Fix unique identifiers where multiple IKEA Tradfri gateways are in use

[cs12ag]

Resolving issue #134497

Proposed change

This PR fixes a bug whereby users with multiple Tradfri gateways configured in the Tradfri integration will see inconsistent / randomly changing lists of devices associated to those gateways in Home Assistant.

This PR also introduces a migration function within the init.py file, to correct installations where multiple gateways have been configured in the Tradfri integration. The migration script does two things:

• removes erroneously-added config-entry references from the associated device's 'config_entries' list; and
  • (this happens as a result of erroneously matching a device on gateway A using identifiers derived from gateway B using the current version of entity.py)
• updates the 'identifiers' of existing Tradfri devices in the device registry to be genuinely unique within the device registry, so that devices with clashing identifiers can be added as expected when initialising the integration (rather than erroneously updating an existing device).

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes IKEA TRADFRI integration appears unable to handle multiple gateways #134497
• This PR is related to issue: IKEA TRADFRI integration appears unable to handle multiple gateways #134497
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
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• Tests have been added to verify that the new code works.

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

• Documentation added/updated for www.home-assistant.io

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To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[joostlek]

So wait, what do you mean the problem is? Say I have 2 bridges. can the devices be used using both bridges (as in like a mesh?)?

Or are the device_ids just single numbers or so, first one gets 0, second 1, etc

[cs12ag]

@joostlek You can't have a single device paired to more than one gateway. The problem occurs in this HA integration when you try to use 2 or more Tradfri gateways, because of a combination of the way this integration was written and the way the Tradfri gateway firmware works.

In my specific example, the two gateways I've got have multiple devices associated to each of them. The pytradfri (not 100% name is correct) library responsible for polling the gateways simply responds with the list of unique identifiers that the gateway has assigned to each of its paired devices. My assumption is that because the gateways are the same hardware and firmware versions, they are using the same starting-point in the sequence used to assign unique IDs to devices as each device is paired to the gateway. Then, because of the code-issue seen (that this PR attempts to resolve), the devices are added to the device-library using the gateway's unique identifier with no other context. This has led to a situation whereby multiple devices in the device-library have identical identifiers, despite technically being different devices associated to different gateways. I have discovered that the devices will display in HA as the device associated to whichever gateway in the Tradfri integration that was most-recently (re)loaded.

Hopefully this example demonstrates the problem:
Gateway 1 has lamp with ID '1' paired to it.
Gateway 2 has switch with ID '1' paired to it.
There will be two separate devices in the device-library with the set of identifiers ['Tradfri','1'] on them. If I view the list of devices in this integration in the HA UI -
If I loaded gateway 1 most-recently in the integration, I'll only see the lamp device
If I loaded gateway 2 most-recently in the integration, I'll only see the switch device
I should be seeing both of the devices in the device list for this integration.

My guess is that when the original version of this integration was written, it was not tested with multiple gateways. My resolution is to add each gateway's own unique ID into the identifiers in the device-library, like ['Tradfri','gateway1-1']. The change corrects this going forward but I also wrote a migration method so that identifiers of all existing devices associated to the Tradfri integration were corrected and made unique, without having to delete the integration and its devices and start over.

Edit: realised I never at any point thanked you for taking a look, so - thanks! 👍

[home-assistant]

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[cs12ag]

To set expectations, I'll make changes over the next few days.

[cs12ag]

So I've attempted to upgrade the pytradfri dependency as part of this fix, and run into a bunch of issues as a result. I suspect there might be an issue with the pytradfri library: home-assistant-libs/pytradfri#986
I'll wait until I hear back on that issue before deciding how to continue here.

[cs12ag]

For this PR, the pytradfri dependency was restored to 9.0.1. There will be a forthcoming PR to change the tradfri component to support the latest version of pytradfri, as per home-assistant-libs/pytradfri#986

[MartinHjelmare]

Sorry, I noticed we didn't have coverage for some lines.

[MartinHjelmare]

Thanks!

[cs12ag]

Thanks for your help on getting this to completion @MartinHjelmare 👍

[MartinHjelmare]

Great work! 👍