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How can LED trigger NC sensor?

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I have a RAID card for my server which doesn't communicate to OS when there is a drive failure.

I would like to detect when the 'health' led is active and have it trigger an NC contact on my Caddx security system.

I thought of 2 ways to do this, one hacky and one not.

Non-hacky way: Design circuit off of led pins which wires straight into alarm zone/common terminals.

Hacky way: Run a photodiode into small project box with the LED at other end of box. When LED lights...sensor is triggered. I guess this is what they call an opto-isolated input?

I'm a software guy and no zip about electronics. Help would be appreciated greatly.
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You can just use an optocoupler from your existing led and have that trigger the relay.
The optocoupler is virtualy what you just said but all in one package.
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