[8.5](backport #1904) Unique limiters for each API listener

CHANGELOG.next.asciidoc

@@ -12,6 +12,7 @@
 - Add error detail to catch-all HTTP error response. {pull}1854[1854]
 - Fix issue were errors where being ignored written to elasticsearch. {pull}1896[1896]
 - LoadServerLimits will not overwrite specified limits when loading default/agent number specified values. {issue}1841[1841] {pull}1912[1912]
+- Use seperate rate limiters for internal and external API listeners. {issue}1859[1859] {pull}1904[1904]
 
 ==== New Features
 

cmd/fleet/main.go

@@ -907,10 +907,10 @@ func (f *FleetServer) runSubsystems(ctx context.Context, cfg *config.Config, g *
 	ack := api.NewAckT(&cfg.Inputs[0].Server, bulker, f.cache)
 	st := api.NewStatusT(&cfg.Inputs[0].Server, bulker, f.cache)
 
-	router := api.NewRouter(ctx, bulker, ct, et, at, ack, st, sm, tracer, f.bi)
+	router := api.NewRouter(&cfg.Inputs[0].Server, bulker, ct, et, at, ack, st, sm, tracer, f.bi)
 
 	g.Go(loggedRunFunc(ctx, "Http server", func(ctx context.Context) error {
-		return api.Run(ctx, router, &cfg.Inputs[0].Server)
+		return router.Run(ctx)
 	}))
 
 	return err

internal/pkg/api/error.go

@@ -12,7 +12,6 @@ import (
 	"strings"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/dl"
-	"github.com/elastic/fleet-server/v7/internal/pkg/limit"
 	"github.com/elastic/fleet-server/v7/internal/pkg/logger"
 
 	"github.com/pkg/errors"
@@ -43,7 +42,6 @@ type HTTPErrResp struct {
 
 // NewHTTPErrResp creates an ErrResp from a go error
 func NewHTTPErrResp(err error) HTTPErrResp {
-
 	errTable := []struct {
 		target error
 		meta   HTTPErrResp
@@ -57,24 +55,6 @@ func NewHTTPErrResp(err error) HTTPErrResp {
 				zerolog.WarnLevel,
 			},
 		},
-		{
-			limit.ErrRateLimit,
-			HTTPErrResp{
-				http.StatusTooManyRequests,
-				"RateLimit",
-				"exceeded the rate limit",
-				zerolog.DebugLevel,
-			},
-		},
-		{
-			limit.ErrMaxLimit,
-			HTTPErrResp{
-				http.StatusTooManyRequests,
-				"MaxLimit",
-				"exceeded the max limit",
-				zerolog.DebugLevel,
-			},
-		},
 		{
 			ErrAPIKeyNotEnabled,
 			HTTPErrResp{

internal/pkg/api/handleAck.go

@@ -25,7 +25,6 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/config"
 	"github.com/elastic/fleet-server/v7/internal/pkg/dl"
 	"github.com/elastic/fleet-server/v7/internal/pkg/es"
-	"github.com/elastic/fleet-server/v7/internal/pkg/limit"
 	"github.com/elastic/fleet-server/v7/internal/pkg/logger"
 	"github.com/elastic/fleet-server/v7/internal/pkg/model"
 	"github.com/elastic/fleet-server/v7/internal/pkg/policy"
@@ -42,27 +41,21 @@ func (e *HTTPError) Error() string {
 
 type AckT struct {
 	cfg   *config.Server
-	limit *limit.Limiter
 	bulk  bulk.Bulk
 	cache cache.Cache
 }
 
 func NewAckT(cfg *config.Server, bulker bulk.Bulk, cache cache.Cache) *AckT {
-	log.Info().
-		Interface("limits", cfg.Limits.AckLimit).
-		Msg("Setting config ack_limits")
-
 	return &AckT{
 		cfg:   cfg,
 		bulk:  bulker,
 		cache: cache,
-		limit: limit.NewLimiter(&cfg.Limits.AckLimit),
 	}
 }
 
-func (rt Router) handleAcks(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
+//nolint:dupl // function body calls different internal handler then handleCheckin
+func (rt *Router) handleAcks(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
 	start := time.Now()
-
 	id := ps.ByName("id")
 
 	reqID := r.Header.Get(logger.HeaderRequestID)
@@ -91,12 +84,6 @@ func (rt Router) handleAcks(w http.ResponseWriter, r *http.Request, ps httproute
 }
 
 func (ack *AckT) handleAcks(zlog *zerolog.Logger, w http.ResponseWriter, r *http.Request, id string) error {
-	limitF, err := ack.limit.Acquire()
-	if err != nil {
-		return err
-	}
-	defer limitF()
-
 	agent, err := authAgent(r, &id, ack.bulk, ack.cache)
 	if err != nil {
 		return err
@@ -107,10 +94,6 @@ func (ack *AckT) handleAcks(zlog *zerolog.Logger, w http.ResponseWriter, r *http
 		return ctx.Str(LogAccessAPIKeyID, agent.AccessAPIKeyID)
 	})
 
-	// Metrics; serenity now.
-	dfunc := cntAcks.IncStart()
-	defer dfunc()
-
 	return ack.processRequest(*zlog, w, r, agent)
 }
 

internal/pkg/api/handleArtifacts.go

@@ -19,7 +19,6 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/cache"
 	"github.com/elastic/fleet-server/v7/internal/pkg/config"
 	"github.com/elastic/fleet-server/v7/internal/pkg/dl"
-	"github.com/elastic/fleet-server/v7/internal/pkg/limit"
 	"github.com/elastic/fleet-server/v7/internal/pkg/logger"
 	"github.com/elastic/fleet-server/v7/internal/pkg/model"
 	"github.com/elastic/fleet-server/v7/internal/pkg/throttle"
@@ -46,24 +45,17 @@ type ArtifactT struct {
 	bulker     bulk.Bulk
 	cache      cache.Cache
 	esThrottle *throttle.Throttle
-	limit      *limit.Limiter
 }
 
 func NewArtifactT(cfg *config.Server, bulker bulk.Bulk, cache cache.Cache) *ArtifactT {
-	log.Info().
-		Interface("limits", cfg.Limits.ArtifactLimit).
-		Int("maxParallel", defaultMaxParallel).
-		Msg("Artifact install limits")
-
 	return &ArtifactT{
 		bulker:     bulker,
 		cache:      cache,
-		limit:      limit.NewLimiter(&cfg.Limits.ArtifactLimit),
 		esThrottle: throttle.NewThrottle(defaultMaxParallel),
 	}
 }
 
-func (rt Router) handleArtifacts(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
+func (rt *Router) handleArtifacts(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
 	start := time.Now()
 
 	var (
@@ -112,12 +104,6 @@ func (rt Router) handleArtifacts(w http.ResponseWriter, r *http.Request, ps http
 }
 
 func (at ArtifactT) handleArtifacts(zlog *zerolog.Logger, r *http.Request, id, sha2 string) (io.Reader, error) {
-	limitF, err := at.limit.Acquire()
-	if err != nil {
-		return nil, err
-	}
-	defer limitF()
-
 	// Authenticate the APIKey; retrieve agent record.
 	// Note: This is going to be a bit slow even if we hit the cache on the api key.
 	// In order to validate that the agent still has that api key, we fetch the agent record from elastic.
@@ -131,10 +117,6 @@ func (at ArtifactT) handleArtifacts(zlog *zerolog.Logger, r *http.Request, id, s
 		return ctx.Str(LogAccessAPIKeyID, agent.AccessAPIKeyID)
 	})
 
-	// Metrics; serenity now.
-	dfunc := cntArtifacts.IncStart()
-	defer dfunc()
-
 	return at.processRequest(r.Context(), *zlog, agent, id, sha2)
 }
 

internal/pkg/api/handleCheckin.go

@@ -22,7 +22,6 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/checkin"
 	"github.com/elastic/fleet-server/v7/internal/pkg/config"
 	"github.com/elastic/fleet-server/v7/internal/pkg/dl"
-	"github.com/elastic/fleet-server/v7/internal/pkg/limit"
 	"github.com/elastic/fleet-server/v7/internal/pkg/logger"
 	"github.com/elastic/fleet-server/v7/internal/pkg/model"
 	"github.com/elastic/fleet-server/v7/internal/pkg/monitor"
@@ -48,7 +47,8 @@ const (
 	kEncodingGzip = "gzip"
 )
 
-func (rt Router) handleCheckin(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
+//nolint:dupl // function body calls different internal hander then handleAck
+func (rt *Router) handleCheckin(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
 	start := time.Now()
 
 	id := ps.ByName("id")
@@ -65,12 +65,6 @@ func (rt Router) handleCheckin(w http.ResponseWriter, r *http.Request, ps httpro
 		cntCheckin.IncError(err)
 		resp := NewHTTPErrResp(err)
 
-		// Log this as warn for visibility that limit has been reached.
-		// This allows customers to tune the configuration on detection of threshold.
-		if errors.Is(err, limit.ErrMaxLimit) {
-			resp.Level = zerolog.WarnLevel
-		}
-
 		zlog.WithLevel(resp.Level).
 			Err(err).
 			Int(ECSHTTPResponseCode, resp.StatusCode).
@@ -93,7 +87,6 @@ type CheckinT struct {
 	ad     *action.Dispatcher
 	tr     *action.TokenResolver
 	bulker bulk.Bulk
-	limit  *limit.Limiter
 }
 
 func NewCheckinT(
@@ -107,14 +100,6 @@ func NewCheckinT(
 	tr *action.TokenResolver,
 	bulker bulk.Bulk,
 ) *CheckinT {
-
-	log.Info().
-		Interface("limits", cfg.Limits.CheckinLimit).
-		Dur("long_poll_timeout", cfg.Timeouts.CheckinLongPoll).
-		Dur("long_poll_timestamp", cfg.Timeouts.CheckinTimestamp).
-		Dur("long_poll_jitter", cfg.Timeouts.CheckinJitter).
-		Msg("Checkin install limits")
-
 	ct := &CheckinT{
 		verCon: verCon,
 		cfg:    cfg,
@@ -124,23 +109,15 @@ func NewCheckinT(
 		gcp:    gcp,
 		ad:     ad,
 		tr:     tr,
-		limit:  limit.NewLimiter(&cfg.Limits.CheckinLimit),
 		bulker: bulker,
 	}
 
 	return ct
 }
 
 func (ct *CheckinT) handleCheckin(zlog *zerolog.Logger, w http.ResponseWriter, r *http.Request, id string) error {
-
 	start := time.Now()
 
-	limitF, err := ct.limit.Acquire()
-	if err != nil {
-		return err
-	}
-	defer limitF()
-
 	agent, err := authAgent(r, &id, ct.bulker, ct.cache)
 	if err != nil {
 		return err
@@ -158,11 +135,6 @@ func (ct *CheckinT) handleCheckin(zlog *zerolog.Logger, w http.ResponseWriter, r
 
 	// Safely check if the agent version is different, return empty string otherwise
 	newVer := agent.CheckDifferentVersion(ver)
-
-	// Metrics; serenity now.
-	dfunc := cntCheckin.IncStart()
-	defer dfunc()
-
 	return ct.processRequest(*zlog, w, r, start, agent, newVer)
 }
 

internal/pkg/api/handleEnroll.go

@@ -16,7 +16,6 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/cache"
 	"github.com/elastic/fleet-server/v7/internal/pkg/config"
 	"github.com/elastic/fleet-server/v7/internal/pkg/dl"
-	"github.com/elastic/fleet-server/v7/internal/pkg/limit"
 	"github.com/elastic/fleet-server/v7/internal/pkg/logger"
 	"github.com/elastic/fleet-server/v7/internal/pkg/model"
 	"github.com/elastic/fleet-server/v7/internal/pkg/rollback"
@@ -49,25 +48,19 @@ type EnrollerT struct {
 	cfg    *config.Server
 	bulker bulk.Bulk
 	cache  cache.Cache
-	limit  *limit.Limiter
 }
 
 func NewEnrollerT(verCon version.Constraints, cfg *config.Server, bulker bulk.Bulk, c cache.Cache) (*EnrollerT, error) {
-	log.Info().
-		Interface("limits", cfg.Limits.EnrollLimit).
-		Msg("Setting config enroll_limit")
-
 	return &EnrollerT{
 		verCon: verCon,
 		cfg:    cfg,
-		limit:  limit.NewLimiter(&cfg.Limits.EnrollLimit),
 		bulker: bulker,
 		cache:  c,
 	}, nil
 
 }
 
-func (rt Router) handleEnroll(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
+func (rt *Router) handleEnroll(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
 	start := time.Now()
 
 	// Work around wonky router rule
@@ -129,13 +122,6 @@ func (rt Router) handleEnroll(w http.ResponseWriter, r *http.Request, ps httprou
 }
 
 func (et *EnrollerT) handleEnroll(rb *rollback.Rollback, zlog *zerolog.Logger, w http.ResponseWriter, r *http.Request) (*EnrollResponse, error) {
-
-	limitF, err := et.limit.Acquire()
-	if err != nil {
-		return nil, err
-	}
-	defer limitF()
-
 	key, err := authAPIKey(r, et.bulker, et.cache)
 	if err != nil {
 		return nil, err
@@ -151,10 +137,6 @@ func (et *EnrollerT) handleEnroll(rb *rollback.Rollback, zlog *zerolog.Logger, w
 		return nil, err
 	}
 
-	// Metrics; serenity now.
-	dfunc := cntEnroll.IncStart()
-	defer dfunc()
-
 	return et.processRequest(rb, *zlog, w, r, key.ID, ver)
 }