Forum Discussion
Jakov_40007
Nimbostratus
NimbostratusHTTP::path and HTTP::query question
I am new to iRules and having difficulty writing a rule that will rewrite a request from the client to a server by replacing the 'path' but will still retain the query string that follows. I have written the following rule, and it seems to be working fine for rewriting the path, but in the process the query string gets lost and never makes it to the server.
when HTTP_REQUEST {
if { [string tolower [http::host]] equals "www.abc.com" } {
if { [http::path] equals "/"} {
http::path "/en-CA/default.htm"
return
}
}
In this case, if I browse to http://www.abc.com/?xyz=8 what is reaching the server is http://www.abc.com/en-CA/default.htm, but the query (in this case 'xyz=8') gets stripped off. What I need it to do is send http://www.abc.com/en-CA/default.htm?xyz=8 or whaever the query value may be.
Thanks!
hoolioCirrostratus
It looks like your rule should work to rewrite just the path (and preserve the query string). Can you add some logging to check?when HTTP_REQUEST { log local0. "[IP::client_addr]:[TCP::client_port]: Original [HTTP::method] request to [HTTP::host][HTTP::uri]\ with path [HTTP::path] and query [HTTP::query]" if { [string tolower [HTTP::host]] equals "www.abc.com" } { if { [HTTP::path] equals "/"} { HTTP::path "/en-CA/default.htm" } } } when HTTP_REQUEST priority 501 { log local0. "[IP::client_addr]:[TCP::client_port]: Current: [HTTP::method] request to [HTTP::host][HTTP::uri]\ with path [HTTP::path] and query [HTTP::query]" }
The second HTTP_REQUEST event allows you to log any changes without having any problems with cached HTTP command output.
Aaron
Jakov_40007Hi Aaron,
Strangely the log shows no query:
174.112.44.70:1713: Original GET request to www.abc.com/?me=8 with path / and query
Thanks,
Jakov- Jakov_40007I added the log both inside and outside the rule, and here is what I get both inside and outside the rule now. Not sure why it came back as blank query before.
Rule CWNA_S_HTTP_rule : 174.112.44.70:1982: Original GET request to www.abc.com/?me=8 with path / and query me=8
Jakov - hoolioWhat does the second log line show? ie, is the change actually made to the path?
Aaron - Jakov_40007The second log shows no query:
Rule CWNA_S_HTTP_rule : 174.112.44.70:1992: Current: GET request to www.abc.com/en-CA/default.htm with path /en-CA/default.htm and query - hoolioThat seems like a bug. HTTP::path should only return or set the path in the URI without retrieving or modifying the query string. You could work around this using HTTP::uri instead:
when HTTP_REQUEST { Check if path is / if {[HTTP::path] eq "/"}{ Parse the URI into the path and query scan [HTTP::uri] {%[^?]?%s} path query Check if there was a query if {[info exists query]}{ Update path, preserving query HTTP::uri "/en-CA/default.htm?$query" } else { Update path without query HTTP::uri "/en-CA/default.htm" } } }
I'd also suggest opening a case with F5 Support on the possible bug with HTTP::path removing the query string. Which LTM version are you running?
Aaron - Jakov_40007Hi Aaron,
Your code above seems to be working and gets around the problem with HTTP::path. I called support and they seem to be in agreement that it is a bug and will be investigating.
We are on 10.0.1 code build 283.
Thanks for your excellent help on this!
Jakov - hoolioHi Jakov,
If/when you get a CR for this, could you reply with it for reference?
Thanks,
Aaron - Jakov_40007Hi Aaron,
For now I just have a case number: C655714
The engineer is reviewing qkview.
Thanks again!
Jakov