Thanks for sharing your milage to success on adding two interfaces to OCI images.
I struggled with this a few times and have taken different approaches due to not existing features in Incus 6.3 at the time been. Since than a lot of things have changed / improved. Your solution encounters me to revisit my setup the next time I rebuild my OCI images.
Nowadays I would properly play around with providing my own init script to perform all the things by using the OCI entrypoint configuration which came with 6.11:
incus config show nginx | grep oci\\.
oci.cwd: /
oci.entrypoint: /docker-entrypoint.sh nginx -g 'daemon off;'
oci.gid: "0"
oci.uid: "0"
I would use normal apt calls to install required packages, cleanup all temp files / cache etc, bring the interface up like you did.
Alternative way might be to just mount the script into the right location. Yes, you can just mount files with Incus host into the instance.
Is a bit cleaner, simplify the whole process and might not require a storage volume at all.
Again your milage varies on what you want to archive…
Thanks again for sharing