shadowdaoandClaude Opus 5 5d16b5713d Give BuildKit the host's network, so it can reach the runner's cache ...

The multi-arch build needs the `docker-container` driver — the plain `docker`
driver cannot do linux/amd64+linux/arm64 — and that driver runs BuildKit in
its own container on Docker's default bridge. act_runner advertises
ACTIONS_CACHE_URL as an address the *job* container can reach, and nothing
teaches the BuildKit container about it. So the job could reach
192.168.1.126:40649 while the container actually making the cache request
could not.

That is also why no other workflow here hit this: it is the only one using
buildx. The rest make their cache calls from the job container act_runner set
up.

`no route to host` is EHOSTUNREACH — a firewall rejecting, not a missing route
— which is what a default firewalld zone does to traffic from the docker
bridge, and the runner registers under the stock RHEL/Fedora hostname.
Sharing the host's namespace sidesteps it: the cache address becomes local to
BuildKit. No effect on runners where this already worked.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0145mQi9NZiCDrznBUEEDE4n

2026-09-08 15:30:27 -07:00

..

workflows

Give BuildKit the host's network, so it can reach the runner's cache

2026-09-08 15:30:27 -07:00