Help me with redirect and match cases, please

Kenny,

the correct syntax is:

if (tolower(http_uri) contains "logon") {
   redirect to "https://%h/%u"
}
else {
   discard
}

The tolower(string) function returns lowercase version of the string you pass it as argument. It does not change the original string. It does not interfere with redirection in any way. Keep in mind though that the URI expanded in place of the %u in the redirect string will have the original capitalization. If you want to insert lowercase version of the URI into the redirection string you need to use:

redirect to "https://" + http_host + tolower(http_uri)

The test on server_port == 80 is redundant if you attach the rule to a port 80 virtual server, like this:

virtual 1.2.3.4:80 {
   use rule your_rule
}

(the server_port is always going to be 80 in this case)