Http to https without redirecting to client.

Not sure how this works, as I haven't used the "virtual" command in an iRule and really have no idea how it is handled internally, but give the following iRule a try. Apply this iRule to a non-http virtual server and create a second virtual server named VS_WITH_HTTPS (or anything you want to name it, really) and test it out.

when CLIENT_ACCEPTED {
  virtual VS_WITH_HTTPS
}