unlike sendmail, recvmail is always optional. this is the case because
the cloudron may not receive emails at all, so app always has to be
prepared for it.
part of #804
There are two main use cases:
* A consultant/contractor/external developer is given access to just an app.
* A "service" personnel (say upstream app author) is to be given access to single app
for debugging.
Since, this is an "app admin", they are also given access to apps to be consistent with
the idea that Cloudron admin has access to all apps.
part of #791
Various notes on mounting:
* The permissions come from the mounted file system and not the mount point.
This means that if we change the perms before mounting, it is overridden by
whatever is in the actual file system.
* uid/gid only works for permission-less file systems
SFTP container notes:
* Assumes that nothing changed if the host path hasn't changed. This means that
if a user changes the disk uuid, reload doesn't work.
* Not sure how/why, but even after unmounting the container can still access the old
mount files (!). With ext4 on disk change or nfs after root path change, the file manager
continues to be able to access the old mounts (despite umount succeeding).
All this led to following changes:
* Remove editing of volumes. Just allow editing username/password.
* edit UI then just also provides a way to re-mount.
* Change mode of mountpoint to be 777 post mounting for ease of use. Otherwise, we have to
make the user do this by ssh. this can always become options later.
notifications are now system level instead of user level.
To clarify the use events/notifications/email:
* eventlog - everything that is happenning on server
* notifications - specific important events (alerts)
* email - these are really urgent things that require immediate attention. this is for
the case where an admin does not visit the dashboard often. can also be alerts like
bad backup config or reboot required which are not events per-se.
Notes on notifications
* oom - notification only
* appUpdated - notification only
* cert renewal failure - only raise when < 10 days to go. also send email thereafter (todo).
* Backup failure - only if last 5 backups failed (todo).
* Box update - notification only. we anyway send newsletter.
* box update available - we raise a notification. no email.
* app update available - we already have update indicator on dashboard. so, no notification or email.
Alerts:
* backup config
* disk space
* mail status
* reboot
* box updated
* ubuntu update required
