Azure 函数未写入图像文件答案

【问题标题】：Azure function is not writing the image fileAzure 函数未写入图像文件
【发布时间】：2021-09-24 10:14:39
【问题描述】：

我是 azure 函数应用的新手。我正在开发一个应用程序来生成 wordcloud，为此，我正在从 Cosmos DB 中获取我的数据。使用 VS Code 在本地一切正常。当我在 azure 函数应用程序上部署 azure 函数时，部署成功，在浏览器中，我收到以下消息。

This HTTP-triggered function was executed successfully. Pass a name in the query string or the request body for a personalized response.

表示部署成功。但是当我传递 Query 参数并调用 get_wordcloud 函数时，它会抛出 500 Internal Server Error。我的猜测是它无法在 Azure 环境中写入图像文件。以下是我的__init__.py 文件：

import logging

import azure.functions as func

from azure.cosmos import CosmosClient
import os

from pandas import json_normalize

from wordcloud import WordCloud, STOPWORDS

from PIL import Image


def main(req: func.HttpRequest) -> func.HttpResponse:
    logging.info('Python HTTP trigger function processed a request.')

    db_name = req.params.get('db_name')
    container_name = req.params.get('container_name')
    if not db_name and not container_name:
        try:
            req_body = req.get_json()
        except ValueError:
            pass
        else:
            db_name = req_body.get('db_name')
            container_name = req_body.get('container_name')

    if db_name and container_name:
        url = os.environ.get('ACCOUNT_URI')
        
        key = os.environ.get('ACCOUNT_KEY')

        client = CosmosClient(url, credential=key)

        database = client.get_database_client(db_name)
        container = database.get_container_client(container_name)
        print(database)
        print(container)

        query = 'SELECT * FROM c'
        result = list(container.query_items(
            query, enable_cross_partition_query=True))

        df = json_normalize(result)
        stopwords = set(STOPWORDS)
        wordcloud = WordCloud(
            background_color='white',
            stopwords=stopwords,
            max_words=500,
            width=1080,
            height=640,
        ).generate(str(df))
        wordcloud.to_file("wordcloud_result.png")
        file = open(u'wordcloud_result.png', 'rb')
        result = file.read()
        return func.HttpResponse(result)
    else:
        return func.HttpResponse(
            "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response.",
            status_code=200
        )

下面是function.json文件：

{
  "scriptFile": "__init__.py",
  "bindings": [
    {
      "authLevel": "function",
      "type": "httpTrigger",
      "direction": "in",
      "name": "req",
      "methods": [
        "get",
        "post"
      ]
    },
    {
      "type": "http",
      "direction": "out",
      "name": "$return"
    }
  ]
}

在__init__.py 替换下面的代码时

wordcloud.to_file("wordcloud_result.png")
file = open(u'wordcloud_result.png', 'rb')
result = file.read()
return func.HttpResponse(result)

使用以下代码

return func.HttpResponse('Successful')

它正在成功运行。

【问题讨论】：

500 状态码表示存在未处理的异常。我建议将整个函数代码放在 try/catch 块中并记录异常。请在您的问题中分享该例外情况。

标签： azure-functions azure-cosmosdb azure-http-trigger

【解决方案1】：

不是 python 用户，但我注意到您没有标头内容类型 (application/octet-stream)，您应该返回 StreamContent... 看看这个版本的问题C#How do I return a blob from a HTTP triggered Azure Function?

【讨论】：