Add tools/yaegi-check, a separate Go module (llmgw-yaegi-check,
never a dependency of the plugin module) that replicates the
Traefik Plugin Catalog analyzer (piceus)'s yaegiMiddlewareCheck:
copy the repo into a temp GOPATH, interp.New + i.Use(stdlib.Symbols),
import the plugin package, eval CreateConfig(), decode the plugin's
real .traefik.yml testData into it via a hand-rolled YAML-subset
parser plus a JSON round-trip, reflect-Call New from outside the
interpreter, then exercise the returned handler with two real HTTP
requests (authenticated GET /v1/models against the testData key, and
the same route unauthenticated). Pins github.com/traefik/yaegi to
v0.16.1, confirmed as Traefik v3.5.0's own vendored version by
downloading its go.mod.
Wire cd tools/yaegi-check && GOWORK=off go run . /Users/nvm/Documents/projects/private/traefik-llmgateway
yaegi-check: OK to run the harness from repo root.
The harness caught a real Yaegi v0.16.1 limitation: calling a struct
FIELD of variadic func type (e.g. modelRegistry.log
func(string, ...any)) with two or more variadic arguments crashes
Yaegi's CFG builder ('index out of range'). The identical call shape
through a method or interface method is unaffected — bisected with a
standalone yaegi repro to confirm the exact trigger before touching
plugin code. Fixed by pre-formatting with fmt.Sprintf at
modelRegistry's three affected call sites (registry.go) so the field
is always called with exactly one variadic argument; documented the
constraint on both modelRegistry.log and limiter.logf so it is not
reintroduced. Verified the gate itself is load-bearing by temporarily
renaming CreateConfig (harness failed non-zero) and restoring it
(harness passed again).
Also fixes two golangci-lint findings in the new harness module
(govet shadow, gosec G301 directory permissions).
Review fixes for Task 12:
1. (CRITICAL) runUnified now calls g.limiter.account BEFORE handling an
adapter error, not after returning on it. All three adapters'
forwardStream deliberately return captured usage alongside a mid-stream
error, so a client that aborts right after the usage frame arrives was
getting tokens delivered but never billed - repeated aborts bypassed
every token/cost budget. A non-streaming error path always carries zero
usage by contract, so accounting it is a no-op (account skips writes
once both total tokens and cost are zero). The zero-usage-stream logf
and the zero-usage-non-stream estimate now only fire when callErr is
nil, so a genuine error no longer gets a fabricated token estimate.
New test: TestHandleChat_MidStreamDropAfterUsageChunk_AccountsPartialUsage
(hijack+close after the usage chunk; asserts the limiter's counter shows
the captured tokens). Verified this test fails against the pre-fix
ordering and the two new alias tests below fail when their guarded
delete() call is removed, before restoring and re-running clean.
2. Added TestHandleChat_OpenAI_AliasKeyStrippedFromUpstreamBody and
TestHandleEmbeddings_OpenAI_AliasKeyStrippedFromUpstreamBody: the
openai-type adapter marshals req verbatim as the upstream wire body, so
it is the one path where a leftover gatewayAliasKey entry actually
reaches a real provider. The only existing alias-leak assertion covered
anthropic, which rebuilds the body field-by-field and was never at risk.
3. Reworded the stale comment on limiter.evaluateScope (limits.go): it
described a nil-limits scope's req counters as a normal, expected case.
Ruling (e), implemented in routes_unified.go's buildLimitScopes, means
the unified route never builds a nil-limits scope in the first place -
the nil check remains a defensive no-op, not a path any current caller
exercises.
Gates: gofmt, go vet, fieldalignment, golangci-lint (incl. gosec) all
clean; go test ./... -race -count=1 passes (full suite, including all
Task 12 tests).
Reject a nested array reply instead of recursing into it. decodeReply
now takes a depth parameter; a '*' type byte is accepted only at
depth 0, so an element that is itself an array (decodeArray calls
decodeReply at depth+1) is a protocol error rather than a recursive
call. A crafted "*1\r\n*1\r\n..." stream repeated could otherwise
recurse to Go's stack limit — a fatal, unrecoverable error, not a
panic recoverPanic can catch — from only a few megabytes of wire
input. Also lower respMaxArrayLen from 1<<20 to 1024: none of this
client's commands (AUTH, SELECT, INCRBY, EXPIRE, GET) ever return an
array reply at all, so even 1024 is generous headroom, not a limit
tuned to real traffic.
Add a store-down latch to the limiter (limits.go): after any store
operation fails, record the failure time; for storeDownLatchFor (5s)
afterward, every storeIncrBy/storeGet call short-circuits straight to
the fail-open/fail-closed policy without attempting the store at all.
One request can touch several counters (its own and its group's,
request/token/cost, day/month) — each respClient call is already
bounded to ~respCallTimeout on its own, but without the latch every
one of those still paid a fresh bounded wait against a store that had
just proven unreachable. After the window, the next operation probes
the real store again: a natural half-open retry, no separate recovery
state. Guarded by the same logMu mutex lastLogAt already uses for this
kind of small timestamp state.
Clamp respClient's dial timeout to the remaining call budget:
dialTimeoutFor returns min(respDialTimeout, time.Until(deadline)),
with a respDeadlineExceededErr (implements net.Error, Timeout() true)
returned outright if the deadline has already elapsed — e.g. this
call queued behind the client's mutex for its whole budget while an
earlier call was stuck. Without this, a future increase to
respDialTimeout alone, leaving respCallTimeout untouched, could
silently let one dial attempt consume more of a call's total budget
than the call-level deadline is supposed to allow.
New tests: a nested-array reply and an array length one over the new
1024 cap, both asserted as protocol errors; a countingErrorStore stub
proving a second checkAndCount within the latch window makes zero
additional store calls, and that the store is probed again once the
window elapses. Tightened TestLimiter_FailOpenTrue_
HungRedisServer_FallsBackQuickly's bound from <6s to <3s now that the
latch collapses its two store ops into one real network attempt.
Add resp.go: a minimal stdlib-only RESP2 client (respClient) for a
single Redis-compatible server. It lazily dials one mutex-guarded
connection, applies 2s dial/read/write deadlines, sends AUTH (if a
password is set) then SELECT on every new connection, and reconnects
once on any I/O error before giving up. do and pipeline encode
commands as "*N\r\n$len\r\n..." and decode +/-/:/$/* replies.
Add redis_store.go: redisStore implements counterStore over
respClient. incrBy pipelines INCRBY and EXPIRE in one round trip and
returns INCRBY's value; get treats a missing key (RESP null bulk) as
0.
Wire the limiter's fail-open/fail-closed policy in limits.go, which
Task 5 stored but never read: a configured store's error now routes
through storeIncrBy/storeGet. failOpen=true falls back to the
in-process memoryStore transparently; failOpen=false makes
checkAndCount return a storeDown violation and makes account drop the
sample. Both paths log through an injectable, 30s-rate-limited logf.
Wire newGateway (llmgateway.go) to build a redisStore-backed limiter
when Config.Redis is set (password through resolveSecret, failOpen
defaulting to true unless RedisConfig.FailOpen says otherwise) and a
memory-only limiter otherwise, and to route pricing.go's unknown-model
warnings through the gateway's own logf.
Validate LimitsConfig at construction: a new LimitsConfig.validate
rejects a negative int64 count limit or a negative/NaN/Inf cost limit,
called from newAuthStore for every group and every user (inline and
file-sourced) so a malformed limit is a constructor error instead of
silently behaving as unlimited.
Add RequestsPerDay, TokensPerMonth, and CostPerMonthUSD enforcement
tests alongside the existing per-minute/day/cost-per-day cases, plus
an erroringStore-backed test pair proving the fail-open (fallback
counted) and fail-closed (storeDown violation) branches directly.
Folded the validation work into this single commit rather than a
second one: it interleaves with the fail-open changes across
limits.go, limits_test.go, and llmgateway_test.go closely enough that
splitting by hunk would be artificial.
lukaszraczylo