Appending Path to Host Haproxy
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...
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
Sarah Jenkins is a veteran tech journalist with over 12 years of experience covering artificial intelligence, mobile innovations, and digital ethics. Her insights have appeared in leading technology publications worldwide.
