I am new to haproxy (actually proxy'ing in general) and I can't figure out how to add a path to my backend. I have my backend defined as:
server server1 ns.foo.com:7170 check
I want to add /web such that the request is directed to .
Thanks, Mark
2 Answers
What you need is HTTP rewriting
Adding this to your backend should solve your problem:
acl p_root path -i / http-request set-path /web if p_root If you would like to send a request coming in a given port to a specific path, you can modify the request either in the frontend or backend configuration by specifying a http-request rule using the set-path action
For example if you would like to send any request to a /web then you should write
http-request set-path /web into your backend configuration
Otherwise if you would like to prepend the incoming request path with /web (so for example
localhost:[port]/somepath
should go to
serverhost:[serverport]/web/somepath) as Mawardy asked.
Then you should also use the %[path] variable like this
http-request set-path /web/%[path] I have created a proof of concept of a spring server running with 2 instances in docker which are loadbalanced with a HA proxy in docker that also modifies the path depending on which server won the loadbalancing. For this the ha proxy is configured to loadbalance between its own frontends which has their own backend with their modified path
The configuration looks like this
defaults retries 3 maxconn 20 timeout connect 5s timeout client 6s timeout server 6s frontend http-in bind *:9002 mode http use_backend proxy-backend backend proxy-backend balance roundrobin mode http option forwardfor http-response set-header X-Forwarded-Port %[dst_port] http-response set-header X-ProxyServer %s server proxy-server-1 localhost:9000 server proxy-server-2 localhost:9001 frontend proxy-in1 bind *:9000 mode http use_backend poc-server2 frontend http-in2 bind *:9001 mode http use_backend poc-server1 backend poc-server1 mode http http-response set-header X-Server %s http-request set-path /api/one/%[path] server poc-server-1 proxypochost1:9000 backend poc-server2 mode http http-response set-header X-Server %s http-request set-path /api/two/%[path] server poc-server-2 proxypochost2:9001 For more information you can check the whole project with some additional information in its readme here: ha-proxy-poc
