問題描述

我無法讓 python lambda 返回二進(jìn)制數(shù)據(jù).

引用:

API Gateway 將查看 Content-Type 和 Accept HTTP 標(biāo)頭來決定如何處理正文.

這意味著 Content-Type 響應(yīng)標(biāo)頭必須匹配 Accept 請求標(biāo)頭

解決方案:

1. 將 API 網(wǎng)關(guān)中的二進(jìn)制媒體類型設(shè)置為您的 mime 類型:image/jpg

2. 在你的 HTTP 請求集中 Accept: image/jpg

3. 在你的 HTTP 響應(yīng)集中 Content-Type: image/jpg

<塊引用>

<代碼>{isBase64Encoded":真，狀態(tài)碼":200，標(biāo)題":{內(nèi)容類型":圖像/jpg"}，正文":base64.b64encode(content_bytes).decode(utf-8")}

4. 接下來，我們必須告訴 CloudFront 接受請求中的Accept"標(biāo)頭.因此，在 CloudFront 分發(fā)中，單擊您的 API Gateway 實(shí)例(ID 可單擊)，一旦重定向到 CloudFront 實(shí)例，轉(zhuǎn)到 Behaviour 選項(xiàng)卡，選擇您的 API 的路徑模式(例如:/api/*) 并點(diǎn)擊編輯按鈕.

<塊引用>

在新屏幕上，您必須將 Accept 標(biāo)頭添加到白名單.

注意 1:如果您有多種文件類型，則必須將它們?nèi)刻砑拥?API 網(wǎng)關(guān)設(shè)置中的 Binary Media Types

注意 2:對于那些來自 serverless 并希望在部署 lambdas 時(shí)設(shè)置二進(jìn)制類型的用戶，請查看此帖子:為 API 網(wǎng)關(guān)設(shè)置二進(jìn)制媒體類型

插件:- 無服務(wù)器-apigw-二進(jìn)制風(fēng)俗:apigw二進(jìn)制:類型:- '圖像/JPEG'

cloudfront 的 serverless.yml 文件應(yīng)包含:

資源:WebAppCloudFront 分布:類型:AWS::CloudFront::Distribution特性:分布配置:...緩存行為:...-#API 調(diào)用...轉(zhuǎn)發(fā)值:...標(biāo)題:- 授權(quán)- 接受

I cannot get python lambda to return binary data. The node-template for thumbnail images works fine but I cannot get a python lambda to work. Below is the relevant lines from my lambda. The print("image_data " + image_64_encode) line prints a base64 encoded image to the logs.

def lambda_handler(event, context):
    img_base64 = event.get('base64Image')
    if img_base64 is None:
        return respond(True, "No base64Image key")

    img = base64.decodestring(img_base64)
    name = uuid.uuid4()
    path = '/tmp/{}.png'.format(name)

    print("path " + path)

    image_result = open(path, 'wb')
    image_result.write(img)
    image_result.close()

    process_image(path)

    image_processed_path = '/tmp/{}-processed.png'.format(name)
    print("image_processed_path " + image_processed_path)
    image_processed = open(image_processed_path, 'rb')
    image_processed_data = image_processed.read()
    image_processed.close()
    image_64_encode = base64.encodestring(image_processed_data)

    print("image_data " + image_64_encode)


    return respond(False, image_64_encode)


def respond(err, res):
    return {
        'statusCode': '400' if err else '200',
        'body': res,
        'headers': {
            'Content-Type': 'image/png',
        },
        'isBase64Encoded': 'true'
    }

Any pointers to what I'm doing wrong?

Following all the steps above didn't work on my case, because having the binary support for content-type = */* will convert all responses to binary.

My case:

• Multiple lambda functions returning json (text), just a single lambda returning a binary file. All have lambda proxy enabled.

• The lambdas are in an API Gateway

• The API Gateway is behind CloudFront

Hint: I have notice an important information in the API Gateway -> Settings

Quoting:

API Gateway will look at the Content-Type and Accept HTTP headers to decide how to handle the body.

This means that the Content-Type response header must match Accept request header

Solution:

1. Set Binary Media Types in API gateway to your mime type: image/jpg

2. In your HTTP request set Accept: image/jpg

3. In your HTTP response set Content-Type: image/jpg

{
  "isBase64Encoded": True,
  "statusCode": 200,
  "headers": { "content-type": "image/jpg"},
  "body":  base64.b64encode(content_bytes).decode("utf-8")
}

4. Next we must tell CloudFront to accept the 'Accept' header from the request. So, in CloudFront distribution, click on your API Gateway instance (ID is clickable) and once redirected to CloudFront instance go to Behaviour tab, select the path-pattern of your API (example: /api/*) and click on Edit button.

On the new screen, you have to add Accept header to Whitelist.

Note 1: If you have multiple file types, you must add them all to Binary Media Types in the API gateway settings

Note 2: For those coming from serverless and want to set the binary types when deploying your lambdas, then check this post: setting binary media types for API gateway

plugins:
  - serverless-apigw-binary

custom:
  apigwBinary:
    types:
- 'image/jpeg'

The serverless.yml file for cloudfront should contain:

resources:
    WebAppCloudFrontDistribution:
      Type: AWS::CloudFront::Distribution
      Properties:
        DistributionConfig:
          ...
          CacheBehaviors:
            ...
            - 
              #API calls
              ...
              ForwardedValues:
                ...
                Headers:
                  - Authorization
                  - Accept

這篇關(guān)于如何在 Python 中從 AWS 中的 lambda 函數(shù)返回二進(jìn)制數(shù)據(jù)?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！