Today there's no way to correlate a CLI failure with a daemon log
line. operationLog records relative timing but no id, two concurrent
vm.start calls log indistinguishably, and the async
vmCreateOperationState.ID is user-facing yet never reaches the
journal. The root helper logs plain text to stderr while bangerd
logs JSON, so a merged journalctl is hard to grep across the
trust-boundary split.
Mint a per-RPC op id at dispatch entry, store it on context, and
include it as an "op_id" attr on every operationLog record. The
id is stamped onto every error response (including the early
short-circuit paths bad_version and unknown_method). rpc.Call
forwards the context op id on requests so a daemon RPC and the
helper RPCs it triggers all share one id. The helper now logs
JSON to match bangerd, adopts the inbound id, and emits a single
"helper rpc completed" / "helper rpc failed" line per call so
operators can see at a glance how long each privileged op took.
vmCreateOperationState.ID is now the same id dispatch generated
for vm.create.begin — one identifier between client status polls,
daemon logs, and helper logs.
The wire format gains two optional fields: rpc.Request.OpID and
rpc.ErrorResponse.OpID, both omitempty so older peers (and the
opposite direction) ignore them. ErrorResponse.Error() now appends
"(op-XXXXXX)" to its string form when set; existing callers that
just print err.Error() get the id for free.
Tests cover: dispatch stamps op_id on unknown_method, bad_version,
and handler-returned errors; rpc.Call exposes the typed
*ErrorResponse via errors.As so the CLI can read code/op_id; ctx
op_id is forwarded to the server in the request envelope.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The dispatch method was a single ~240-line switch of 34 cases, each
following the same pattern: decode params into some type P, call a
service method returning (R, error), wrap R in a result struct and
either marshalResultOrError-encode or return a raw rpc.NewError.
Adding a method was a 4-line ceremony per site, and grepping for
"methods banger speaks" meant reading the full switch.
New shape, in internal/daemon/dispatch.go:
- handler is the uniform `func(ctx, d, req) rpc.Response` type
every method dispatches through.
- paramHandler[P, R] is the generic wrapper that absorbs 28 of
the 34 cases (decode, call, marshal). No reflection — P and R
are deduced from the service-call literal, so each map entry
is a one-liner referencing a small adapter func.
- noParamHandler[R] is the decode-free variant for 6 methods
that don't carry params.
- rpcHandlers is the single source of truth for which methods
exist and which adapter they dispatch to.
- Four specials (ping, shutdown, vm.logs, vm.ssh) stay as named
`handler`-typed functions: ping/shutdown encode with raw
rpc.NewResult, vm.logs/vm.ssh need pre-service validation to
emit distinct error codes (not_found, not_running) that the
generic wrapper maps uniformly to operation_failed.
Daemon.dispatch shrinks from a 240-line switch to 11 lines:
version check, test-only handler short-circuit, table lookup,
invoke-or-unknown.
Tests:
- TestRPCHandlersMatchDocumentedMethods — keyset guard. Adding
or removing a method without updating the expected slice is a
red flag the test surfaces.
- TestRPCHandlersAllNonNil — catches nil-function registrations.
All pre-existing dispatch tests (param decode, error codes, etc.)
keep passing unchanged — the handler contract for any given
method is byte-identical from the RPC client's perspective. Smoke
(all 21 scenarios) exercises every code path end-to-end.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
