Add option to ignore flows

[balloob]

Description:

Add option to create "ignored" config entries. Can be created based off any config flow in progress that have a unique ID set. Includes websocket API for this too.

Hue has been updated to still show the ignored hosts as options to configure when starting a manual configuration.

Config entry that is ignored will not be set up and thus not be passed to async_setup_entry.

@bramkragten will work on a UI piece for this.

Only config flows that have unique IDs can be ignored. Since it depends per integration on what is a unique ID, we can't automatically fill this in. Each integration needs to add it themselves. Example of Hue inside ssdp and homekit:

https://github.com/home-assistant/home-assistant/blob/58b5833d64cd66401d313206595ce582125f8f9f/homeassistant/components/hue/config_flow.py#L167-L168

Calling self.async_set_unique_id will by default abort the current config flow if another config flow is already in progress. To abort if the unique ID is part of a config entry, call self._abort_if_unique_id_configured().

I am not 100% sure yet if this is the right abstraction or that we can move the "abort if in progress" part to the self._abort_if… call. I'll revisit this pattern if a few more config flows are updated.

Builds on top of #29806 and #30000.

CC @Jc2k

Related issue (if applicable): fixes home-assistant/architecture#250

Pull request with documentation for home-assistant.io (if applicable): TBD

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.
• I have followed the development checklist

If the code does not interact with devices:

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

[probot-home-assistant]

Hey there @home-assistant/core, mind taking a look at this pull request as its been labeled with a integration (config) you are listed as a codeowner for? Thanks!

[Jc2k]

@balloob Looking good! I’ve pushed a branch to my github that adds async_set_unique_id to homekit_controller, will try and finish this off ASAP.