Replace string using stream profile from backend server to client

Hi,

you can try this irule. the stream commands are in variable to support disabling stream profile and manage only 30X redirects.

rewriting try to convert absolute URL to relative URLs if the public URL is based on the service requested.

when RULE_INIT {
    unset static::rewrite_table
    array set static::rewrite_table {
        "https://www.company.com"   "http://srv-internal.company.local"
        "https://www2.company.com"   "http://srv-internal2.company.local"
    }
    set static::rewrite_table_map [list]
    set static::rewrite_table_stream [list]
    foreach item [array names static::rewrite_table] {
        lappend static::rewrite_table_map $static::rewrite_table($item)/ $item/ $static::rewrite_table($item) $item/
        lappend static::rewrite_table_stream "@$static::rewrite_table($item)/@$item/@"
    }
    log local0. $static::rewrite_table_map
    log local0. $static::rewrite_table_stream
     create stream commands in variables to run them only id stream profile is enabled
    set static::stream_disable "STREAM::disable"
    set static::stream_enable "STREAM::enable"
     change stream expression to convert current site response to relative URI.
    set static::stream_expression "STREAM::expression \[string map \"\$req_proto://\$req_host/ /\" \$static::rewrite_table_stream\]"
}

when CLIENT_ACCEPTED {
     set default protocol to http. change it to https if clientssl profile is assigned to the VS.
    if { [PROFILE::exists clientssl] == 1} {
        set req_proto "https"
    } else {
        set req_proto "http"
    }
    set stream_profile_enabled [PROFILE::exists stream]
}

when HTTP_REQUEST {
     Capture request hostname
    set req_host [HTTP::host]
    if {$stream_profile_enabled} {
         Disable the stream filter for all requests
        eval $static::stream_disable

         LTM does not uncompress response content, so if the webserver has compression enabled
         we must prevent the server from send us a compressed response by changing the request
         header that indicates client support for compression (on our LTM client-side we can re-
         apply compression before the response goes across the Internet)
        HTTP::header remove "Accept-Encoding"
    }
}

when HTTP_RESPONSE {
    if { [HTTP::status]  matches "30?"} {
         This is a 302 redirect with a absolute Location URI
        HTTP::header replace Location [string map [string map "$req_proto://$req_host/ /" $static::rewrite_table_map] [HTTP::header Location]]
    } elseif {[HTTP::header value Content-Type] starts_with "text"} {
         Apply stream expression stored in RULE_INIT event
        if {$stream_profile_enabled} {
            eval $static::stream_expression

             Enable the stream filter for this response only
            eval $static::stream_enable
        }
    }
}