Breeze: bind api-server dual-stack so http://localhost works in Chrome/Safari

[pierrejeambrun]

Summary

breeze start-airflow launches airflow api-server with no --host override, so it picks up the default [api] host = 0.0.0.0 — IPv4 only. On macOS with OrbStack (and any other dual-stack-forwarding runtime), this breaks http://localhost:28080 in Chrome and Safari but not Firefox — a confusing failure mode hidden behind an opaque chrome-error://chromewebdata/... page.

This change makes the breeze-spawned api-server bind :: (the IPv6 wildcard), which on Linux/macOS dual-stack sockets accepts both IPv4 and IPv6 connections. One-line behavior fix; no public Airflow config changes.

Why this happens

• macOS /etc/hosts resolves localhost to both 127.0.0.1 (A) and ::1 (AAAA).
• Chrome / Safari prefer the IPv6 address — they try [::1]:28080 first.
• OrbStack binds the host-side port-forward dual-stack: OrbStack ... TCP *:28080 (LISTEN) on both IPv4 and IPv6. The IPv6 TCP handshake therefore succeeds at the host…
• …but the api-server inside the container is bound to 0.0.0.0 only, so there's no listener on [::]:8080. The container responds with TCP RST.
• The browser then renders chrome-error://chromewebdata/ and emits the misleading "Unsafe attempt to load URL ... from frame with URL chrome-error://chromewebdata/" console message.
• Firefox prefers IPv4, so it hits 127.0.0.1:28080 and never sees this. Docker Desktop historically only forwards IPv4, so happy-eyeballs falls back cleanly to IPv4 there too. The combo of Chrome + macOS + OrbStack is what surfaces it.

Reproduce (before this patch)

breeze start-airflow
curl -v http://localhost:28080/        # → Recv failure: Connection reset by peer
curl -v http://127.0.0.1:28080/        # → 200 OK
# open http://localhost:28080/ in Chrome  → chrome-error page
# open http://localhost:28080/ in Firefox → works

After this patch

The api-server binds dual-stack inside the container, so localhost reaches it regardless of which family the browser picks.

Was generative AI tooling used to co-author this PR?

• Yes — Claude Code (Opus 4.7)

Generated-by: Claude Code (Opus 4.7) following the guidelines

[github-actions]

Backport successfully created: v3-2-test

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
✅	v3-2-test

[jroachgolf84]

This actually broke my setup. I'm using Orbstack and Safari, and I get a blank page when trying to navigate to localhost:28080. I have a backdoor way around this for now.