Haproxy change part of url

Question

I have an app that was renamed and I want Haproxy to redirect to the correct path while preserving the request parameters

This is what I have:

acl old_name path_dir -i /old_name
   http-request set-path /new_name/%[query] if old_name

I want it to change from

www.site.com/old_name/Default.aspx?Id=123

to

www.site.com/new_name/Default.aspx?Id=123 but this is not working.

that this happen at IISM or MIT is not relevant and makes your question harder to understand. And what do you mean by "to have version control" ? — Flint, Aug 30 '16 at 17:19
You're right, it's not really relevant to the question. By version control, I mean that you can actually see with a commit that you added a redirect for a url instead of being hidden in some config in IISM. — Hugo Marques, Aug 31 '16 at 09:45

score 12 · Accepted Answer · edited Oct 16 '18 at 19:42

12

With HAProxy 1.5 : use a temporary header to build a new path from the existing one in the request and then directly perform a redirect

# Clean the request and remove any existing header named X-Rewrite
http-request del-header X-REWRITE

# Copy the full request URL into X-Rewrite unchanged
http-request add-header X-REWRITE %[url] if { path_beg /old_path }

# Change the X-REWRITE header to contain out new path
http-request replace-header X-REWRITE ^/old_path(/.*)?$ /new_path\1 if { hdr_cnt(X-REWRITE) gt 0 }

# Perform the 301 redirect
http-request redirect code 301 location http://%[hdr(host)]%[hdr(X-REWRITE)] if { hdr_cnt(X-REWRITE) gt 0 }

In HAProxy 1.6, use the regsub filter

http-request redirect code 301 location http://%[hdr(host)]%[url,regsub(^/old_path,/new_path,)] if { path_beg /old_path }

source among other useful configuration snippets

More information is available in the HAProxy documentation for the regsub keyword.

edited Oct 16 '18 at 19:42

Per Lundberg

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answered Aug 31 '16 at 09:49

Flint

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@flint When copying things you find on the internet verbatim, you should at least add some attribution to [the source](https://gist.github.com/meineerde/11865802f8338b18f123) (which would be me in this case). – Holger Just Mar 03 '17 at 14:35
You caught me @Holger. But I usually do. Late thanks. – Flint Mar 07 '17 at 13:44
Lovely solution, thanks! – napolux Feb 13 '20 at 15:03

score 7 · Answer 2 · answered Aug 30 '16 at 17:15

7

You are confusing url redirection with url rewriting to the backend.

Should you even want to rewrite, then according to the haproxy 1.6 documentation :

"set-path" rewrites the request path with the result of the evaluation of format string . The query string, if any, is left intact.

So the correct configuration in that case would be :

acl old_name path_dir -i /old_name
http-request set-path /new_name if old_name

To redirect the user :

redirect location /new_name if old_name

answered Aug 30 '16 at 17:15

Flint

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Yeah I was a bit confused with those two. The thing is that I want redirect the user to /new_name/Default.aspx?Id=123 and keep the "Default.aspx?Id=123" part. Doing a redirect like you mentioned just redirects to /new_name instead of /new_name/Default.aspx?Id=123. – Hugo Marques Aug 31 '16 at 08:48

score 3 · Answer 3 · edited Jul 02 '21 at 05:09

3

For anyone trying to make changes from uri to REST API, do not use the http-request redirect location because the header data is lost. Use http-request set-uri.

http-request set-uri %[url,regsub(^/old,/new,)] if { path_beg /old }

edited Jul 02 '21 at 05:09

Ward - Trying Codidact

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answered Jan 08 '19 at 18:48

Daniel Sá

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Haproxy change part of url

3 Answers3