Code RoomDocker token in layer history
HardPrep Room Coding #4123

Docker token in layer history

Vibe & agenticSecuritySenior–Staff~18 min

An AI assistant produced this Dockerfile to "build the app and pull private npm packages." The image works and the build passes. A security engineer says the token is still in the image. How?

Implement
recoverable_secret_paths(instructions: list[str]) → list[str]
Examples
in[["write|/root/.npmrc|NPM_TOKEN","rm|/root/.npmrc"]]out["/root/.npmrc"]
in[["mount|/root/.npmrc|NPM_TOKEN"]]out[]
in[["write|/root/.npmrc|NPM_TOKEN","stage|runtime","copy|/app/dist|"]]out[]
What a strong answer looks like

Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it (tests, edge cases, reading critically), and how you’d re-prompt or decompose to get it right.

0:00 of about 18 min

Vibe & agentic: describe the solution in plain language (or narrate it) and the coach grades your approach.

Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.