runtime servers: admin_state always return maint

[devops-email]

I'm using a HAProxy 2.4.27 with Data Plane API 2.6.5 on Linux and when I try to get the admin_state for the runtime servers, it always returns maint admin_state, doesn't matter if server is on READY, DRAIN or MAINT state:

$ curl -sX GET --user admin:verysecretpass "http://10.1.1.1:5555/v2/services/haproxy/runtime/servers/webserver1?backend=backend1" | jq
{
  "address": "10.1.1.1",
  "admin_state": "maint",
  "id": "1",
  "name": "webserver1",
  "operational_state": "up",
  "port": 8080
}

Checking the Data Plane API code (GetServerState() and GetServersState() in handlers/runtime_server.go) and its dependencies, I found GetServerAdminState() in https://github.com/haproxytech/client-native/blob/master/misc/bits.go and I solved the problem by making the changes below:

From:

if mask.Any(B0, B1, B5) {
  return "maint", nil
}
if mask.Any(B3, B4) {
  return "drain", nil
}

To:

if mask.Any(B0) {
  return "maint", nil
}
if mask.Any(B1) {
  return "drain", nil
}

I don't know if it's a feature that isn't normally used, as I haven't found anyone else reporting this problem. I don't have any information on whether this problem continues in the most recent versions of HAProxy and Data Plane API, but it was the solution adopted to resolve the problem in these versions.