Add hook for script before requesting a new certificate

[vsund]

I'm using acme-dns as provider for DNS challenges and I'd like to start it when it's needed and stop it when it's not needed anymore (and additionally copying over certificates and restarting services).

For this various hooks would be great :) A few days ago there was a PR merged which adds a post hook. Are there any plans to add a pre hook too? (which e.g. would be executed when a certificate will get renewed)

[metanovii]

I join in ! And send some args to scripts via --hook , for eg domain name, date renew certificate and other.

[hari-govind]

I recently migrated from certbot and found this feature(--pre-hook) missing in lego. I can attempt a pull request for this.

[tengzl33t]

Will it be added someday? Would be nice to get something similar to this: https://eff-certbot.readthedocs.io/en/stable/using.html#pre-and-post-validation-hooks