Persist state across restarts

[Koenkk]

When zigbee2mqtt is restarted all cached states of the sensors are lost.

Zigbee2mqtt should persist the state to a file in the following way:

• Save the state to every 5 minutes.
• Save the state on exit.

Follow-up of #245

[tb-killa]

What about use the available devbox and build a own database with it?

[Koenkk]

@tb-killa dumping the JSON object is enough :)

@cmorlok @hoangtuit can you checkout the dev branch and check if it solves your problem?

[cmille34]

Is this getting close to becoming production? Retaining the values across reboots would help with some of the issues I've been annoyed with as well.

[Koenkk]

If you want to try it out you can use the dev branch for now.

[cmille34]

Is there a docker image with the dev branch? If not, any brief instructions on how I would use dev in a docker?

[Koenkk]

Yes, the -dev images.

[lolorc]

@Koenkk can it be configurable ?
when I restart zigbee2mqtt it sends all the persisted states. And it's not what I want at all, I really don't want to risk feeding mqtt with very old outdated states...

[Koenkk]

Would an option to disable this be enough? (in configuration.yaml)

[clockbrain]

Perhaps a specified time limit in configuration.yaml e.g. 60 (minutes)? On restart if saved state is within that limit it uses saved state otherwise it doesn't.

[lolorc]

@Koenkk an option would be great, so it could either be a boolean or a integer to specify the retention period as @clockbrain proposed. 0 could be no retention, 1 could be 1sec/min/hour...
but lastseen attribute would be needed to do the retention thing ;-)

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.