Where is Rsyslog programname set?

I am using AWS Elasticbeanstalk to run my java web application. In EC2 node under /etc/rsyslog.d/web.conf

if $programname  == 'web' then {
    *.=warning;*.=err;*.=crit;*.=alert;*.=emerg /var/log/web.stderr.log
    *.=info;*.=notice /var/log/web.stdout.log
  }

I get what is being done. but I did not get where the $programname is set as web. if i want to create my own programname and redirect logs to different file, how to do it?