Forum Discussion
CSA
Nimbostratus
NimbostratusAdding www. before HTTP::host / regexp matching
Hi,
We have today many websites like www.AA.domain.com where AA is a ccTLD (a country code). We want to have the websites working when users type AA.domain.com.
In the DNS, AA.domain.com is a CNAME to www.AA.domain.com.
I want to make the BigIP rewrite AA.domain.com to www.AA.domain.com
I did this but it doesn't work:
when HTTP_REQUEST {
if { [ string tolower [HTTP::host] ] matches_regex "(?:^\w\w\.domain\.com$)" } {
HTTP::redirect "http://www.[HTTP::host]/[HTTP::uri]"
}
}
Any idea why it doesn't work ? I don't find many doc about regexp in irules.
Many thanks,
CSAAnswering myself:
when HTTP_REQUEST {
if { [ string tolower [HTTP::host] ] matches_regex {^\w\w\.domain\.com$} } {
HTTP::redirect "http://www.[HTTP::host]"
}
}
Any remarks are welcome if I did something wrong.
HamishCirrocumulus
Hmm... Well, leaving aside the fact that you shouldn't have it as a CNAME (Because as a domain you'll have an SOA record plus maybe an MX record, and you shouldn't have any other records if you have a CNAME record). Best create it as an A record instead... Anyway...
IIUC what you're trying to do is if the host is NOT www.domain.com then do the redirect? Sorry, I'm not sure what regex syntax you're using there, but it doesn't look right... Wouldif {!(string tolower [HTTP::host]] equals "www.domain.com") } {
work just as well? If you just to to match when the host isn't www.domain.com? Using a regex for a simple match seems a bit overkill to me.
H- CSAHmm, I don't get what you mean when you say I shouldn't define CNAMEs. I don't have SOA or MX records on these entries, they are all in the domain.com zone, just standard A entries.
Your suggestion of irule will not work. I have many other DNS entries which doesn't look like AA.domain.com. - hoolio
Cirrostratus
How about a string pattern then?when HTTP_REQUEST { if {not [string match -nocase {[a-z][[a-z][.domain.com} [HTTP::host]] } { HTTP::redirect "http://www.[HTTP::host]/[HTTP::uri]" } }
Aaron - CSAI don't want anything.domain.com to be redirected to www.anything.domain.com.
Just 2 letters ccTLD. - hoolioHi Christophe,
The string match command (with the typo fixed) is equivalent to your regex:
% regexp {(?:^\w\w\.domain\.com$)} aa.domain.com
1
% regexp {(?:^\w\w\.domain\.com$)} aaa.domain.com
0
% string match -nocase {[a-z][[a-z].domain.com} aa.domain.com
1
% string match -nocase {[a-z][[a-z].domain.com} aaa.domain.com
0
Aaron - CSAI see...
I guess using string match is faster than the regexp one ?
Thanks for the suggestion BTW... - hoolioYes, the string match command is more efficient than the regexp by a factor of 10 in a simple tclsh test:
% time {regexp {(?:^\w\w\.domain\.com$)} aa.domain.com} 1000
20 microseconds per iteration
% time {string match -nocase {[a-z][[a-z].domain.com} aa.domain.com} 1000
2 microseconds per iteration
Aaron - CSAThanks!
Andrea_ArquintHi allHow do you run this command?
% regexp {(?:^\w\w\.domain\.com$)} aa.domain.com
Is this run on a linux bash shell???
I'm using centos and I did install "regexp" but there is no binary to execute???
Thanx for help
bb