cronic auto-renew for certbot

cronic now restarts services.

 Automatic certificate renewal is useless if the services that use the certificate are  not restarted.

to have a service restarted after the certificate is renewed,
use the "--restart" switch with the service command to be
restarted in quotes.
example:

    ./cronic --restart "/usr/sbin/nginx -s reload"

restart commands can be added anytime, whether or not
the certificate is renewed.

restart commands only need to be added once.

the restart command will be run everytime a certificate is renewed.

to remove a restart command:

        crontab -e

delete the line containing the command you wish to remove.

I am a HUGE fan of certbot.

I have always had a problem with companies charging hundreds of dollars for certs, and I used to self sign certs for my mail servers, and that is a huge pain in the ass. My only issue is that I often forget to renew my certs in a timely manner. I've been using this for a couple of years and haven't even thought about my certs until just recently when I deployed a new OpenBSD mail server, I ran certbot got my cert, ran cronic and set a cron job, and I'm done.

certbot says:

cronic does it differently.

• cronic uses the certificate notAfter date to determine when to renew.
• renewal is scheduled for 5 days before certificate notAfter date.
• After the certificate is renewed, cronic automatically sets the next cron job.
• cronic has automatic Let's Encrypt certificate discovery.
• cronic support multiple certificates with different renewal dates, on the same server.

cronic conditionals

• You can run cronic manually at any time, it won't break itself.

• These are the conditioals used by cronic.

• If the cert is NOT ready renewal:

  • let's encrypt is not contacted.
  • Cron job installed to valid renewal time.
  • crontab displayed.

• If the cert is ready for renewal:

  • cert is renewed.
  • cron job created for next renewal at valid renewal time.
  • crontab displayed.

• If the renewal process fails and renewal cannot be attempted:

  • error messages printed.
  • new cronjob installed for four hours later.
  • crontab displayed.

• Of course it runs on OpenBSD.

• Also tested on Debian Sid.

cronic Requirements

1. Python 3.6+
2. openssl
3. Any UNIX or Linux system using cron.
4. certbot

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Install cronic

1. git clone the repo git clone https://github.com/superkabuki/cronic
2. chmod cronic/cronic chmod +x cronic/cronic
3. as root, run it. cronic/cronic
4. run it once and you're done.
   • It doesn't matter if you cert is up for renewal or not, cronic will handle it.
   • It doesn't matter how many certs you have, cronic will handle it.

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