This is the layer that actually decides it, and it was in the script
from the start: ~/.docker/config.json's proxies block is what the Docker
CLI copies into every container it starts. Being client-side it beats
the podman service outright, which is why containers.conf `env`,
http_proxy=false, and the service environment each looked correct on
disk and changed nothing a nested container saw.
Also corrects the comment on the service-env substitution, which
claimed to be the one place the address sticks. It is not; it covers
podman's own pulls and non-CLI API clients.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Third attempt at the same symptom, and the first at the right layer.
podman's Docker-compatible API injects proxy settings from the *daemon*
environment after containers.conf is applied, so neither the env list
(892bfc16) nor http_proxy=false (21c144ae) could override it — the same
compat-path blind spot already seen with hosts_file. Nested containers
kept reporting `wget: bad address 'bot-bottle-gateway:9099'` through
both.
Substituting the resolved address into the service's own environment,
before `podman system service` starts, is the one place it sticks.
NO_PROXY keeps the name, which is matched against what a client asks
for.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The address-bearing proxy URLs from 892bfc16 were written correctly but
never took effect: podman copies the host's proxy environment into every
container by default, and that copy overrides containers.conf `env`,
restoring the `bot-bottle-gateway` name a nested container cannot
resolve. Verified on the macOS host — containers still reported
`wget: bad address 'bot-bottle-gateway:9099'` with the addresses in
place.
Setting http_proxy=false disables only podman's own passthrough; the
proxy vars still reach containers, by address, from the env list.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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>
Answers the last open question in #392: DNS from inside a nested
container was not a phantom, but it was also not a DNS problem. Public
resolution fails there by design — everything egresses through the
proxy — and the actual breakage was two missing pieces:
- The proxy URL names `bot-bottle-gateway`, which resolves only through
the bottle's own /etc/hosts. Containers got their own hosts file, so
they failed at "Could not resolve proxy", which reads like broken DNS.
base_hosts_file propagates the bottle's entries.
- The gateway TLS-intercepts, so a container that does not trust the
bottle's CA bundle fails with "unable to get local issuer
certificate". The bundle is now mounted read-only and the usual env
vars point at it, which covers curl, wget, python, and node without
distro-specific trust commands.
Verified on the macOS host by reproducing each failure and confirming
that these three conditions applied by hand produced HTTP 200 from
inside a nested container. podman already forwards the proxy env, so
that needed nothing.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
netavark shells out to `nft` for the bridge network every compose file
expects, and aardvark-dns serves name resolution inside nested
containers. Neither arrives with the base image's
`--no-install-recommends` podman, and each fails at a different and
misleading layer: without nft containers are created but never start;
without aardvark-dns DNS inside a container fails while the engine, the
pulls, and the bridge all look healthy. That last one is the likeliest
explanation for the "DNS inside nested containers fails entirely" note
in #392 — a missing package, not a design gap.
Verified on the macOS host: with passt alone, `docker run` reached
netavark and died on "unable to execute nft".
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
podman 5 uses pasta as the default rootless network helper; podman 4
used slirp4netns. The spike was written against bookworm's podman 4.3.1,
so its package list never included passt — and the trixie bump (#451)
changed the default out from under it. Every nested container failed to
start with "could not find pasta", while image pulls and the service
itself worked, which disguised a missing dependency as a compat-API bug.
The bootstrap now checks for pasta up front so this fails with a clear
message instead of surfacing at the first `docker run`.
Note the sun_path fix in a12d2191 did NOT cause or cure this; that path
was over the 108-byte limit independently and would have bitten as soon
as attach was reached.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
podman derives conmon's attach socket as
`$XDG_RUNTIME_DIR/libpod/tmp/socket/<64-hex-id>/attach`. With the
descriptive `/tmp/bot-bottle-podman-run` that path is 116 bytes, past
the 108-byte sun_path limit, so every attached `docker run` failed with
"unable to upgrade to tcp, received 500" — while image pulls and the
service itself worked, which is what made it look like a compat-API bug
rather than a path-length one.
Found on the macOS host: quay.io pulled fine and then no container
could be started. Test pins the budget so a more readable name cannot
silently reintroduce it.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds the `nested_containers` bottle flag. On the macOS backend it starts
a rootless podman service inside the bottle and exposes its
Docker-compatible API socket, so the agent still runs `docker` and
`docker compose`. No host daemon socket is mounted and the guest gains
no capabilities; backends that cannot run a guest-local engine reject
the flag in the shared prepare template rather than ignoring it.
Podman rather than rootless Docker because Apple Container's capability
bounding set omits CAP_SYS_ADMIN, which the kernel requires to write a
multi-range uid_map via newuidmap. With no subordinate UID range podman
falls back to a single-UID self-mapping an unprivileged process may
write itself, so the image build strips /etc/subuid and /etc/subgid
entries rather than adding them.
That mapping is also why nested containers are not an isolation layer:
root inside one is the agent user outside it. They are a build/test
convenience; the bottle remains the boundary.
Ports the spike branch onto main, renaming docker_access — it implied
Docker and granted access to nothing on the host — and drops podman
from the derived layer now that every built-in image ships it (#451).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
didericis