Let's Encrypt Server Load for @daily crons

[jamessqr]

Description of problem

Recently Let's Encrypt has noted increased server loads at 00:00:00 https://community.letsencrypt.org/t/new-service-busy-responses-beginning-during-high-load/184174/2

We discovered a Dokku instance has been failing letsencrypt renewal for approximately a month using the dokku-letsencrypt plugin. Reviewing the cron log we were receiving the 503 errors and various outage type responses from Letsencrypt. We manually changed the cron task to a different time of the day and things are working.

I suggest an enhancement to dokku-letencrypt to allow a custom cron expression when the jobs are added so that everyone using the plugin isn't ddos'ing their servers

[roelvanduijnhoven]

I've observed the same thing.

To make the change manually you can do the following. Run crontab -e -u dokku to open the relevant cronfile in your default configured IDE. And apply a patch like below.

PATH=/usr/local/bin:/usr/bin:/bin
SHELL=/bin/bash

-@daily dokku letsencrypt:auto-renew &>> /var/log/dokku/letsencrypt.log
+30 3 * * * dokku letsencrypt:auto-renew &>> /var/log/dokku/letsencrypt.log

[josegonzalez]

I've opted to just change our default time for now.