I have some stateful chat servers (SockJS) running in docker swarm mode. When doing dig chat I get an unordered randomized list of servers for example:
(every time the order is different) 10.0.0.12 10.0.0.10 10.0.0.11 The chat is accessed by a chatName url parameter. Now I want to be able to run a chat-load-balancer service in docker with multiple replicas using the haproxy image. The problem is that docker always resolves to a randomized list when doing dig chat. I want to map the chatName param from the url to a fixed server which always have the same ip from the list of ips of dig chat. So the mapping of the url_param should not be based on the position of the server in the list, but solely on the ip of the server. So for example ?chatName=fun should always route to ip 10.0.0.12, no matter what. My current haproxy.cfg is: defaults mode http timeout client 5s timeout connect 5s timeout server 5s frontend frontend_chat bind :80 mode http timeout client 120s option forwardfor option http-server-close option http-pretend-keepalive default_backend backend_chat backend backend_chat balance url_param chatName timeout server 120s server chat chat:80 At the moment it seems that only the Commercial Subscribtion of Nginx can handle this kind of cases using the sticky route $variable ...; directive in the upstream module.
