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…upport Starting in Docker 28 (the version used by our Ubuntu 24.04 image), dockerd introduced direct-access filtering for published ports as a hardening change. That path programs iptables `-t raw` rules, which in Firecracker guest VMs can fail with: iptables ... can't initialize iptables table `raw': Table does not exist because our current guest kernel configs all have `CONFIG_IP_NF_RAW` disabled. Changes: - Set `DOCKER_INSECURE_NO_IPTABLES_RAW=1` unconditionally when starting dockerd in goinit. - Keep an inline note explaining why this is safe for our VM sandboxing model. - Update docker-in-firecracker coverage to include `docker run -p ...` in `TestFirecrackerRunWithDockerOverUDS`. - Update guest API hash expectation. - Add TODOs at the top of all guest kernel config files to enable `CONFIG_NF_TABLES` and remove the env-var fallback. Repro (before/after): run the same `bb execute` command with and without `--action_env=DOCKER_INSECURE_NO_IPTABLES_RAW=1`; `docker run -p ...` fails without it and succeeds with it.
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iain-macdonald
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maggie-lou
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Docker v28 configures direct-access filtering via iptables
-t rawfor published ports. As a result, commands likedocker run -p <port>fail withbecause our current guest kernel configs all have
CONFIG_IP_NF_RAWdisabled.Repro: run the same
bb executecommand with firecracker isolation, with and without--action_env=DOCKER_INSECURE_NO_IPTABLES_RAW=1; manually startdockerd &, sleep for a bit then rundocker run -p ...Fix:
DOCKER_INSECURE_NO_IPTABLES_RAW=1unconditionally when starting dockerd in goinit. Includes an inline note explaining why this is safe for our VM sandboxing model.CONFIG_NF_TABLESand remove the env-var fallback. (I don't want to do this right now since I think it's slightly risky, so I'd rather save this for when we incrementally start migrating to our new 6.1 config)docker run -p ...on a newer docker version.Context: https://buildbuddy-corp.slack.com/archives/C0AFN0SMNG5/p1772129387671119?thread_ts=1772012498.295389&cid=C0AFN0SMNG5