alpine has different User IDs for the user www-data.
This means, that if you switch to the alpine image, the owner and permissions of the directory /var/www are incorrect.
You need to execute the following command manually to correct this:
docker exec nextcloud_app_1 chown -R www-data:root /var/www (replace "nextcloud_app_1" with your actual app container)
After that, restart the container and the permission errors should disappear.

Make sure that you have the most current "nginx.conf" for your alpine image, otherwise your container will not start with an error... (the first line should NOT be user www-data;!)

Thank you! This worked. Perhaps this should be added as documentation somewhere.

@pera could you write down your steps and submit a pr?

The steps are exactly the same as #601 (comment). I can submit a pr, but I don't know where this sort of documentation goes. There isn't an explicit category for this sort of thing. Maybe a new category with important breaking changes should be created where breaking is defined as anything that breaks if you do a git pull in your local install.

The since added Migrating an existing installation section could probably hold this info under a sub-section.

@joshtrichards
Is adding this information still missing from the Migrating an existing installation section?
You can assign me the issue and I will create a pull request for this issue.

This Issue is still open and it doesn't appear there... So yes.

But there is no need to assign the issue. If you do create a PR, just link it to this issue.

Thanks!

PR #2289