Haproxy Beginner Problem!

haproxy

I currently am using haproxy to do reverse_proxy on my end.

Unfortunately, I cannot get it to work!.

This is my config:

backend twisted 
        mode http
        timeout connect 10s
        timeout server 30s
        balance roundrobin
        server apache1 127.0.0.1:11111 weight 1 maxconn 512

backend cometd
        mode http
        timeout connect 5s
        timeout server 5m
        balance roundrobin
        server cometd1 127.0.0.1:12345 weight 1 maxconn 10000

frontend http_proxy #arbitrary name for the frontend
        bind *:80 #all interfaces at port 80
        mode http
        option forwardfor
        option http-server-close
        option http-pretend-keepalive
        default_backend twisted #by default forward the requests to apache

        acl req_cometd_path path_beg /comet/
        use_backend cometd if req_cometd_path 

        acl req_cometd_host hdr_dom(host) -i comet.okiez.com
        use_backend cometd if req_cometd_host
  1. If I try to access
    localhost/comet/test1/test2, haproxy
    forwards to the cometd backend
    correctly. However, the request path
    remains to be /comet/test1/test2,
    where my comet engine (orbited)
    doesn't handle the /comet/ part. Is
    there anyway to tell haproxy to drop
    the first /comet/ in the requests
    that gets directed to the cometd
    backend?
  2. As you can see, I have acl req_cometd_host hdr_dom(host) -i comet.okiez.com too. This simply stopped working. I don't know if accessing http://comet.localhost/test1/test2 or comet.127.0.0.1/test1/test2 makes any sense at all. How can I write acl req_cometd_host hdr_dom(host) -i to for localhost addresses?

Best Answer

Put the

reqrep ^([^\ ]*)\ /comet/(.*) \1\ /\2

into your backend definition. That way, Haproxy can use that path for its routing decision in the frontend. Here, a request with /comet at the beginning will match the req_cometd_path acl and will thus be routed to the correct backend.

In the backend itself, you can now adjust the request to be suitable for the actual application server behind it. Thus the stated rule above is going to remove the /comet from the beginning of the path for all requests going through the comet backend.

Edited (added the following):

Regarding your second issue, hdr_dom only matches if the stated string (in your case comet.okiez.com) is found isolated or delimited by dots in the header. You probably want to use one of

# matches if 'comet' is somewhere in the host
acl req_cometd_host hdr_dom(host) -i comet
# matches if 'comet' is at the beginning the host
acl req_cometd_host hdr_beg(host) -i comet
# matches if the host is comet.okiez.com
acl req_cometd_host hdr(host) -i comet.okiez.com

For more details, have a look at the Haproxy configuration manual.

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