Need help on rewrite iRule

The external clients will hit the LTM with a own http host "x.y.com/EBC" and "x.y.com" we do need to "rewrite" this requests that the webserver understands it: "x.y.com/ebc".

firstly, here is short video explaining about HTTP::host and HTTP::uri.

5-Minute iRules: What's a URL? by Colin Walker

Do we need to use "string tolower" command in the beginning

there are several ways to change letter case. string tolower is a good choice when you want to change whole string no matter what the string is.

if you want to change specific string, string map might be a better choice.

e.g.

 configuration

[root@ve11c:Active:In Sync] config  tmsh list ltm virtual bar
ltm virtual bar {
    destination 172.28.24.10:80
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        http { }
        tcp { }
    }
    rules {
        qux
    }
    source 0.0.0.0/0
    source-address-translation {
        type automap
    }
    vs-index 8
}
[root@ve11c:Active:In Sync] config  tmsh list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:80 {
            address 200.200.200.101
        }
    }
}
[root@ve11c:Active:In Sync] config  tmsh list ltm rule qux
ltm rule qux {
    when HTTP_REQUEST {
  HTTP::uri [string map -nocase {/ebc /ebc} [HTTP::uri]]
}
}

 test1

[root@ve11c:Active:In Sync] config  ssldump -Aed -nni 0.0 port 80
New TCP connection 1: 172.28.24.1(39724) <-> 172.28.24.10(80)
1457248223.0429 (0.0026)  C>S
---------------------------------------------------------------
GET /Ebc HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Accept: */*
Host: x.y.com

---------------------------------------------------------------

New TCP connection 2: 200.200.200.14(39724) <-> 200.200.200.101(80)
1457248223.0470 (0.0018)  C>S
---------------------------------------------------------------
GET /ebc HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Accept: */*
Host: x.y.com

---------------------------------------------------------------

 test2

[root@ve11c:Active:In Sync] config  ssldump -Aed -nni 0.0 port 80
New TCP connection 1: 172.28.24.1(39725) <-> 172.28.24.10(80)
1457248251.3621 (0.0016)  C>S
---------------------------------------------------------------
GET /EBC HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Accept: */*
Host: x.y.com

---------------------------------------------------------------

New TCP connection 2: 200.200.200.14(39725) <-> 200.200.200.101(80)
1457248251.3639 (0.0015)  C>S
---------------------------------------------------------------
GET /ebc HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Accept: */*
Host: x.y.com

---------------------------------------------------------------

 test3

[root@ve11c:Active:In Sync] config  ssldump -Aed -nni 0.0 port 80
New TCP connection 1: 172.28.24.1(39726) <-> 172.28.24.10(80)
1457248276.1222 (0.0014)  C>S
---------------------------------------------------------------
GET /EBC/BHAbhaBHA HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Accept: */*
Host: x.y.com

---------------------------------------------------------------

New TCP connection 2: 200.200.200.14(39726) <-> 200.200.200.101(80)
1457248276.1239 (0.0015)  C>S
---------------------------------------------------------------
GET /ebc/BHAbhaBHA HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Accept: */*
Host: x.y.com

---------------------------------------------------------------