Dokku: Add command to manage docker container log truncation

[josegonzalez]

This can be as simple as automatically creating a logrotate file:

https://blog.birkhoff.me/devops-truncate-docker-container-logs-periodically-to-free-up-server-disk-space/

And having this enabled/disabled via a global environment variable (DOKKU_LOGROTATE). If there is no value set, it is implied true. If it has a value of false, we delete the file. If it is set to true, we create the file. The value can be set via logs:set, and is output to logs:report.

On install of dokku, we'll set this value if it is not set.

[josegonzalez]

Hmmm maybe instead of making it togglable, I'll just set it as default.

[anentropic]

Would dokku be subject to the default settings described here?
https://docs.docker.com/config/containers/logging/local/

i.e. 100MB per container (20MB max-size * 5 files)

[josegonzalez]

Yep, we are just a - very! - thin docker wrapper. Any default settings you've set on the daemon will apply (in addition to custom docker-options).