Writing and Rewriting a URI

What the customer would like to do now is rewrite "/blah/blah/blah" to either "/a/b/c" or "/"

you can change (rewrite) uri sending to server (pool member) by using HTTP::uri command.

HTTP::uri

when the traffic returns, rewrite the uri to what it was originally.

response does not have uri. uri is in request.

when the traffic returns, rewrite the uri to what it was originally.

sorry what i said (above) may not be fully correct. if you mean uri which is embedded in response body, you may try to rewrite it using stream profile.

sol8115: Overview of the Stream profile

https://support.f5.com/kb/en-us/solutions/public/8000/100/sol8115.html

So I can rewrite the uri, but my impression from the customer is that he doesn't want the rewritten URI to be seen by the client's browser. He wants the end server(s) to see it, but not the not the client.

As for the Stream profile, this would be something I need to enable on the VIP itself, before I use it in the irule, correct? Since this VIP already has a HTTP profile, it seems like Stream would only work on the HTTP payload, but not the headers.

As for the Stream profile, this would be something I need to enable on the VIP itself, before I use it in the irule, correct?

yes

Since this VIP already has a HTTP profile, it seems like Stream would only work on the HTTP payload, but not the headers.

yes. if uri is not embedded in response body, you do not need stream profile. you can rewrite response header by using HTTP::header command which you already used in your irule.

So the one thing that still concerns me. Not sure if I'm misunderstanding the problem, but it seem to me this would be the flow.

Client -> "/a/b/c" -> Vip(redirects to pool redirect-pool) -> Servers.

That's fine but if i rewrite the irule so that /blah/blah/blah is rewritten as /a/b/c, when the traffic returns from the servers, I want to rewrite the uri back to what it was originally. I can do this based on what? Unfortunately, all I know how how to do this is based on uri as well. So...

Client -> "/blah/blah/blah/" -> VIP(uri is rewritten as "/a/b/c" and sent to redirect-pool) -> Servers -> VIP(rewritten to "/blah/blah/blah/") -> Client

Client -> "/a/b/c" -> Vip(redirects to pool redirect-pool) -> Servers - > VIP(also rewritten as "/blah/blah/blah/") -> Client

In the first case its "/blah/blah/blah/" is rewritten back to "/blah/blah/blah/" on its return trip. On the second case "/a/b/c" is also rewritten as "/blah/blah/blah/" on its return trip, something thats not desirable.

If instead "/blah/blah/blah/" is rewritten to "/", on the return trip, all redirected traffic is still rewritten as "/blah/blah/blah", which wouldn't be good either.

Am I misunderstanding the situation here?

The client browser needs to see "/blah/blah/blah" as the uri for the entire length of the session, but when the VIP redirects the request, the pool servers need to see "/a/b/c" as the uri instead.

After brainstorming with some coworkers, we came up with this.

when HTTP_REQUEST {
set uri_redirect 0
switch -glob [HTTP::path] {
"/blah/blah/blah*" {
set uri_redirect 1
HTTP::header replace "Host" "external.domain.com"
HTTP::redirect "https:// [getfield [HTTP::host] ":" 1][string map {/blah/blah/blah /a/b/c } [HTTP::path]]"
pool redirect-pool
snat automap
} "/a/b/c*" {
set uri_redirect 0
HTTP::header replace "Host" "external.domain.com"
pool redirect-pool
snat automap
} default { pool default-pool }
}
}
when HTTP_RESPONSE {
if { [HTTP::is_redirect] } {
if { $uri_redirect == 1 } { HTTP::header replace "Host" "internal.domain.com"
HTTP::redirect "https:// [getfield [HTTP::host] ":" 1 ][string map { /a/b/c /blah/blah/blah } [HTTP::path]]"
} else {
HTTP::header replace "Host" "internal.domain.com"
}
}
}

However, after trying it out in the editor and fixing a bunch of errors, I still get

line 21: [command is not valid in current event context (HTTP_RESPONSE)] [HTTP::host]
line 21: [command is not valid in current event context (HTTP_RESPONSE)] [HTTP::path]

Anyone know of a way of rewriting the URI without resorting to using [HTTP::host] or [HTTP::path] ?