Rewriting only part of the URI

Question

I have a request to rewrite only a certain part of our URI, while still passing the last part of the URI. I need to be able to catch all requests and rewrite just part of the URI.

I have a script already in use that does something similar, but saves the leading digits based on a specific length of the filename. In this case, all articles have a different number of characters, therefore I cannot use that rule.

I'd be thankful if anyone could point me in the right direction. Here's an example:

FROM:

http://ourdomain.com/newsletters/Directory2/*

TO:

http://ourdomain.com/newsletters/Directory3/*

The asterisk implies that we need to take the name of the article and pass it along as well, while simply rewriting Directory2 to Directory3:

FROM:

http://ourdomain.com/newsletters/Directory2/some-article.aspx

TO:

http://ourdomain.com/newsletters/Directory3/some-article.aspx

Perhaps I am thinking way too hard about this. I need to try and preserve everything EXCEPT for the directory after /newsletters/. I can't just pass:

http://ourdomain.com/newsletters/Directory3/[HTTP::uri]

as this would duplicate part of the URI making it look like this:

http://ourdomain.com/newsletters/Directory2/newsletters/Directory3/some-article.aspx

So that's why I'm a bit confused....Do I need to perform some sort of scanning using the URI basename, or simply rewrite based on the URI::path?

I appreciate any help!

joe_pipitone · Answer

I think I've got it - I simply used a string map, and incorporated HTTP::redirect vs HTTP::path as to perform the rewrite / redirect.

when HTTP_REQUEST {

Check if path starts with /newsletters/Directory2

if {[HTTP::path] starts_with "/newsletters/Directory2"}{

Replace /newsletters/Directory2 with /newsletters/Directory3 in the path

HTTP::redirect [string map {/newsletters/Directory2 /newsletters/Directory3} [HTTP::path]]

}

jrahm · Answer

So with something static like /newsletters/ beginning your URI, you could do a string range (in tlcsh):

set x "/newsletters/Directory2/something/else/entirely/file.txt"
puts "/newsletters/Directory3[string range $x [string first / $x 13] end]"

/newsletters/Directory3/something/else/entirely/file.txt

jrahm · Answer

so in iRules, that would be

HTTP::uri "/newsletters/Directory3[string range $x [string first / $x 13] end]"

might need tweaking if not as static as you presented in the request, but gets you along the way...

joe_pipitone · Answer

For some reason, when I start adding on string tolower, I keep getting redirect loops.  I want to be sure I catch any case in the browser and set it to lowercase - any idea what I may be missing here? 
  
 when HTTP_REQUEST { 
  
   Check if path starts with /newsletters/directory2 
    if { [string tolower [HTTP::path]] starts_with "/newsletters/directory2"}{ 
  
        Replace /newsletters/directory2 with /newsletters/directory3 in the path 
       HTTP::redirect [string map {/newsletters/directory2 /newsletters/directory3} [HTTP::path]] 
    }
 }

joe_pipitone · Answer

OK - I think I got it again - unless someone sees a problem with this performance wise: 
  
 when HTTP_REQUEST { 
  
   Check if path starts with /newsletters/directory2 
    if { [string tolower [HTTP::path]] starts_with "/newsletters/directory2"}{ 
  
        Replace /newsletters/directory2 with /newsletters/directory3 in the path 
       HTTP::redirect [string map {/newsletters/directory2 /newsletters/directory3} [string tolower [HTTP::path]] ] 
    }
 }

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