[LamaSu]

What

pcc-node could report a kernel as registered when the gateway had rejected the registration. This PR stops that.

Found in incident #2984, where pcc-node start ran against prod with no valid key:

• POST /api/kernels returned HTTP 401;
• start still printed Node running. Accepting jobs.;
• the daemon logged Kernel … registered;
• the node then polled, announced and heartbeated with the rejected key every few seconds for five minutes. Every request got a 401.

Root cause: register_kernel returned an error dict on failure, and no caller could tell it apart from a registration record. start ignored the value. The daemon logged success whenever no exception was raised. discover --register counted every attempt as registered.

Change

• register_kernel raises KernelRegistrationError(kernel_id, status, data) for anything other than 200 or 201. That includes status 0 (unreachable) and 202. .auth_rejected is true for 401 and 403.
• start, on failure:
  • prints Kernel X was NOT registered: <why> Nothing was started. and exits non-zero;
  • skips devices, the signing key, announce and the daemon. The existing comment already required that ("register them only after the authenticated kernel registration succeeds"), but the code did not do it;
  • saves a key the gateway minted in this run before aborting, so the key is not lost. If the save fails, it says so, and it never prints the key.
• daemon:
  • registered is logged only on success;
  • a rejected key (401/403) stops the daemon before it polls, removes the PID file, and makes start exit 1;
  • other failures are logged as NOT registered (HTTP n), and the Daemon running line says (NOT registered).
• discover --register: a refused registration counts as failed, and the command exits 1. Output: registered 0, failed 1.

Unchanged: the success path. The same statuses (200/201) count as success, and the same requests are sent in the same order.

Tests

• pcc-node on this branch: 360 passed, 2 failed. The 2 are test_cli::TestStartCommand::test_start_flow and test_discovery::…test_start_with_discover_flag, the headless-consent failures that also fail on master. ci+fix(pcc-node): run the Python suite in CI; headless start; tests keep keys in tmp (N52) #388 fixes them.
• Merged locally with ci+fix(pcc-node): run the Python suite in CI; headless start; tests keep keys in tmp (N52) #388: 367 passed, 0 failed.
• 24 new tests:
  • test_register.py: the failure contract, and "only 200/201 counts" across 9 statuses;
  • test_registration_truth.py: start aborts honestly for 401, 0 and 503; a minted key is kept; an unsavable key is reported and not printed; a daemon stop gives a non-zero exit;
  • test_discovery.py: failures are counted honestly;
  • test_daemon_loop.py: 401 and 403 stop before polling; 503 is logged as NOT registered; success is logged.
• Changed test: TestRegisterKernel.test_failure expected the old error dict. It now expects the exception; the docstring says why.
• Mutation check: I reverted each part of the fix in turn (8 mutants). Every mutant turns the new tests red.
• Every network call in the new tests is mocked, and the base URL is http://pcc.invalid.
• Merge check: git merge-tree is clean against feat(pcc-node): settle accepted prints on device-reported completion (IPP job-state, OctoPrint /api/job) #377 (and so fix(pcc-node): emit execution_failed, never execution_completed, on failed device results (OH-1, evidence sec-10) #333/fix(pcc-node): device acceptance is submitted evidence, never execution_completed #343), ci+fix(pcc-node): run the Python suite in CI; headless start; tests keep keys in tmp (N52) #388, fix(pcc-node): announce capabilities through the heartbeat, not the store-nothing stub #390, fix(pcc-node): stop tracking the local node key file and Python build artifacts #366 and fix(pcc-node): verify_signature fails closed; never default to a key file in the checkout (N35b) #374.

Not in scope

• Device registration results are still only logged. register_devices has the same return-dict shape, so it is a follow-up.
• The daemon does not retry a registration that failed for a transient reason. It says so honestly, then carries on as before.

🤖 Generated with Claude Code

https://claude.ai/code/session_01PkeiQMnVePeBGU9svhREFy