Using basicauth - 401 status after 200 status

Traefik Traefik v2
1

Hi,

I'm using traefik to receive HTTPS requests with basic authentication. In the access logs I see a request come on with a 200 response, but often this is followed by 1 or more 401 responses. For example:

user [16/Sep/2022:09:36:41 +0000] "POST /api/message/test HTTP/1.1" 200 12 "-" "-" 700329 "nifi-router@file" "http://nifi:3001" 31ms
- [16/Sep/2022:09:36:41 +0000] "POST /api/message/test HTTP/1.1" 401 17 "-" "-" 700331 "nifi-router@file" "-" 0ms
- [16/Sep/2022:09:36:41 +0000] "POST /api/message/test HTTP/1.1" 401 17 "-" "-" 700332 "nifi-router@file" "-" 0ms
- [16/Sep/2022:09:36:41 +0000] "POST /api/message/test HTTP/1.1" 401 17 "-" "-" 700335 "nifi-router@file" "-" 0ms

My config looks like this:

[http.middlewares.admin.basicAuth]
        users = ["user:password", "user2:pass", ....]
  
  [http.routers.nifi-router]
    entrypoints = ["queue"]
    rule = "Host(`queue.com`) && PathPrefix(`/api/message/test`)"
    service = "nifi-3001"
    middlewares = ["admin"]
    [http.routers.nifi-router.tls]


[http.services]
  [http.services.nifi-3001]
    [[http.services.nifi-3001.loadBalancer.servers]]
      url = "http://nifi:3001"

I don't understand why these 401 responses show up after there has been a 200 response already?

2

Are you sure this is coming from Traefik? Is Traefik routing requests to multiple services and there are instances that do not support the route? Is your app itself returning a 401 for whatever reason?

3

All requests show the same nifi-router in the logs though. And the router has only 1 service in it.

I think this is a client problem after looking into it more. If I test this same endpoint myself using curl, I only get 200 responses and the 401 responses are gone.
I also tried replacing Traefik with Apache HTTPD as a test, but it shows the same behaviour with this client. First 200 response, followed by 401 response.