Well, it’s not exactly ignition doing it but related to it (the option comes via the ignition config): os/overlay.d/05rhcos/usr/lib/dracut/modules.d/40rhcos-fips/rhcos-fips.sh at c248ce256df8573f5499c4f9bdb2fd29eb4bdcef · openshift/os · GitHub
We’ve been looking at fully integrating it in ignition: Add `fips: true` · Issue #1323 · coreos/ignition · GitHub