RFC: Deprecate auto target all for services and introduce entity_id: *

[balloob]

Description:

If entity_id is omitted, we currently target all entities. That's pretty dangerous and for any installation that has more than 1 room in Home Assistant, useless and sometimes dangerous (like triggering all automations 🙈).

This PR:

• introduces a new wildcard for entity_id to indicate you want to target all entity_id: "all".
• prints a warning if old method is used with target all

We should not add support in the future to add regex or partial wildcards as that will remove the ability to statically analyse the config. And this is not the PR to discuss this either, related comments will be marked as off topic.

Pull request in home-assistant.io with documentation (if applicable): TODO

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[MartinHjelmare]

Is step two, after deprecation period, to make entity_id required in all service schemas that target entity component services?

[balloob]

Yeah

[marchingphoenix]

Instead of * could we do ALL? Would remove the temptation of using it like a wildcard.

[balloob]

Updated to match on word "all"

[WedHumpDay]

Maybe outline what a end user should be looking for. Not all users are savvy and just search and tweak existing examples.

Here is an example automation script created and its generating the warning:

Warning Message
2019-01-10 13:59:00 WARNING (MainThread) [homeassistant.helpers.service] Not passing an entity ID to a service to target all entities is deprecated. Use instead: entity_id: "*"

Automation Script

- id: '1539091617090'
  alias: '----Test Dry Contact Sensor----'
  trigger:
  - entity_id: binary_sensor.visonic_mct340_e_0b110ced_1_1280
    from: 'off'
    platform: state
    to: 'on'
  condition: []
  action:
  - data:
      message: Test Door is Opened
      target:
      - Test_Cell
      title: ''
    service: notify.cell_phones
  - alias: ''
    data:
      volume_level: '.50'
    service: media_player.volume_set
  - alias: ''
    data:
      entity_id: media_player.living_room_2
      message: Test door is opened
    service: tts.google_say
  - timeout: '3'
    wait_template: ''
  - data:
      volume_level: '.25'
    service: media_player.volume_set

[balloob]

You're setting the volume of all your media players at the same time. You need to specify entity_id: all if you really want that.

Also please do not post in merged PRs.