Don’t agree with either of the other answers.
It very much depends on what you mean by ethical?
For me, my chosen highest values are individual life and individual liberty, and that rapidly gets very complex.
Having individual life as value 1 means minimising risk to life – mine and everyone else’s.
Having liberty as value 2 means constraining my actions within the set of actions that minimise the risk to the life or liberty of everyone else.
If liberty is to have any real meaning, then it must be within interesting contexts.
Freedom to roam a sterile room isn’t nearly as interesting as roaming a world full of diverse social and ecological systems.
So part of maximising liberty is maximising the choices of contexts available (within the set that doesn’t pose undue risk to life or liberty).
All systems require boundaries to give them form. The more complex the system the more complex the boundary (as a general rule).
As we are the most complex thing we yet know of in this universe, our liberty must be within the sets of boundaries required for our existence. And that gets very complex with multiple overlapping sets of entities being present.
So for me – ethical means that set of actions that delivers on the values one has.
The classical ideas of right and wrong, good and bad, seem to be very low resolution models of systems that are (for the most part) vastly more complex than that. And some things do resolve down to reasonably close approximations. Killing people = bad. Restricting freedom without very sound reason = bad. Acting without due consideration of probable long term consequences = bad. Helping others in need = good. Accepting and respecting diversity = good. etc
And to be very clear, the idea of certain immortality is not a logical one.
The best one can hope for is indefinite life extension, as there is always a finite probability of death from things beyond the known. One cannot mitigate the risk of things we don’t know, and don’t know that we don’t know.
And for the most part, the historical record seems to indicate that such things usually occur at reasonably low frequencies, and should not be a major threat. And one can never be entirely certain about such things. The universe is a big and dangerous place for entities like ourselves.
And I am all for continuing to exist for as long as I possibly can, with expanding capabilities as I do so.
My understanding of evolutionary theory and games theory indicates clearly to me that the greatest probability of such continued existence is delivered by being as cooperative as possible with other cooperative agents (and not all agents are necessarily cooperative).