Weird 502 bad gateway when using Httpresponse: content_type='text/csv' App service

Question

Greetings everyone,

without knowingly changing anything, I suddenly get a "502 Bad Gateway" error when requesting a ~12-18KB *.csv file from my django backend running in Docker using the App Service.

• All other calls to this backend, such as requesting JSON data, function properly in Azure.
• The Log stream reveals that my Django Backend responds with a "HTTP/1.1" 200" success on the GET for the *.csv (just like with the other GETs )
• The same GET for the *.csv works flawlessly when running the same DOCKER-compose container in my windows docker environment
• The GET for the *.csv used to work before
• The only difference to the functioning GETs is the content type, data & headers of the response :

response = HttpResponse(
content_type='text/csv',
headers={'Content-Disposition': 'attachment; filename="DownloadData.csv"'},
)

• Given that all other GETs function properly & no other issues seem to be affecting the whole app I am out of ideas and posts to look for solutions. It doesn't seem to be CORS or access related. --> Does anyone have an idea why the 502 crops up?

Thank you for your time.
Pascal

Answer 1

To whoever has a similar problem: after a lot more searching & testing I believe that I have found the answer:
-> The filename of the of the csv contained the symbol "ö".

My guess is that this somehow did not pass through and somewhere cause an error on the way while I could not find those errors in the logs.
Anyway, it works now.