Hi there, I have some questions regarding Haproxy Configuration in Version HA-Proxy version 2.0.23, which is not clear by reading the official documentation. I hope you would have some ideas how this could be solved.
What I wish to accomplish: A frontend application is called by an url with a context path in it. Haproxy should set a Header in the backend section with `http-request set-header Host` whereas the set Host contains the context_path found in the url-path. I try to make it clear with an example: The called url looks like: `https://example.com/context_path/abc/etc` Out of this url I would need to set the following Host Header: `context_path.ms.example.com`, while the path remains `/context_path/abc/etc` While I find many fetch-examples for ACLs, I had to learn that most of them don’t work on `http-request set-header or set-env`. I tried to use `path_beg` or `path_reg`, which parses with errors, that the fetch method is unknown. So something like this doesn’t work: `http-request set-header Host %[path_reg(...)].ms.example.domain.com<http://ms.example.domain.com> if host_example` or this: `http-request set-var(req.url_context) path_beg,lower if host_example` Question: I am certain that this should somehow be possible, as I found even solutions to set variables or Headers by urlp, cookies, etc. What would be the explanation, why fetch methods like path_beg are not available in this context? And how to work around it? Thank you in advance and best regards, Maya Scheu
