There have been a number of tickets in the past - most recently #7061 - covering the fact that Dokku doesn't clean up disk utilization. The underlying issue is that Docker uses build cache that cannot be cleaned up in a targeted way - and usually doesn't even respect the builder gc settings in a way that makes sense. In fact, the computed disk space does not line up with actual disk utilization, causing it to be a mystery to anyone investigating the underlying problem.
This change introduces a cron-based mechanism that cleans up disk once a day. Cleaning up more often would potentially cause issues during a build if for some reason the prune and an app deploy happened at the same time - its not clear if there is a lock on build cache usage - so cleaning up after hours once a day is a decent tradeoff.
In the future, this setting may be modifiable, but it works well for now.
Closes#7061
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.
[1]: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
In some cases, we might hold onto intermediate images until the next deploy. While these images are generally part of newer images - and are therefore cleaned up when the child images are no longer in use - they cruft up the 'docker image ls' output, causing some folks to believe Dokku is not cleaning up images.
Refs #6272
Previously, we would filter containers and images by name, which could be fail if the app was renamed or no longer was tagged "correctly" due to a rebuild. Now, we filter by label, ensuring an app is completely cleaned up on deletion.
Also:
- Move docker image cleanup from apps plugin to builder plugin: This isn't where it belongs - images should be cleaned up in a builder plugin (or the builders plugin) and not in the apps plugin, which has nothing to do with docker images anyways.
- Remove the code from the scheduler plugin, as that will only do anything if the scheduler is enabled for the app.
- Bypass image removal if there are no images to remove
- Always delete app containers: The herokuish builder creates intermediate build containers - something that should be refactored - and ideally this gets run in that builder plugin, but keeping the logic here ensures we don't have code duplication. This is otherwise safe as it will be a no-op if there are no containers to clean up.
Because the app-json extraction happens before the build-dir is set, it doesn't end up respecting the value, and thus the user might get the wrong app.json file.
This takes advantage of path.Join()'s default of ignoring empty paths.
