Experimental/ai-sandbox
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add --publish: the one ingress control

Browse Source 
Everything else in the file gates egress, which left an everyday request unanswered: the
agent starts a dev server inside the sandbox and a human wants to look at it. This puts a
listener on the host that forwards into the container, so a browser, curl or an API
tester reaches the server the sandboxed process runs.

`--publish [ADDR:]HOST:CONTAINER`, config `publish` and AISB_PUBLISH, repeatable, with the
cost named in the flag: it is ingress, so whatever that server serves is reachable from
the address it binds. The default address is 127.0.0.1 because a bare podman -p binds
every interface (measured) -- a port committed in a repo config must not quietly be a port
on the LAN. publish_addr changes the default machine-wide; a spec with a non-loopback
address warns on every run. The grammar is smaller than podman's on purpose: one port per
entry, no ranges, no /udp, no `*` -- this list is reviewed line by line, and typing
0.0.0.0 is the whole warning. An address means three parts, so `127.0.0.1:8000` is refused
rather than guessed. No -p alias: that flag belongs to the harness (claude -p prints).

Fail closed, as elsewhere: --net none cannot forward a port and podman discards the
mapping while starting the container anyway, so "it ran" would mean "nothing is
listening"; a host port already in use is named before the container starts, not after a
build; pick_port() will not hand the gate a port this run publishes. The container is
labelled with the ports it was given, and doctor reports them.

Inside, publish_rules() accepts tcp on the published ports in the input chain and never
the output one. Measured (docs/networking.md): pasta delivers the connection over
loopback, so that rule counts 0 packets on the reference host; it is there for a host or a
bridge network that delivers on the interface, and so that `nft list table inet aisb`
answers "what can reach this container". The ports are validated again inside the
entrypoint, because a ruleset is not somewhere to splice an unvalidated string. And the
measurement that makes a configured preview look broken: a server bound to 127.0.0.1
inside answers inside and refuses the published port outside, so dev servers must bind
0.0.0.0 -- both skills say so in the change that writes the port.

Tests. Unit: the grammar and every port list that looks right and is not, config/env/flag
precedence and dedup, the canonical spec in --print-policy, the `# ingress:` header, the
flags reaching the invocation before the image, egress enforcement byte-identical with a
port open, which chain the rule lands in and that a non-numeric port never reaches nft as
code. e2e (tests/e2e/13_publish.sh): one real container with enforce=nft where the host
gets its 200 and the same run still refuses a domain outside the allowlist at 403, the
server runs as uid 1000 with no capabilities so it cannot widen its own port, and the host
listener is gone when the container exits.

LLM-Generated: true
This commit is contained in:
ducoterra
2026-10-30 22:53:57 -04:00
parent ac2f310d10
commit 144e322391
21 changed files with 993 additions and 79 deletions
Download Patch File Download Diff File Expand all files Collapse all files
README.md
+31
View File
@@ -85,6 +85,37 @@ If you bridge your pi config (below), ai-sandbox tells you when the model endpoi
your own `models.json` points at is not in the allowlist -- pi would otherwise start
and sit there unable to answer, which reads like a broken sandbox.
### Opening a port: ingress, on purpose
Everything above is egress. To look at a server the sandbox is running -- a browser on
your machine hitting the dev server the agent started -- publish a port:
```bash
ai-sandbox --publish 8000 # host 127.0.0.1:8000 -> container 8000
ai-sandbox --publish 18080:8000 # a different host port
ai-sandbox --publish 0.0.0.0:18080:8000 # every interface: warned about, on purpose
```
| | |
|---|---|
| Default address | `127.0.0.1`. A bare port never lands on your network; `publish_addr` changes the default, an address in the spec overrides it. |
| Shape | `port`, `host:container`, or `addr:host:container`. One port per entry: no ranges, no `/udp` -- this list is reviewed line by line. An address means three parts, so `127.0.0.1:8000` is refused rather than guessed, and podman's `*` shorthand is refused too: writing `0.0.0.0` makes the next reader see what is open. |
| Cost | It is **ingress**: whatever that server serves, or accepts, is reachable from that address. Egress is untouched: the same run that answers your browser still refuses a domain outside the allowlist (`tests/e2e/13_publish.sh`). |
| In the container | The ruleset accepts tcp on the published ports and says so (`nft list table inet aisb`), and the entrypoint logs the ports it opened. |
| Needs a network | `--net none` + `--publish` is a refusal, not a warning: measured, podman discards port mappings and starts the container anyway. |
| The server must bind `0.0.0.0` | Measured: pasta delivers the connection to the container's own address, so `--bind 127.0.0.1` inside answers on the inside and answers nothing on the outside. `npm run dev -- --host 0.0.0.0`, `uvicorn --host 0.0.0.0`. |
```ini
# .ai-sandbox/config -- the dev server this project runs, previewed from the host
publish = 8000 # http://127.0.0.1:8000
publish = 18080:3000 # vite, on a host port that is free
```
The reverse -- a sandboxed process reaching a database, queue or mock API you run on
your own machine -- is egress and needs no new flag: `allow = 100.64.0.1:<port>`, where
`100.64.0.1` is the address that stands for the host's loopback. See
[`docs/networking.md`](docs/networking.md).
## Environment
Nothing is inherited except `TERM LANG LC_ALL LC_CTYPE TZ`.