Purge recorder data by default

[amelchio]

Breaking change note:

Home Assistant now defaults to purge recorded history that is older than 10 days. If you want to keep your recorded data for longer than that, you must configure the number of days to retain before starting 0.64 for the first time, for example:

recorder:
  purge_keep_days: 30

If you want to keep the previous default of never deleting history, use this configuration:

recorder:
  purge_interval: 0

Description:

This is step 2 of the plan to purge recorder data by default. Step 1 was merged in #11976 with tweaks in #12220 and #12246.

The PR enables purge every ten days by default. This means that we can remove the explicit configuration from generated config that was introduced in 0.63.

The pre-0.64 behavior can be restored with this configuration:

recorder:
  purge_interval: 0

This can also be used to run the purging at predictable times, like at night:

recorder:
  purge_interval: 0

automation:
  - alias: "Purge database"
    trigger:
      platform: time
      at: '04:00:00'
    action:
      - service: recorder.purge

We always have a purge_keep_days value now so recorder.purge will default to using that.

Also, the recorder.purge service now supports an optional repack parameter that will do a vacuum for SQLite. I picked "repack" rather than "vacuum" or "optimize" (as it is called in MySQL) to get a generic word that does not sound too positive (because repacking can be pointless or even bad).

Pull request in home-assistant.github.io with documentation (if applicable): home-assistant/home-assistant.io#4643

Checklist:

• The code change is tested and works locally.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.github.io

If the code does not interact with devices:

• Local tests with tox run successfully.
• Tests have been added to verify that the new code works.

[amelchio]

I now added a documentation PR and a "breaking change note" so I believe this is good to go.

[balloob]

You only forgot the label :)