Use /var/lib/homeassistant as Supervisor data directory

[agners]

Instead of using /usr/share/hassio use /var/lib/homeassistant as Supervisor data directory. While the Supervisor data directory is a mixed bag of user and somewhat static files, /var/lib seems the better fit than /usr/local.

Fixes: #393

[ikifar2012]

@agners while I do agree with this change I noticed when upgrading on a fresh machine created today from the previous version it does not retain any data. Do you think we should handle migration or just warn the user? I am a bit afraid of handling the migration automatically as we don't know how every user could have their system configured but I also think users really need to be made aware of the changes as it could result in panic if their configuration is gone

[agners]

@agners while I do agree with this change I noticed when upgrading on a fresh machine created today from the previous version it does not retain any data. Do you think we should handle migration or just warn the user? I am a bit afraid of handling the migration automatically as we don't know how every user could have their system configured but I also think users really need to be made aware of the changes as it could result in panic if their configuration is gone

Uh I see, we overwrite the config unconditional, so if the user does not set an explicit DATA_SHARE environment variable, it will default to the new location even on upgrade.

That was not my intention. Fixed it now by reading the json config file if it is present. Right now, even if the user provides a DATA_SHARE, we'll retain the old value. I think if the user wants to move the data directory, he'd have to manually move the data and adjust the config afterwards.

[ikifar2012]

@agners while I do agree with this change I noticed when upgrading on a fresh machine created today from the previous version it does not retain any data. Do you think we should handle migration or just warn the user? I am a bit afraid of handling the migration automatically as we don't know how every user could have their system configured but I also think users really need to be made aware of the changes as it could result in panic if their configuration is gone

Uh I see, we overwrite the config unconditional, so if the user does not set an explicit DATA_SHARE environment variable, it will default to the new location even on upgrade.

That was not my intention. Fixed it now by reading the json config file if it is present. Right now, even if the user provides a DATA_SHARE, we'll retain the old value. I think if the user wants to move the data directory, he'd have to manually move the data and adjust the config afterwards.

Awesome, just tested, works great... I'm gonna merge!