Google App Engine返回“错误：服务器错误”

Question

My app works locally and runs smoothly at localhost:8080. It seems there's an issue when the app is executed in the Google servers.

I am pretty sure that I have some packages missing, I already added the cloudstorage and requests packages into my lib folder.

I would just like to know which ones do I have to download and add to the lib folder, here's what I am using in my Python app:

import os, sys, requests, csv, urllib2, webapp2                                 
import xml.etree.ElementTree as ET                                              
from datetime import date, timedelta, datetime                                  
from google.appengine.api import app_identity                                   
import cloudstorage as gcs

EDIT:

I think I'm wrong and the packages part has nothing to do with the Error.

I found in the Stack Trace Sample these few lines:

Body: "<?xml version='1.0' encoding='UTF-8'?>
<Error>
<Code>AccessDenied</Code>
<Message>Access denied.</Message>
<Details>
Caller does not have storage.objects.create access to bucket bucket.
</Details>
</Error>". Extra info: None.

I am actually writing in a csv file on Google Cloud Storage, here's my few lines of code that are probably important

        currentFileName = "/bucket/" + self.domain + "_" + self.startDate +"_" \
+ self.endDate +'.csv'

with gcs.open(currentFileName, 'w') as csvfile:                         
            fieldnames = ['ID', 'URL', 'Comments', 'Em...

...
writer = csv.DictWriter(csvfile,fieldnames = fieldnames)            

Did I do a mistake at the file path in the Bucket? I'm a little confused on how to check if it's creating the file correctly also.

EDIT 2:

Do I need to use this line of code somewhere?

    bucket_name = os.environ.get('BUCKET_NAME', app_identity.get_default_gc\
s_bucket_name())  

Answer 1

The error was the bucket directory, getting the bucket name with

bucket_name = os.environ.get('BUCKET_NAME', app_identity.get_default_gc\
s_bucket_name())  

Then modifying the currentFileName to the correct directory which is

currentFileName = "/" + bucket_name + "/" + self.domain + "_" + self.startDate +"_" \
+ self.endDate +'.csv'

Fixed the 500 Error: Server Error