【发布时间】:2019-11-04 15:46:29
【问题描述】:
我要做什么
从浏览器客户端上传 PDF 文件,而不会暴露任何凭据或任何令人讨厌的东西。基于this,我认为可以做到,但它似乎对我不起作用。
前提是:
您根据提供给作为 JavaScript AWS 开发工具包一部分的函数的一组参数从 S3 存储桶请求预签名 URL
您将此 URL 提供给前端,前端可以使用它在 S3 存储桶中放置文件,而无需在前端使用任何凭据或身份验证。
从 S3 获取预签名 URL
这部分很简单,对我有用。我只是用这个小 JS 块从 S3 请求一个 URL:
const s3Params = {
Bucket: uploadBucket,
Key: `${fileId}.pdf`,
ContentType: 'application/pdf',
Expires: 60,
ACL: 'public-read',
}
let uploadUrl = s3.getSignedUrl('putObject', s3Params);
使用预签名 URL 将文件上传到 S3
这是不起作用的部分,我不知道为什么。 这小块代码基本上使用 PUT 请求将数据块发送到 S3 存储桶预签名 URL。
const result = await fetch(response.data.uploadURL, {
method: 'put',
body: blobData,
});
PUT 还是 POST?
我发现使用任何 POST 请求都会导致 400 Bad Request,所以 PUT 就是这样。
我看过的
Content-Type(在我的例子中,它是 application/pdf,所以 blobData.type)——它们在后端和前端之间匹配。
Similar use case。看看这个,似乎不需要在 PUT 请求中提供任何标头,并且签名的 URL 本身就是文件上传所必需的。
Something weird 我不明白。看起来我可能需要将文件的长度和类型传递给对 S3 的 getSignedUrl 调用。
向公众公开我的存储桶(禁止使用)
前端(fileUploader.js,使用 Vue):
...
uploadFile: async function(e) {
/* receives file from simple input element -> this.file */
// get signed URL
const response = await axios({
method: 'get',
url: API_GATEWAY_URL
});
console.log('upload file response:', response);
let binary = atob(this.file.split(',')[1]);
let array = [];
for (let i = 0; i < binary.length; i++) {
array.push(binary.charCodeAt(i));
}
let blobData = new Blob([new Uint8Array(array)], {type: 'application/pdf'});
console.log('uploading to:', response.data.uploadURL);
console.log('blob type sanity check:', blobData.type);
const result = await fetch(response.data.uploadURL, {
method: 'put',
headers: {
'Access-Control-Allow-Methods': '*',
'Access-Control-Allow-Origin': '*',
'x-amz-acl': 'public-read',
'Content-Type': blobData.type
},
body: blobData,
});
console.log('PUT result:', result);
this.uploadUrl = response.data.uploadURL.split('?')[0];
}
后端(fileReceiver.js):
'use strict';
const uuidv4 = require('uuid/v4');
const aws = require('aws-sdk');
const s3 = new aws.S3();
const uploadBucket = 'the-chumiest-bucket';
const fileKeyPrefix = 'path/to/where/the/file/should/live/';
const getUploadUrl = async () => {
const fileId = uuidv4();
const s3Params = {
Bucket: uploadBucket,
Key: `${fileId}.pdf`,
ContentType: 'application/pdf',
Expires: 60,
ACL: 'public-read',
}
return new Promise((resolve, reject) => {
let uploadUrl = s3.getSignedUrl('putObject', s3Params);
resolve({
'statusCode': 200,
'isBase64Encoded': false,
'headers': {
'Access-Control-Allow-Origin': '*',
'Access-Control-Allow-Headers': '*',
'Access-Control-Allow-Credentials': true,
},
'body': JSON.stringify({
'uploadURL': uploadUrl,
'filename': `${fileId}.pdf`
})
});
});
};
exports.handler = async (event, context) => {
console.log('event:', event);
const result = await getUploadUrl();
console.log('result:', result);
return result;
}
无服务器配置(serverless.yml):
service: ocr-space-service
provider:
name: aws
region: ca-central-1
stage: ${opt:stage, 'dev'}
timeout: 20
plugins:
- serverless-plugin-existing-s3
- serverless-step-functions
- serverless-pseudo-parameters
- serverless-plugin-include-dependencies
layers:
spaceOcrLayer:
package:
artifact: spaceOcrLayer.zip
allowedAccounts:
- "*"
functions:
fileReceiver:
handler: src/node/fileReceiver.handler
events:
- http:
path: /doc-parser/get-url
method: get
cors: true
startStateMachine:
handler: src/start_state_machine.lambda_handler
role:
runtime: python3.7
layers:
- {Ref: SpaceOcrLayerLambdaLayer}
events:
- existingS3:
bucket: ingenio-documents
events:
- s3:ObjectCreated:*
rules:
- prefix:
- suffix: .pdf
startOcrSpaceProcess:
handler: src/start_ocr_space.lambda_handler
role:
runtime: python3.7
layers:
- {Ref: SpaceOcrLayerLambdaLayer}
parseOcrSpaceOutput:
handler: src/parse_ocr_space_output.lambda_handler
role:
runtime: python3.7
layers:
- {Ref: SpaceOcrLayerLambdaLayer}
renamePdf:
handler: src/rename_pdf.lambda_handler
role:
runtime: python3.7
layers:
- {Ref: SpaceOcrLayerLambdaLayer}
parseCorpSearchOutput:
handler: src/node/pdfParser.handler
role:
runtime: nodejs10.x
saveFileToProcessed:
handler: src/node/saveFileToProcessed.handler
role:
runtime: nodejs10.x
stepFunctions:
stateMachines:
ocrSpaceStepFunc:
name: ocrSpaceStepFunc
definition:
StartAt: StartOcrSpaceProcess
States:
StartOcrSpaceProcess:
Type: Task
Resource: "arn:aws:lambda:#{AWS::Region}:#{AWS::AccountId}:function:#{AWS::StackName}-startOcrSpaceProcess"
Next: IsDocCorpSearchChoice
Catch:
- ErrorEquals: ["HandledError"]
Next: HandledErrorFallback
IsDocCorpSearchChoice:
Type: Choice
Choices:
- Variable: $.docIsCorpSearch
NumericEquals: 1
Next: ParseCorpSearchOutput
- Variable: $.docIsCorpSearch
NumericEquals: 0
Next: ParseOcrSpaceOutput
ParseCorpSearchOutput:
Type: Task
Resource: "arn:aws:lambda:#{AWS::Region}:#{AWS::AccountId}:function:#{AWS::StackName}-parseCorpSearchOutput"
Next: SaveFileToProcessed
Catch:
- ErrorEquals: ["SqsMessageError"]
Next: CorpSearchSqsErrorFallback
- ErrorEquals: ["DownloadFileError"]
Next: CorpSearchDownloadFileErrorFallback
- ErrorEquals: ["HandledError"]
Next: HandledNodeErrorFallback
SaveFileToProcessed:
Type: Task
Resource: "arn:aws:lambda:#{AWS::Region}:#{AWS::AccountId}:function:#{AWS::StackName}-saveFileToProcessed"
End: true
ParseOcrSpaceOutput:
Type: Task
Resource: "arn:aws:lambda:#{AWS::Region}:#{AWS::AccountId}:function:#{AWS::StackName}-parseOcrSpaceOutput"
Next: RenamePdf
Catch:
- ErrorEquals: ["HandledError"]
Next: HandledErrorFallback
RenamePdf:
Type: Task
Resource: "arn:aws:lambda:#{AWS::Region}:#{AWS::AccountId}:function:#{AWS::StackName}-renamePdf"
End: true
Catch:
- ErrorEquals: ["HandledError"]
Next: HandledErrorFallback
- ErrorEquals: ["AccessDeniedException"]
Next: AccessDeniedFallback
AccessDeniedFallback:
Type: Fail
Cause: "Access was denied for copying an S3 object"
HandledErrorFallback:
Type: Fail
Cause: "HandledError occurred"
CorpSearchSqsErrorFallback:
Type: Fail
Cause: "SQS Message send action resulted in error"
CorpSearchDownloadFileErrorFallback:
Type: Fail
Cause: "Downloading file from S3 resulted in error"
HandledNodeErrorFallback:
Type: Fail
Cause: "HandledError occurred"
错误:
403 禁止
PUT 响应
响应 {type: "cors", url: "https://{bucket-name}.s3.{region-id}.amazonaw...nedHeaders=host%3Bx-amz-acl&x-amz-acl=public-读”,重定向:假,状态:403,确定:假,...} 身体: (...) 身体使用:假 标头:标头{} 好的:假的 重定向:假 状态:403 statusText:“禁止” 类型:“cors” 网址:“https://{bucket-name}.s3.{region-id}.amazonaws.com/actionID.pdf?Content-Type=application%2Fpdf&X-Amz-Algorithm=SHA256&X-Amz-Credential=CREDZ-&X -Amz-Date=20190621T192558Z&X-Amz-Expires=900&X-Amz-Security-Token={token}&X-Amz-SignedHeaders=host%3Bx-amz-acl&x-amz-acl=public-read" 原型:响应
我在想什么
我认为使用 AWS S3 开发工具包提供给 getSignedUrl 调用的参数不正确,尽管它们遵循 AWS 文档建议的结构(解释为 here)。除此之外,我真的不知道为什么我的请求被拒绝了。我什至尝试过将我的 Bucket 完全公开给公众,但仍然没有成功。
编辑
#1:
阅读this 后,我尝试将我的 PUT 请求结构如下:
let authFromGet = response.config.headers.Authorization;
const putHeaders = {
'Authorization': authFromGet,
'Content-Type': blobData,
'Expect': '100-continue',
};
...
const result = await fetch(response.data.uploadURL, {
method: 'put',
headers: putHeaders,
body: blobData,
});
这导致 400 Bad Request 而不是 403;不同,但仍然是错误的。显然,在请求中放置任何标头都是错误的。
【问题讨论】:
-
你能把你的日志贴出来
-
你能把
method: 'post'设置成put吗?并尝试? -
@AritraChakraborty
put输出相同 -
@ChumiestBucket 我很好奇你是否有解决方案?你把问题写得如此出色,即使你自己写了,如果没有解决方案也太可惜了。
标签: node.js amazon-web-services amazon-s3 serverless-framework