Advertise dashboard over mDNS in HA addon mode

[bdraco]

What does this implement/fix?

The dashboard now advertises itself over mDNS when running as a Home Assistant addon, so the ESPHome Desktop app can discover that a builder is running on the network. Previously the advertise was skipped entirely in addon mode.

The addon runs with host networking, so the announce carries the host LAN IP and reaches peers. The one wrinkle is that the container also sees the Supervisor hassio bridge (172.30.32.0/23); that address is host internal, so it is now filtered out the same way docker0 already was, and we never advertise an unreachable 172.30.32.x address.

The advertise is discovery only; the peer-link receiver stays default off on the addon, so the announce carries server_version and esphome_version but no pin_sha256 or remote_build_port. The companion frontend PR uses that absence to hide the addon dashboard from the send builds list, since it cannot accept builds.

Related issue or feature (if applicable):

• No related issue

Types of changes

• Bugfix (non-breaking change which fixes an issue) — bugfix
• New feature (non-breaking change which adds functionality) — new-feature
• Enhancement to an existing feature — enhancement
• Breaking change (fix or feature that would cause existing functionality to not work as expected) — breaking-change
• Refactor (no behaviour change) — refactor
• Documentation only — docs
• Maintenance / chore — maintenance
• CI / workflow change — ci
• Dependencies bump — dependencies

Frontend coordination

• No frontend change needed
• Companion frontend PR: Hide unbuildable dashboards from Known Dashboards device-builder-frontend#743

Checklist

• The code change is tested and works locally.
• Pre-commit hooks pass (ruff, codespell, yaml/json/python checks).
• Tests have been added or updated under tests/ where applicable.
• components.index.json / definitions/components/*.json have not been hand-edited (regenerate via script/sync_components.py if a sync is needed).
• Architecture-level changes are reflected in docs/ARCHITECTURE.md and/or docs/API.md.

[codspeed-hq]

Merging this PR will not alter performance

✅ 27 untouched benchmarks
⏩ 1 skipped benchmark¹

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_{Comparing make-dashboard-discoverable-in-addon (aba4da7) with main (ba5b85d)}

Footnotes

1. 1 benchmark was skipped, so the baseline result was used instead. If it was deleted from the codebase, click here and archive it to remove it from the performance reports. ↩

[esphbot]

PR Review — Advertise dashboard over mDNS in HA addon mode

Focused, well-tested change — merge-ready.

• Removes the addon-mode advertise guard cleanly; the rationale (host networking carries the real LAN IP) is captured in the updated comment.
• hassio added to the virtual-bridge prefix list so the Supervisor 172.30.32.0/23 address never reaches the wire, mirroring the existing docker0 filtering.
• Test coverage is solid: new test_local_addresses_ha_addon_layout exercises the realistic host-networking adapter mix, and the addon-mode advertise test was correctly inverted (now asserts construction + register await).
• One minor suggestion: the Supervisor range is suppressed by interface name only; an IP-subnet guard would be a cheap backstop, but the name match is consistent with prior art and not blocking.

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Automated review by Kōan (Claude) HEAD=b5dc1e3 1 min 5s

[esphbot]

No blocking issues found.

[Copilot]

Pull request overview

This PR enables the backend to advertise the Device Builder dashboard over mDNS when running as a Home Assistant add-on, allowing LAN discovery (e.g., by ESPHome Desktop) in add-on deployments. It also avoids advertising host-internal Supervisor networking addresses by filtering the hassio bridge interface out of the address selection used for announcements.

Changes:

• Remove the HA add-on guard that previously skipped dashboard mDNS advertising, so advertising occurs whenever zeroconf is available.
• Filter the HA Supervisor hassio bridge interface from _local_addresses() so announcements don’t publish unreachable 172.30.32.0/23 addresses.
• Extend unit/integration tests to cover the add-on network layout and the “advertise in add-on mode” behavior.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
tests/test_dashboard_advertise.py	Adds HA add-on bridge filtering coverage and updates the DeviceBuilder lifecycle test to expect mDNS registration in add-on mode.
esphome_device_builder/helpers/dashboard_advertise.py	Treats hassio* interfaces as virtual bridges so their addresses are excluded from advertised A/AAAA records.
esphome_device_builder/device_builder.py	Advertises the dashboard in HA add-on mode when zeroconf is available, instead of skipping unconditionally.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.49%. Comparing base (ba5b85d) to head (aba4da7).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1367      +/-   ##
==========================================
- Coverage   99.49%   99.49%   -0.01%     
==========================================
  Files         221      221              
  Lines       16991    16989       -2     
==========================================
- Hits        16906    16904       -2     
  Misses         85       85              

Flag	Coverage Δ
py3.12	99.47% <ø> (-0.01%)	⬇️
py3.14	99.49% <ø> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
esphome_device_builder/device_builder.py	97.73% <ø> (-0.02%)	⬇️
...home_device_builder/helpers/dashboard_advertise.py	100.00% <ø> (ø)

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