Feature request: support for --insecure during apptainer push and pull

[anderbubble]

apptainer pull uses HTTPS by default. HTTPS can be disabled with --no-https; but in circumstances where HTTPS is desired but a self-signed certificate is in use, we would like to be able to use --tls-verify=false or similar.

If this is already possible with an environment variable, that would be fine; but I haven't been able to find such an option.

[DrDaveD]

I suggest an --insecure option to be like curl. It would need to be on pull, build, action commands run/start/exec, and instance start/run. There is already an option by that name on remote add although the description says it applies to only http, not https. I would think that should be extended to https if it isn't already, or the description changed if it already includes https.