Are you using Let's Encrypt?
If so you might be interested in acme-tiny. It is a 200 lines of code client to handle the installation and renewal of your LE SSL certs.
There is a one-time requirement to convert the account_key from JWK to PEM. After that everything can be automated through scripts & cron.
I like that acme-tiny is: standalone, small & so easy to review. Installable via Pip, apt-get and probably other package managers.