step isn't used for anything yet

No need to cram this into v15.0.0.

I also lack background for this change, it seems. What's the rationale here?

I also lack background for this change, it seems. What's the rationale here?

For step? I explained this in the "changes" list regarding it.

I think it's a more user friendly openssl alternative that we can use for both TLS/X.509 certs and public-key cryptography (DKIM/ARC). It'd be useful for docs, troubleshooting advice (nicer output vs openssl, can output results as JSON too), self-signed cert and key generation.

As such it can replace the separate opendkim/rspamd DKIM key generators. Your rspamd script for example appears to start rspamd in the background just to generate the keys.

We could technically not add step into the image, but given the image already weighs over 700MB, 13MB isn't a big ask for the convenience to users and our docs.

Or were you asking about the other changes unrelated to step? Those should also be explained under the "changes" list I provided?

Sorry, I was blind I guess... I somehow missed it in the PR description.

I really like these modern tools! And I also appreciate this replacing the horrible openssl command ❤️👍🏼

LGTM 👍 If there are more tools in the future, we should put them in own functions.

IMO we can put this into v15.0.1 too @polarathene if you update CHANGELOG.md.