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Ben_Nichols_107's avatar
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Mar 28, 2012

RegEx assistance for compression URI list

Apologies if this is a basic question.





Ive been asked to configure a client's F5 to compress specific file type only for a particular site. They have a single virtual server that multiple sites are published through (using host headers on the web servers). The virtual server has an http profile that enables content compression for application/json. Ive now been asked to enable compression for *.aspx, *.js and *.css but only for one specific site that is published through the virtual server (dont ask me why, this is what I have been asked to do).



I was hoping to add entries like the following to the URI include list:













I cant work out the required format of regular expression. Or am I being dumb on this occasion?



My only other solution would be to create a new virtual server on a seperate IP, but I want to avoid that. Or I guess there are iRules, but I thought this would be simple.




Many thanks in advance.






1 Reply

  • Hi Ben,

    I think the URI list for compression only includes the URI--not the hostname. So you might need to use an iRule for this to selectively enable or disable compression using COMPRESS::enable|COMPRESS::disable. You could test this with just the profile first. The syntax for the URI list is regex, so you could try www\.sitename\com/.*\.aspx and www\.sitename\com/.*\.js. If either of those work, you could try setting the matching to be case insensitive: (?i)www\.sitename\com/.*\.aspx

    If you do need an iRule to implement your logic, here's something you could start testing with. You may need to tweak the logic, but hopefully the major pieces are there to start with.

    when HTTP_REQUEST {
     Save the path (/path/to/file for for comparison in the response
    set path [HTTP::path]
     Save the host 
    set host [string tolower [HTTP::host]]
    when HTTP_RESPONSE {
     Check if this is a text or application/json response
    switch -glob [string tolower [HTTP::header Content-Type]] {
    "text/*" -
    "application/json*" {
     Parse the filetype from the requested path
     Split off file.ext from /path/to/file.ext
     Then use findstr to parse the characters after a period
    set filetype [string tolower [findstr [URI::basename $path] . 1]]
    if {$filetype ne "" and $host eq ""}{
    switch $filetype {
    aspx -
    js {
     Enable compression
     Exit the iRule so we do not disable compression below
     If we have not enabled compression above, disable it explicitly here