Dynamically update host for http health check

[jquinn]

Hi,

I’m trying to use the http health check to check multiple backends, similar to this post:

Checking files for Health Check on multiple servers

Currently I’m using HAProxy to route traffic through four different servers that offer the same service but are located on different physical boxes. I’m wanting to setup a healthcheck that goes against each individual server with the goal of stopping traffic getting routed when it fails to find a file. Everything that I have read online only shows that you can the check against one server though, for example: option httpchk GET http://service.com/healthcheck server server1.service.com 192.16…

I have the following configuration:

backend portal_http
mode http
http-request set-header X-Forwarded-Host dev002836.esri.com
option httpchk GET /arcgis/sharing/rest/content/items/382401ab2a924ad4ad0e93e071f09ddd
server dev005272.esri.com:7080 dev005272.esri.com:7080 check
server dev005273.esri.com:7080 dev005273.esri.com:7080 check

The problem is that the application expects a certain URL syntax when reaching that URL, (for example http://dev005272.esri.com:7080/arcgis/sharing/rest/content/items/382401ab2a924ad4ad0e93e071f09ddd) and will return a 301 if it doesn’t get it. Using the URL in the configuration returns a 301. This works as long as the backend isn’t down. If the backend is up and the URL is not accessible the response is still a 301, (following the redirect will of course return the 4XX or 5XX response code). The following health check configurations do work to get the 200 back:

option httpchk GET /arcgis/sharing/rest/content/items/382401ab2a924ad4ad0e93e071f09ddd HTTP/1.1\r\nHost:\ dev005272.esri.com:7080

or

option httpchk GET https://dev005272.esri.com:7080/arcgis/sharing/rest/content/items/382401ab2a924ad4ad0e93e071f09ddd

but the problem is it’s not checking both endpoints. Is there a way to dynamically set the Host header depending on the backend receiving the request?

Thanks for any help.