demoapp

• This app is created to reproduce mis-balancing in HAproxytech's ingress controller. It only servs /serverId endpoint which returns a json with serverId key and a random string which is the unique identifier for that server. For example: {serverId: ABCDEF}
• Ingress object of demoapp is configured like following:

  ingress:
    enabled: true
    className: "haproxy"
    annotations:
      haproxy.org/timeout-tunnel: "3600s"
      haproxy.org/backend-config-snippet: |
        balance url_param RouteToken check_post
    hosts:
      - host: test.demoapp
        paths:
        - path: /serverId
          pathType: Prefix

• HAproxy is configured to balance based on url_param RouteToken

Steps to install demoapp

1. Install HAproxy Ingress Controller with Nodeport service type

2. Install demoapp using chart given in demoapp repository

   helm install --create-namespace --namespace demoapp demoapp path/to/chart/given/in/repo

test-ha.py

• It is simple script that creates a hashmap serverId<->routeToken map. Here routeToken also is random string which signifies to which pod the request should endup. The hope is whenever there is RouteToken parameter in url HAproxy should always send the request to appropriate pod.
• For example, If script creates serverid map like following:

  serverId<->routeToken
  ABC<->123
  PQR<->456
  XYZ<->789

  • Then request with url http://test.demoapp:30080/serverId?RouteToken=123 should always endup on demoapp pod with serverId=ABC. The problem it deosn't happen number when pods are very high for example 50 demoapp pods
• There is function in test-ha.py test_serverid_mismatch which tests the above explain behaviour
• To run the script

  python test-ha.py http://test.demoapp:<whatever-nodeport-you-have-configured>