Config gets two new surfaces (llmgateway.go): Config.ModelMeta
(map[string]*ModelMetaConfig, keyed by exact "provider/model" or a
bare model id) for operator overrides, and ProviderConfig.MetadataPath
for openai-type providers whose discovery should also capture per-model
context (LM Studio's native /api/v0/models shape).
modelmeta.go adds the layering itself: resolveModelMeta applies config
override > discovered context > builtin table > absent for context, and
config override/free > builtin > absent for cost (discovery never
reports cost). resolveAliasModelMeta implements alias inheritance: an
alias inherits its target's fully resolved metadata unless the alias
itself has its own modelMeta entry, applied per field. validateModelMeta
rejects negative values and a free:true/non-zero-cost contradiction at
construction.
registry.go wires this into the request path: providerState gains a
discoveredContext map (stale-while-error, mirroring discovered's own
convention) with contextFor/setDiscoveredContext; a new optional
modelMetadataFetcher interface, type-asserted (interpreted-to-interpreted,
documented as yaegi-safe against the Trap-4 restriction) rather than
added to providerAdapter, lets warmFill/refreshProvider capture metadata
alongside listModels without touching anthropic/gemini adapters at all.
modelObject/listFor now attach resolved context_window/pricing to every
GET /v1/models entry, including aliases (resolveMetaFor/
resolveMetaForAlias/resolveMetaForAliasName).
provider_openai.go implements modelMetadataFetcher: fetchModelMetadata
reads ProviderConfig.MetadataPath, preferring loaded_context_length over
max_context_length when the LM Studio response reports both. providers.go
wires MetadataPath onto the adapter in buildAdapters.
tools/yaegi-check/main.go adds one cheap modelMeta config-override
assertion to the existing attempt-accounting harness, proving
resolveModelMeta's config-override layer and the context_window/pricing
extension fields both run correctly under the real Yaegi interpreter.
Review round 2 fix batch for the federated /mcp endpoint, driven by a
live probe against all 11 production MCP servers behind this gateway
through the byte-pipe proxy (session-less tools/list): 8 answer bare,
readitall and fetch reject it and need a session handshake, playwright
is a legacy HTTP+SSE-transport server (400 Missing sessionId) that no
handshake fixes.
MF1: every backend call now runs under its own context.WithTimeout
derived from r.Context() — toolsListBackendTimeout (20s) per fan-out
call, toolsCallBackendTimeout (120s) for tools/call, named constants.
MF2: doBackendJSONRPC rejects any non-2xx upstream status as an error
(previously unchecked — a non-JSON-RPC error body only failed by
accident of not parsing). parseBackendJSONRPC additionally rejects a
validly-JSON body that carries neither "result" nor "error" — the
exact silent-failure shape that would otherwise decode into an
all-zero jsonrpcResponse and hand the client a bare
{"jsonrpc":"2.0","id":1}. mcpFederatedToolsCall carries a
defensive final guard against the same shape before relaying.
MF3: mcpBackendCall is now bare-first-with-fallback — attempt the
bare call; on a JSON-RPC error OR HTTP 4xx (never a network failure,
timeout, or 5xx), retry once via initialize -> capture Mcp-Session-Id
-> retry with the header -> best-effort DELETE close. A legacy
HTTP+SSE-transport server (URL path ending "/sse") is excluded from
federation entirely before ever reaching this — isLegacySSETransportURL,
folded into allowedMCPServerNames — since no handshake fixes a
different transport; it stays reachable via the per-server proxy. When
every attempted server fails, tools/list returns a JSON-RPC internal
error ("no MCP server reachable") instead of a silently-empty list.
SF6: defaultMCPProtocolVersion -> "2025-11-25"; a caller's own
protocolVersion is echoed back only from a small explicit allowlist
(knownMCPProtocolVersions), falling back to the default otherwise —
never echoes an arbitrary caller string as this gateway's own claimed
capability.
SF8: GET/DELETE/etc. on exactly /mcp is now 405 with Allow: POST,
checked before auth (llmgateway.go).
Folded minors: countTargetRequests batches per-target counter writes
for tools/list's whole fan-out into ONE storeIncrMulti call after
wg.Wait() (was one call per server); every "actually contacted" doc
comment now says "attempted" (attribution is attempt-, not
success-, accounting); lastSSEDataLine documents its no-cross-message-
id-correlation limitation; routes_unified.go's stale buildLimitScopes/
withTotalScope comments (which claimed handleAdminAPI calls
buildLimitScopes directly — it never has) are corrected; jsonrpcRequest
documents why its "jsonrpc" field is decoded but never validated.
Tests: ~30 new/updated cases covering per-backend timeout derivation
(via the shorter-of-two-context-deadlines technique, no real 20s/120s
waits), non-2xx rejection, the empty-envelope guard end-to-end,
handshake-trigger classification (table-driven: JSON-RPC error and
HTTP 4xx trigger, HTTP 500 and network failure do not), the full
handshake sequence (bare -> initialize -> retry -> close, asserted
call-by-call), handshake-gives-up-too, all-servers-failed, legacy-SSE
exclusion (never contacted, in both tools/list and tools/call),
protocol-version allowlist (all 4 versions + one rejected), 405/Allow,
and best-effort session-close failure never surfacing to the caller.
New POST /mcp: a single JSON-RPC 2.0 endpoint aggregating every MCP
server the caller's group can reach, for clients built against the
earlier pre-plugin gateway's one aggregated endpoint (pugbot's
mcpclient, agentkit) rather than this plugin's per-server
/mcp/{name}/... proxy.
Unlike the per-server proxy, this cannot be a byte-level reverse
proxy: aggregating N servers' tools/list results, or routing one
tools/call to the single right server, both require actually parsing
the JSON-RPC envelope. The gateway answers initialize/ping locally
and, for tools/list/tools/call, issues its own outbound JSON-RPC
call(s) to the relevant backend server(s) per incoming request — no
session state persisted across separate client requests, matching the
per-server proxy's own complete absence of gateway-side session
tracking. A backend may answer bare JSON or an SSE stream; both are
accepted (parseBackendJSONRPC).
- tools/list fans out concurrently to every allowed server and merges
results, prefixing each tool "<serverName>_<toolName>" — the
underscore convention the earlier agentgateway used and that
pugbot/agentkit already persist in their own tool-id records (e.g.
brave-search_brave_web_search, verified live). A failing/unreachable
server is skipped, not a whole-call failure.
- tools/call resolves the target by LONGEST matching
"<serverName>_" prefix against the caller's allowed servers
(disambiguates a server name that prefixes another), strips it,
forwards, and relays the result/error under the CLIENT's own id. An
unresolvable prefix (unconfigured, or authz-excluded) is a JSON-RPC
invalid-params error, not a 404.
- Reuses Feature B's countTargetRequest for per-target attribution —
every backend server actually contacted increments its own scope.
- notifications/* -> 202 no body; unknown method -> JSON-RPC
method-not-found; malformed body -> JSON-RPC parse error with
id:null (spec-required, not omitted).
No new limits config surface. Tests cover prefix resolution
(table-driven, incl. the ambiguous-prefix case), SSE/JSON backend
parsing, group-restricted aggregation (a denied server is never even
contacted), call routing/prefix-stripping, backend error relay,
unreachable-server handling, unknown-prefix errors, and per-target
counter attribution. README's MCP and A2A section documents the
federation contract and naming convention; the architecture diagram
and the total-scope/rejected-before-quota notes are updated to
include the new route.
GroupConfig gains CacheTTL (json cacheTTL, empty inherits the global
cache.ttl). Parsed and validated at construction (newAuthStore,
groupCacheTTL in cache.go): a malformed duration, a duration <= 0, or
CacheTTL set while the global cache block is not configured is a
constructor error naming the group, mirroring Cache:true's existing
"nothing to inherit from" check.
group carries the resolved time.Duration (0 means inherit).
responseCache.store gains an explicit ttl parameter; routes_unified.go
computes effectiveTTL(g.cache, grp) immediately before each store call,
so setEx's Redis-native EX seconds reflect the group's own override.
Tests: constructor-error table, empty-inherits and valid-override
resolution, effectiveTTL inheritance/override, a scripted-RESP-server
proof that store's SET...EX carries a different value per group, and an
end-to-end Gateway.ServeHTTP test with two groups asserting the actual
wire EX value (30 vs 60) differs per group.
README: GroupConfig.cacheTTL config row and a Caching-section paragraph.
Spec §5 (v0.2): Config.ModelAliases map[string]string, alias-first
resolution precedence ahead of provider-prefix splitting, alias-OR-target
authorization, lazy target resolution with a 404 naming both ids,
/v1/models listing, admin overview alias table (JSON + dashboard), and
construction-time validation (shape, prefix-shadow, explicit-model
collision, chain, empty target).
routes_unified.go/routes_media.go needed no resolution-call-site changes
- both already pass the client's raw requested id through to
registry.resolve, so aliases inherit the __alias echo and multipart
rewrite machinery for free. cache.go needed no changes either - cacheKey
already hashes requestedModel, so two aliases resolving to the same
target already produce distinct cache entries.
Adds registry_test.go validation table + precedence/authz/lazy-404/
listing coverage, a dedicated cache-key split test, chat/embeddings/
images/audio-transcriptions end-to-end tests, an extended admin overview
test, and an integration test covering the openai-type vs anthropic-type
echo asymmetry under real Traefik+Yaegi.
Adds GET /admin (single-page dashboard), GET /admin/api/overview, and
GET /admin/api/usage per spec §4: providers/redis/cache/groups summary
and per-user/group current-window usage+limits. Gated by Config.Admin
(default off, not registered when disabled) and UserConfig.Admin.
Gate order: disabled -> 404 fall-through; unauthenticated -> 401;
authenticated non-admin -> 403; admin -> serve, counted against the
admin's own request limits like any other route.
Adds small, read-only, mutex-guarded hooks: modelRegistry.snapshot(),
limiter.currentUsage()/redisStatus(), authStore.snapshot(). No secret
field (API key, digest, redis password) is ever read into any admin
response type; verified by a canary-literal redaction test.
HTML/CSS/JS ship as a single Go raw-string const (Yaegi forbids
go:embed); confirmed interpretable via make yaegi-check.
Critical: attempts now counts retries performed AFTER the first try
(default 1 -> two tries total), not the total try count. The prior
reading made retry:{enabled:true}'s own documented default perform zero
retries. (*retryPolicy).totalTries() is the single conversion point,
clamping any attempts<1 to 1 so do()'s loop bound can never compute <=0
and skip calling call() entirely (no (nil,nil) return path).
Backoff waits are now ctx-aware: sleepFn func(time.Duration) is replaced
by waitFn func(context.Context, time.Duration) bool, whose production
implementation (defaultWaitFn) selects between time.After(d) and
ctx.Done(). A context canceled mid-wait aborts the remaining retries
immediately instead of blocking out the full backoff.
Also: classify a request-build failure (invalid method/URL) as
non-transient via errRequestBuildFailed, since retrying an identically
malformed request only wastes attempts; drop the drain cap to a
dedicated 64KiB constant instead of the 32MiB response cap; fix a
t.Fatal call from a non-test goroutine in the mid-stream-death test;
drop the misleading omitempty on Config.Retry (a struct value is never
'empty' to encoding/json); document the Retry-After >2s-falls-back-to-
backoff behavior and cover it with a direct table test.
README: add the retry config table, a RetryConfig field reference, and
a Retry section documenting the semantics. examples/kubernetes.yaml
gains a retry block alongside its other optional sections.
Gate: go test -race, gofmt, vet, yaegi-check, golangci-lint (incl a
fieldalignment fix on two new test structs) all clean. 295 subtests
pass, 0 failed. integration/ untouched.
Adds spec §1's opt-in retry engine: RetryConfig (top-level, zero value
disabled) and retryPolicy (retry.go), wired into upstreamJSON — the
single HTTP chokepoint every adapter's chat/embeddings/listModels call
already funneled through. A transient failure (net error, 429, 5xx)
retries up to Attempts times with exponential backoff capped at 2s,
honoring a qualifying Retry-After header on 429, draining and closing
each failed attempt's body before retrying. Never retries a non-429 4xx,
a translate error, or after context cancellation.
Because upstreamJSON returns before any adapter forwards a byte to the
client (forwardStream/forwardJSON run only after it returns), the
'zero bytes reached client' safety rule and the 'streaming retries only
the initial exchange' rule both hold by construction — no adapter
streaming logic needed to change.
buildAdapters(cfg) keeps its v0.1 signature: it derives the retryPolicy
from cfg.Retry internally rather than taking it as a parameter, so
every existing direct call (15+ across provider_openai_test.go) keeps
compiling unmodified. Every v0.1 test passes byte-identically, without
edits.
C1 (quota bypass): a client sending stream_options.include_usage=false
suppressed upstream usage reporting and escaped every token/cost budget,
since the non-streaming T12 estimate never covers a streaming response.
chatCompletion (provider_openai.go) now always forces include_usage=true
on the outgoing request, merged into a copy of the client's own
stream_options map so the caller's map is never mutated in place.
clientAskedUsage is derived from the client's own value via isTruthy, so
the usage-only chunk is still suppressed for a client that never asked
for it.
I1 (vacuous security tests): the X-Api-Key credential-strip set had zero
effective coverage — existing tests either never sent x-api-key, or
targeted anthropic, whose injectAuth overwrites x-api-key regardless of
whether the strip ran. Added one openai-passthrough and one MCP-proxy
test that authenticate via x-api-key itself and assert it arrives empty
upstream. Mutation-checked: both fail when "X-Api-Key": true is removed
from gatewayCredentialHeaders (verified, then restored).
I3 (auth-event logging): added Gateway.logAuthEvent (logger.go), called
at all six authStore.identify call sites (llmgateway.go's ServeHTTP,
routes_unified.go's handleModels). A failed attempt logs method, path,
and remote address; a success logs the resolved user's name and route.
Neither line ever includes the presented API key.
M2 (usage.estimated): runUnified now reads result.estimated and logs the
estimate explicitly when a non-streaming response's usage falls back to
the body-size heuristic, making the field genuinely read — removes the
stale //nolint:unused on limits.go's usage struct.
M8 (gosec consistency): secrets.go's file: secret path read now carries
the same "#nosec G304 -- operator-supplied file path from middleware
config" annotation as users_file.go's equivalent read.
Doc nit: mcp_a2a.go's validateTargetURLs comment now also names the
dot-only ("."/"..") rule validateConfigName enforces, not just character
set and reserved names.
Gates: go test ./... -count=1 (-race) green, gofmt -l . empty, go vet
clean, make yaegi-check OK, golangci-lint (gosec+staticcheck+unused+
errcheck+govet, global config) 0 issues.
Add GET /v1/mcp/servers and GET /v1/agents: group-filtered,
name-sorted registry listings of configured MCP servers and A2A
agents, with their gateway-relative proxy (and, for agents, card)
URLs.
Add handleTargetProxy for /mcp/{name}/{rest...} and
/a2a/{name}/{rest...}: reverse-proxies to the target's configured
URL. Checks run unknown name (404), group deny via allowsMCP/
allowsAgent (403), request-rate limits (429/503), then Upgrade
(501) and path traversal (400) around the proxy call itself. No
upstream credential is injected — MCP servers and A2A agents are
in-cluster targets, unlike native provider passthrough.
Extract proxyUpstream from routes_passthrough.go's handlePassthrough
into a shared reverse-proxy core (header stripping, SSE-safe
flushWriter streaming, dead-upstream 502, canceled-client log-only,
optional JSON usage teeing) used by both native passthrough and the
new target proxy. Behavior-preserving for Task 13: its tests pass
unmodified.
Validate every configured MCP-server and agent target URL at
construction (url.Parse, http/https scheme only) — a malformed or
non-HTTP target is a constructor error, not a per-request 502.
Implements Task 12: POST /v1/chat/completions and POST /v1/embeddings
through a shared pipeline (routes_unified.go: handleChat, handleEmbeddings,
runUnified) wired into ServeHTTP's dispatch in llmgateway.go.
Pipeline: decode (10MiB cap) -> resolve model -> enforce user/group
limits -> call adapter -> account usage, translating every failure mode
into its HTTP envelope per the task brief's carried rulings:
- ALIAS ECHO (ruling a): the client-requested model id is threaded to the
adapter via the internal gatewayAliasKey convention and echoed back in
anthropic/gemini's translated response model field; every adapter
strips the key before building its upstream wire body so it never
leaks to a real provider.
- Limit violations (ruling b): storeDown -> 503 server_error; otherwise
429 rate_limit_error with Retry-After when the violation names a
window.
- Stream-safe error handling (ruling c): statusTrackingWriter.wroteHeader
gates whether an adapter error still gets an envelope; providerHTTPError
wraps into {error:{message,type,code,upstream}}; translateError maps to
400/501; context.Canceled logs quietly; anything else is a 502.
- Usage/accounting (ruling d): zero non-streaming usage gets a
ceil(len(body)/4) prompt-token estimate; zero streaming usage logs once
and accounts the request only. unifiedCostMicros extends costMicros'
single-id lookup to canonical-then-bare without changing its signature.
- Scopes (ruling e): user scope only when u.limits is set, group scope
only when grp.limits is set, user first.
routes_unified_test.go drives every case end-to-end through
Gateway.ServeHTTP against httptest fake upstreams (openai- and
anthropic-shaped): happy path with counters asserted via the limiter's
own store, incremental stream flushing, 401/403/404/429/503, embeddings,
alias echo through a provider-prefixed anthropic request, wrapped
upstream error envelopes, and a mid-stream drop that must not append a
second envelope to an already-committed response.
Gates: gofmt, go vet, fieldalignment, golangci-lint (incl. gosec) all
clean; go test ./... -race -count=1 passes.
1. refreshProvider (the plugin's only background goroutine) had no
recover(): a panicking adapter's listModels would crash the whole
Traefik process. Restructured around deferred recover + finishRefresh,
so a panic is turned into a logged error, inFlight always releases, and
the next interval retries. Documented as a scoped exception to
limits.go's no-background-goroutine rule.
2. newGateway wrapped ctx in an outer 5s WithTimeout before warmFill,
but warmFill already derives a fresh 5s budget per provider from
whatever ctx it receives. The outer wrap made that a single budget
shared across every discovery-enabled provider instead of a per-provider
one - providers after the first could get a near-expired context and
fail instantly. Dropped the outer wrapper; construction's worst case is
now N * 5s, accepted.
3. group.allowsModel stripped at any first slash, so a glob like
'deepseek-*' could spuriously match a bare model id that merely
contains a slash (e.g. an upstream's own 'uni/deepseek-v4-flash-0731'
naming) even though the leading segment names no configured provider.
allowsModel is now an exact glob with no internal splitting;
resolveAgainst and listFor generate the provider-prefixed and
bare-suffix candidates themselves, only when a prefix legitimately
names a configured provider. Updated the Task-3 TestIdentify assertion
to match.
4. Annotated the discarded json.Encode error in handleModels.
Gate: go test ./... -count=1, -race, gofmt, vet, fieldalignment,
golangci-lint (incl gosec) all clean.
Adds modelRegistry: per-provider explicit+discovered model sets, bare-id
and provider-prefixed resolution with sorted-name collision precedence,
group authorization pairing (allowsModel AND allowsProvider), and a
group-filtered OpenAI-compatible /v1/models catalog.
Discovery is lazy and throttled per provider: newGateway runs a
synchronous 5s-bounded warm fill for discovery-enabled providers
(non-fatal on error), and Gateway.ServeHTTP triggers a throttled,
inFlight-guarded background refresh per provider per interval
(default 1h, per-provider DiscoveryInterval parsed at construction).
A failed refresh keeps the previous discovered set (stale-while-error).
Wires GET /v1/models into ServeHTTP (auth required, 401 envelope
otherwise) and gives Gateway its adapters/registry fields, both built
in newGateway.
newModelRegistry's signature gained an error return beyond the task
brief's literal listing: an invalid DiscoveryInterval must be a
constructor error per the controller ruling, which the brief's bare
*modelRegistry signature could not express.
Bound respClient's worst-case latency to one respCallTimeout per
do/pipeline call instead of per read/write/handshake step. Compute a
single absolute deadline at call entry, apply it once via
conn.SetDeadline after connecting (covering the AUTH/SELECT handshake
and the call's own command I/O), and skip the reconnect-retry when the
failing attempt was a timeout (errors.As -> net.Error, Timeout()) — a
peer that accepted the connection and went silent must not be asked
the same non-question twice. Previously each read, write, and dial got
its own fresh 2s budget and every caller queued behind the client's
single mutex, so a hung (not merely refused) Redis-compatible server
could stall one checkAndCount call for 16-32s+.
Cap decodeBulk/decodeArray's wire-declared lengths (respMaxBulkLen
64MiB, respMaxArrayLen 1<<20) before allocating: an unguarded
"$9223372036854775807\r\n" overflows n+2 into a negative slice length
and panics make([]byte, n+2); a merely huge-but-valid length forces an
outsized allocation either way. decodeBulk also now verifies its two
trailing bytes are CRLF. Bound readLine to respMaxLineLen (64KiB),
reading byte-by-byte so it can bail before ever buffering an unbounded
line from a peer that never sends '\n'.
Fix TestLimiter_FailClosed_BudgetReadReturnsStoreDownViolation: the
erroringStore it used fails incrBy too, so checkAndCount's own
increment loop already returned a storeDown violation before
evaluateScope (and therefore budgetViolation) ever ran, leaving
budgetViolation's storeDown branch uncovered. Replace it with a stub
that only fails get, so the test's TokensPerDay limit actually drives
evaluateScope into budgetViolation's fail-closed path.
Document redis_store.go's incrBy as deliberately at-least-once: the
reconnect-retry can re-send INCRBY after a lost reply (possible
over-count), and fail-open can additionally count in the fallback —
both fail-safe (more restrictive), never fail-open in the unsafe
direction.
Validate Redis.DB >= 0 in newConfiguredLimiter alongside Address, so a
negative db is a constructor error rather than a SELECT -1 on the wire.
New tests: a hung (accepts, never replies) fake RESP server proving a
respClient call and a failOpen limiter call both stay bounded rather
than stacking timeouts; decodeReply subtests for an oversized bulk
length, a length just over the cap, a huge array length, a bad bulk
trailer, and an oversized line; a negative-DB constructor-rejection
test.
Add resp.go: a minimal stdlib-only RESP2 client (respClient) for a
single Redis-compatible server. It lazily dials one mutex-guarded
connection, applies 2s dial/read/write deadlines, sends AUTH (if a
password is set) then SELECT on every new connection, and reconnects
once on any I/O error before giving up. do and pipeline encode
commands as "*N\r\n$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.
- users_file.go: maybeReload uses reloadMu.TryLock() instead of Lock().
A full reload (stat+read+parse+replaceFileUsers, incl. per-user
resolveSecret file reads) could otherwise block every concurrent
ServeHTTP request for its whole duration, negating the buildMu/mu
lock split. A request that finds a reload in flight now skips this
cycle; reload stays throttled and best-effort.
- users_file.go: mtime check changed from ModTime().After(lastModTime)
to ModTime().Equal(lastModTime), so a backward mtime move (restore
from backup, cp -p) still triggers a reload instead of being
skipped. Added a regression test with os.Chtimes into the past.
- llmgateway.go: attachUsersFile now stats the file before loading it,
matching maybeReload's ordering, so a write landing between stat and
load is caught on the next check instead of being lost. Documented
why the ignored statErr is safe (falls back to zero lastModTime,
causing one harmless extra reload).
Add usersFile (newUsersFile/load) for the JSON users-file shape
{"users":[{name,group,apiKey,limits?}]}, and authStore.maybeReload
for throttled hot reload: checks mtime at most every reloadEvery
(5s), reloads on change, keeps the last good set and logs via
errorf on any error (stat, parse, or a rejected replace), and logs
via logf when the reload changes the file-sourced user count.
nowFn is injectable for tests.
Wire-up in llmgateway.go: newGateway does a synchronous initial
load when Users.File is set (a bad initial file fails the
constructor); ServeHTTP calls g.auth.maybeReload() at entry
(no-op when no file is configured).
Also fixes replaceFileUsers's merge semantics: a file user now
overrides an inline user of the same name, even when their keys
differ, dropping the inline entry from the rebuilt set. The prior
digest-only keying let a same-named inline/file pair with
different keys coexist instead of the file version winning.
lukaszraczylo