Hello out there!
I wish to make package self-initializing, dependent of the environment
(production / test)
Is following a good design pattern?:

Package body my_ftp
.....
ipnr varchar2(100);

-- some procedures and functions

begin -- begin block in package body!
if this_is_production then
ipnr := 'external.domain.com';
else
ipnr := 'internal.domain.com';
end if;
end; -- package end!

-----------------------------------------
The begin-block will only be executed the first time I use something in the
package in the session.

Greetings
Bjørn