects function call, so that we can remove all the keys at once after we have copied all the keys
        data.Contents.forEach(function (content) {
            paramsS3Delete.Delete.Objects.push({
                Key: content.Key
            });
        });

        // 2) Copy all the source files to the destination
        async.each(data.Contents, function (file, cb) {
            var params = {
                CopySource: bucketName + '/' + file.Key,
                Key: file.Key.replace(oldPrefix, newPrefix)
            };
            s3.copyObject(params, function (copyErr, copyData) {

                if (copyErr) {
                    console.log(err);
                } else {
                    console.log('Copied: ', params.Key);
                }
                cb();
            });
        }, function (asyncError, asyncData) {
            // All the requests for the file copy have finished
            if (asyncError) {
                return console.log(asyncError);
            } else {
                console.log(asyncData);

                // 3) Now remove the source files - that way we effectively moved all the content
                s3.deleteObjects(paramsS3Delete, (deleteError, deleteData) => {
                    if (deleteError) return console.log(deleteError);

                    return console.log(deleteData);
                })

            }
        });
    }
});

请注意，我已将cb()回调函数移到if-then-else 循环之外。这样即使发生错误，异步模块也会触发该done()功能。

Answer 5

对递归复制文件夹的原始代码进行更多更新。一些限制是代码不能处理每个 Prefix 超过 1000 个对象，当然如果您的文件夹很深，深度限制。

import AWS from 'aws-sdk';

AWS.config.update({ region: 'ap-southeast-1' });

/**
 * Copy s3 folder
 * @param {string} bucket Params for the first argument
 * @param {string} source for the 2nd argument
 * @param {string} dest for the 2nd argument
 * @returns {promise} the get object promise
 */
export default async function s3CopyFolder(bucket, source, dest) {
  // sanity check: source and dest must end with '/'
  if (!source.endsWith('/') || !dest.endsWith('/')) {
    return Promise.reject(new Error('source or dest must ends with fwd slash'));
  }

  const s3 = new AWS.S3();

  // plan, list through the source, if got continuation token, recursive
  const listResponse = await s3.listObjectsV2({
    Bucket: bucket,
    Prefix: source,
    Delimiter: '/',
  }).promise();

  // copy objects
  await Promise.all(
    listResponse.Contents.map(async (file) => {
      await s3.copyObject({
        Bucket: bucket,
        CopySource: `${bucket}/${file.Key}`,
        Key: `${dest}${file.Key.replace(listResponse.Prefix, '')}`,
      }).promise();
    }),
  );

  // recursive copy sub-folders
  await Promise.all(
    listResponse.CommonPrefixes.map(async (folder) => {
      await s3CopyFolder(
        bucket,
        `${folder.Prefix}`,
        `${dest}${folder.Prefix.replace(listResponse.Prefix, '')}`,
      );
    }),
  );

  return Promise.resolve('ok');
}