podman's containers.conf `hosts_file` turns out to apply only to native
`podman run`; the Docker-compatible API ignores it, and the agent types
`docker`. (`base_hosts_file`, used before this, is a no-op in both
paths on podman 5.4.2.) So no config key can put the gateway name in a
nested container's /etc/hosts.
The name is therefore resolved in the bottle, where /etc/hosts does
carry it, and the address goes into the proxy URL handed to nested
containers. NO_PROXY keeps the name, since that is matched against what
a client asks for.
Verified on the macOS host: with the gateway reachable, a nested
container gets 200 from an allowlisted host and 403 from one that is
not — the egress boundary applies inside nested containers too.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
didericis
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