feat: reusable rule engine to prevent memory reallocation

internal/bench/proxy_test.go

@@ -3,7 +3,6 @@ package proxy_test
 import (
 	"context"
 	"io"
-	"log"
 	"net/http"
 	"net/http/httptest"
 	"net/http/httputil"
@@ -24,6 +23,7 @@ import (
 	redisStore "forge.cadoles.com/cadoles/bouncer/internal/store/redis"
 	"github.com/pkg/errors"
 	"github.com/redis/go-redis/v9"
+	"gitlab.com/wpetit/goweb/logger"
 	"gopkg.in/yaml.v3"
 
 	"forge.cadoles.com/cadoles/bouncer/internal/setup"
@@ -39,6 +39,19 @@ func BenchmarkProxies(b *testing.B) {
 		name := strings.TrimSuffix(filepath.Base(f), filepath.Ext(f))
 
 		b.Run(name, func(b *testing.B) {
+			heap, err := os.Create(filepath.Join("testdata", "proxies", name+"_heap.prof"))
+			if err != nil {
+				b.Fatalf("%+v", errors.Wrapf(err, "could not create heap profile"))
+			}
+
+			defer func() {
+				defer heap.Close()
+
+				if err := pprof.WriteHeapProfile(heap); err != nil {
+					b.Fatalf("%+v", errors.WithStack(err))
+				}
+			}()
+
 			conf, err := loadProxyBenchConfig(f)
 			if err != nil {
 				b.Fatalf("%+v", errors.Wrapf(err, "could notre load bench config"))
@@ -78,7 +91,7 @@ func BenchmarkProxies(b *testing.B) {
 
 			b.Logf("fetching url '%s'", rawProxyURL)
 
-			profile, err := os.Create(filepath.Join("testdata", "proxies", name+".prof"))
+			profile, err := os.Create(filepath.Join("testdata", "proxies", name+"_cpu.prof"))
 			if err != nil {
 				b.Fatalf("%+v", errors.Wrapf(err, "could not create cpu profile"))
 			}
@@ -86,7 +99,7 @@ func BenchmarkProxies(b *testing.B) {
 			defer profile.Close()
 
 			if err := pprof.StartCPUProfile(profile); err != nil {
-				log.Fatal(err)
+				b.Fatalf("%+v", errors.WithStack(err))
 			}
 
 			defer pprof.StopCPUProfile()
@@ -227,7 +240,12 @@ func createProxy(name string, conf *proxyBenchConfig, logf func(format string, a
 
 	}
 
-	layers, err := setup.GetLayers(context.Background(), config.NewDefault())
+	appConf := config.NewDefault()
+	appConf.Logger.Level = config.InterpolatedInt(logger.LevelError)
+	appConf.Layers.Authn.TemplateDir = "../../layers/authn/templates"
+	appConf.Layers.Queue.TemplateDir = "../../layers/queue/templates"
+
+	layers, err := setup.GetLayers(context.Background(), appConf)
 	if err != nil {
 		return nil, nil, errors.WithStack(err)
 	}

internal/bench/testdata/proxies/basic-auth.yml

@@ -12,7 +12,7 @@ proxy:
             attributes:
               email: foo@bar.com
         rules:
-          - set_header("Remote-User-Attr-Email", user.attrs.email)
+          - set_header(ctx, "Remote-User-Attr-Email", vars.user.attrs.email)
 fetch:
   url:
     user:

internal/bench/testdata/proxies/queue.yml

@@ -0,0 +1,10 @@
+proxy:
+  from: ["*"]
+  to: ""
+  layers:
+    queue:
+      type: queue
+      enabled: true
+      options:
+        capacity: 100
+        keepAlive: 10s

internal/bench/testdata/proxies/rewriter.yml

@@ -8,5 +8,5 @@ proxy:
       options:
         rules:
           request:
-            - set_host(request.url.host)
-            - set_header("X-Proxied-With", "bouncer")
+            - set_host(ctx, vars.request.url.host)
+            - set_header(ctx, "X-Proxied-With", "bouncer")

internal/command/server/dummy/index.gohtml

@@ -4,14 +4,14 @@
     <h2>Incoming headers</h2>
     <table style="width: 100%">
       <thead>
-        <tr>
+        <tr style="text-align: left">
           <th>Key</th>
           <th>Value</th>
         </tr>
       </thead>
       <tbody>
         {{ range $key, $val := .Request.Header }}
-        <tr>
+        <tr style="text-align: left">
           <td>
             <b>{{ $key }}</b>
           </td>
@@ -27,7 +27,7 @@
     <h2>Incoming cookies</h2>
     <table style="width: 100%">
       <thead>
-        <tr>
+        <tr style="text-align: left">
           <th>Name</th>
           <th>Domain</th>
           <th>Path</th>
@@ -41,7 +41,7 @@
       </thead>
       <tbody>
         {{ range $cookie := .Request.Cookies }}
-        <tr>
+        <tr style="text-align: left">
           <td>
             <b>{{ $cookie.Name }}</b>
           </td>

internal/proxy/director/layer/authn/layer.go

@@ -74,7 +74,7 @@ func (l *Layer) Middleware(layer *store.Layer) proxy.Middleware {
 				return
 			}
 
-			if err := l.applyRules(r, options, user); err != nil {
+			if err := l.applyRules(ctx, r, options, user); err != nil {
 				if errors.Is(err, ErrForbidden) {
 					l.renderForbiddenPage(w, r, layer, options, user)
 					return

internal/proxy/director/layer/authn/rules.go

@@ -1,6 +1,7 @@
 package authn
 
 import (
+	"context"
 	"net/http"
 
 	"forge.cadoles.com/cadoles/bouncer/internal/rule"
@@ -9,30 +10,32 @@ import (
 	"github.com/pkg/errors"
 )
 
-type Env struct {
+type Vars struct {
 	User *User `expr:"user"`
 }
 
-func (l *Layer) applyRules(r *http.Request, options *LayerOptions, user *User) error {
+func (l *Layer) applyRules(ctx context.Context, r *http.Request, options *LayerOptions, user *User) error {
 	rules := options.Rules
 	if len(rules) == 0 {
 		return nil
 	}
 
-	engine, err := rule.NewEngine[*Env](
+	engine, err := rule.NewEngine[*Vars](
 		rule.WithRules(options.Rules...),
 		rule.WithExpr(getAuthnAPI()...),
-		ruleHTTP.WithRequestFuncs(r),
+		ruleHTTP.WithRequestFuncs(),
 	)
 	if err != nil {
 		return errors.WithStack(err)
 	}
 
-	env := &Env{
+	vars := &Vars{
 		User: user,
 	}
 
-	if _, err := engine.Apply(env); err != nil {
+	ctx = ruleHTTP.WithRequest(ctx, r)
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
 		return errors.WithStack(err)
 	}
 

internal/proxy/director/layer/rewriter/layer.go

@@ -6,6 +6,9 @@ import (
 	proxy "forge.cadoles.com/Cadoles/go-proxy"
 	"forge.cadoles.com/Cadoles/go-proxy/wildcard"
 	"forge.cadoles.com/cadoles/bouncer/internal/proxy/director"
+	"forge.cadoles.com/cadoles/bouncer/internal/proxy/director/layer/util"
+	"forge.cadoles.com/cadoles/bouncer/internal/rule"
+	ruleHTTP "forge.cadoles.com/cadoles/bouncer/internal/rule/http"
 	"forge.cadoles.com/cadoles/bouncer/internal/store"
 	"github.com/pkg/errors"
 	"gitlab.com/wpetit/goweb/logger"
@@ -13,7 +16,10 @@ import (
 
 const LayerType store.LayerType = "rewriter"
 
-type Layer struct{}
+type Layer struct {
+	requestRuleEngine  *util.RevisionedRuleEngine[*RequestVars, *LayerOptions]
+	responseRuleEngine *util.RevisionedRuleEngine[*ResponseVars, *LayerOptions]
+}
 
 func (l *Layer) LayerType() store.LayerType {
 	return LayerType
@@ -39,7 +45,7 @@ func (l *Layer) Middleware(layer *store.Layer) proxy.Middleware {
 				return
 			}
 
-			if err := l.applyRequestRules(r, options); err != nil {
+			if err := l.applyRequestRules(ctx, r, layer.Revision, options); err != nil {
 				logger.Error(ctx, "could not apply request rules", logger.E(errors.WithStack(err)))
 				http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 
@@ -66,7 +72,9 @@ func (l *Layer) ResponseTransformer(layer *store.Layer) proxy.ResponseTransforme
 			return nil
 		}
 
-		if err := l.applyResponseRules(r, options); err != nil {
+		ctx := r.Request.Context()
+
+		if err := l.applyResponseRules(ctx, r, layer.Revision, options); err != nil {
 			return errors.WithStack(err)
 		}
 
@@ -75,7 +83,30 @@ func (l *Layer) ResponseTransformer(layer *store.Layer) proxy.ResponseTransforme
 }
 
 func New(funcs ...OptionFunc) *Layer {
-	return &Layer{}
+	return &Layer{
+		requestRuleEngine: util.NewRevisionedRuleEngine(func(options *LayerOptions) (*rule.Engine[*RequestVars], error) {
+			engine, err := rule.NewEngine[*RequestVars](
+				rule.WithRules(options.Rules.Request...),
+				ruleHTTP.WithRequestFuncs(),
+			)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			return engine, nil
+		}),
+		responseRuleEngine: util.NewRevisionedRuleEngine(func(options *LayerOptions) (*rule.Engine[*ResponseVars], error) {
+			engine, err := rule.NewEngine[*ResponseVars](
+				rule.WithRules(options.Rules.Response...),
+				ruleHTTP.WithResponseFuncs(),
+			)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			return engine, nil
+		}),
+	}
 }
 
 var (

internal/proxy/director/layer/rewriter/rules.go

@@ -1,68 +1,93 @@
 package rewriter
 
 import (
+	"context"
 	"net/http"
 
+	"forge.cadoles.com/cadoles/bouncer/internal/proxy/director"
 	"forge.cadoles.com/cadoles/bouncer/internal/rule"
 	ruleHTTP "forge.cadoles.com/cadoles/bouncer/internal/rule/http"
 	"github.com/pkg/errors"
 )
 
-type RequestEnv struct {
-	Request RequestInfo `expr:"request"`
+type RequestVars struct {
+	Request     RequestVar `expr:"request"`
+	OriginalURL URLVar     `expr:"original_url"`
 }
 
-type URLEnv struct {
-	Scheme      string      `expr:"scheme"`
-	Opaque      string      `expr:"opaque"`
-	User        UserInfoEnv `expr:"user"`
-	Host        string      `expr:"host"`
-	Path        string      `expr:"path"`
-	RawPath     string      `expr:"rawPath"`
-	RawQuery    string      `expr:"rawQuery"`
-	Fragment    string      `expr:"fragment"`
-	RawFragment string      `expr:"rawFragment"`
+type URLVar struct {
+	Scheme      string  `expr:"scheme"`
+	Opaque      string  `expr:"opaque"`
+	User        UserVar `expr:"user"`
+	Host        string  `expr:"host"`
+	Path        string  `expr:"path"`
+	RawPath     string  `expr:"raw_path"`
+	RawQuery    string  `expr:"raw_query"`
+	Fragment    string  `expr:"fragment"`
+	RawFragment string  `expr:"raw_fragment"`
 }
 
-type UserInfoEnv struct {
+type UserVar struct {
 	Username string `expr:"username"`
 	Password string `expr:"password"`
 }
 
-type RequestInfo struct {
+type RequestVar struct {
 	Method           string              `expr:"method"`
-	URL              URLEnv              `expr:"url"`
-	RawURL           string              `expr:"rawUrl"`
+	URL              URLVar              `expr:"url"`
+	RawURL           string              `expr:"raw_url"`
 	Proto            string              `expr:"proto"`
-	ProtoMajor       int                 `expr:"protoMajor"`
-	ProtoMinor       int                 `expr:"protoMinor"`
+	ProtoMajor       int                 `expr:"proto_major"`
+	ProtoMinor       int                 `expr:"proto_minor"`
 	Header           map[string][]string `expr:"header"`
-	ContentLength    int64               `expr:"contentLength"`
-	TransferEncoding []string            `expr:"transferEncoding"`
+	ContentLength    int64               `expr:"content_length"`
+	TransferEncoding []string            `expr:"transfer_encoding"`
 	Host             string              `expr:"host"`
 	Trailer          map[string][]string `expr:"trailer"`
-	RemoteAddr       string              `expr:"remoteAddr"`
-	RequestURI       string              `expr:"requestUri"`
+	RemoteAddr       string              `expr:"remote_addr"`
+	RequestURI       string              `expr:"request_uri"`
 }
 
-func (l *Layer) applyRequestRules(r *http.Request, options *LayerOptions) error {
+func (l *Layer) applyRequestRules(ctx context.Context, r *http.Request, layerRevision int, options *LayerOptions) error {
 	rules := options.Rules.Request
 	if len(rules) == 0 {
 		return nil
 	}
 
-	engine, err := l.getRequestRuleEngine(r, options)
+	engine, err := l.getRequestRuleEngine(ctx, layerRevision, options)
 	if err != nil {
 		return errors.WithStack(err)
 	}
 
-	env := &RequestEnv{
-		Request: RequestInfo{
+	originalURL, err := director.OriginalURL(ctx)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	vars := &RequestVars{
+		OriginalURL: URLVar{
+			Scheme: originalURL.Scheme,
+			Opaque: originalURL.Opaque,
+			User: UserVar{
+				Username: originalURL.User.Username(),
+				Password: func() string {
+					passwd, _ := originalURL.User.Password()
+					return passwd
+				}(),
+			},
+			Host:        originalURL.Host,
+			Path:        originalURL.Path,
+			RawPath:     originalURL.RawPath,
+			RawQuery:    originalURL.RawQuery,
+			Fragment:    originalURL.Fragment,
+			RawFragment: originalURL.RawFragment,
+		},
+		Request: RequestVar{
 			Method: r.Method,
-			URL: URLEnv{
+			URL: URLVar{
 				Scheme: r.URL.Scheme,
 				Opaque: r.URL.Opaque,
-				User: UserInfoEnv{
+				User: UserVar{
 					Username: r.URL.User.Username(),
 					Password: func() string {
 						passwd, _ := r.URL.User.Password()
@@ -90,18 +115,17 @@ func (l *Layer) applyRequestRules(r *http.Request, options *LayerOptions) error
 		},
 	}
 
-	if _, err := engine.Apply(env); err != nil {
+	ctx = ruleHTTP.WithRequest(ctx, r)
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
 		return errors.WithStack(err)
 	}
 
 	return nil
 }
 
-func (l *Layer) getRequestRuleEngine(r *http.Request, options *LayerOptions) (*rule.Engine[*RequestEnv], error) {
-	engine, err := rule.NewEngine[*RequestEnv](
-		rule.WithRules(options.Rules.Request...),
-		ruleHTTP.WithRequestFuncs(r),
-	)
+func (l *Layer) getRequestRuleEngine(ctx context.Context, layerRevision int, options *LayerOptions) (*rule.Engine[*RequestVars], error) {
+	engine, err := l.requestRuleEngine.Get(ctx, layerRevision, options)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
@@ -109,42 +133,65 @@ func (l *Layer) getRequestRuleEngine(r *http.Request, options *LayerOptions) (*r
 	return engine, nil
 }
 
-type ResponseEnv struct {
-	Request  RequestInfo  `expr:"request"`
-	Response ResponseInfo `expr:"response"`
+type ResponseVars struct {
+	OriginalURL URLVar      `expr:"original_url"`
+	Request     RequestVar  `expr:"request"`
+	Response    ResponseVar `expr:"response"`
 }
 
-type ResponseInfo struct {
+type ResponseVar struct {
 	Status           string              `expr:"status"`
-	StatusCode       int                 `expr:"statusCode"`
+	StatusCode       int                 `expr:"status_code"`
 	Proto            string              `expr:"proto"`
-	ProtoMajor       int                 `expr:"protoMajor"`
-	ProtoMinor       int                 `expr:"protoMinor"`
+	ProtoMajor       int                 `expr:"proto_major"`
+	ProtoMinor       int                 `expr:"proto_minor"`
 	Header           map[string][]string `expr:"header"`
-	ContentLength    int64               `expr:"contentLength"`
-	TransferEncoding []string            `expr:"transferEncoding"`
+	ContentLength    int64               `expr:"content_length"`
+	TransferEncoding []string            `expr:"transfer_encoding"`
 	Uncompressed     bool                `expr:"uncompressed"`
 	Trailer          map[string][]string `expr:"trailer"`
 }
 
-func (l *Layer) applyResponseRules(r *http.Response, options *LayerOptions) error {
+func (l *Layer) applyResponseRules(ctx context.Context, r *http.Response, layerRevision int, options *LayerOptions) error {
 	rules := options.Rules.Response
 	if len(rules) == 0 {
 		return nil
 	}
 
-	engine, err := l.getResponseRuleEngine(r, options)
+	engine, err := l.getResponseRuleEngine(ctx, layerRevision, options)
 	if err != nil {
 		return errors.WithStack(err)
 	}
 
-	env := &ResponseEnv{
-		Request: RequestInfo{
+	originalURL, err := director.OriginalURL(ctx)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	vars := &ResponseVars{
+		OriginalURL: URLVar{
+			Scheme: originalURL.Scheme,
+			Opaque: originalURL.Opaque,
+			User: UserVar{
+				Username: originalURL.User.Username(),
+				Password: func() string {
+					passwd, _ := originalURL.User.Password()
+					return passwd
+				}(),
+			},
+			Host:        originalURL.Host,
+			Path:        originalURL.Path,
+			RawPath:     originalURL.RawPath,
+			RawQuery:    originalURL.RawQuery,
+			Fragment:    originalURL.Fragment,
+			RawFragment: originalURL.RawFragment,
+		},
+		Request: RequestVar{
 			Method: r.Request.Method,
-			URL: URLEnv{
+			URL: URLVar{
 				Scheme: r.Request.URL.Scheme,
 				Opaque: r.Request.URL.Opaque,
-				User: UserInfoEnv{
+				User: UserVar{
 					Username: r.Request.URL.User.Username(),
 					Password: func() string {
 						passwd, _ := r.Request.URL.User.Password()
@@ -170,7 +217,7 @@ func (l *Layer) applyResponseRules(r *http.Response, options *LayerOptions) erro
 			RemoteAddr:       r.Request.RemoteAddr,
 			RequestURI:       r.Request.RequestURI,
 		},
-		Response: ResponseInfo{
+		Response: ResponseVar{
 			Proto:            r.Proto,
 			ProtoMajor:       r.ProtoMajor,
 			ProtoMinor:       r.ProtoMinor,
@@ -183,18 +230,17 @@ func (l *Layer) applyResponseRules(r *http.Response, options *LayerOptions) erro
 		},
 	}
 
-	if _, err := engine.Apply(env); err != nil {
+	ctx = ruleHTTP.WithResponse(ctx, r)
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
 		return errors.WithStack(err)
 	}
 
 	return nil
 }
 
-func (l *Layer) getResponseRuleEngine(r *http.Response, options *LayerOptions) (*rule.Engine[*ResponseEnv], error) {
-	engine, err := rule.NewEngine[*ResponseEnv](
-		rule.WithRules(options.Rules.Response...),
-		ruleHTTP.WithResponseFuncs(r),
-	)
+func (l *Layer) getResponseRuleEngine(ctx context.Context, layerRevision int, options *LayerOptions) (*rule.Engine[*ResponseVars], error) {
+	engine, err := l.responseRuleEngine.Get(ctx, layerRevision, options)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}

internal/proxy/director/layer/util/revisioned_rule_engine.go

@@ -0,0 +1,51 @@
+package util
+
+import (
+	"context"
+	"sync"
+
+	"forge.cadoles.com/cadoles/bouncer/internal/rule"
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/logger"
+)
+
+type RuleEngineFactoryFunc[V any, O any] func(ops O) (*rule.Engine[V], error)
+
+type RevisionedRuleEngine[V any, O any] struct {
+	mutex    sync.RWMutex
+	revision int
+	engine   *rule.Engine[V]
+	factory  RuleEngineFactoryFunc[V, O]
+}
+
+func (e *RevisionedRuleEngine[V, O]) Get(ctx context.Context, revision int, opts O) (*rule.Engine[V], error) {
+	e.mutex.RLock()
+	if revision == e.revision {
+		logger.Debug(ctx, "using cached rule engine", logger.F("layerRevision", revision))
+
+		defer e.mutex.RUnlock()
+		return e.engine, nil
+	}
+	e.mutex.RUnlock()
+
+	e.mutex.Lock()
+	defer e.mutex.Unlock()
+
+	logger.Debug(ctx, "creating rule engine", logger.F("layerRevision", revision))
+
+	engine, err := e.factory(opts)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	e.engine = engine
+	e.revision = revision
+
+	return engine, nil
+}
+
+func NewRevisionedRuleEngine[V any, O any](factory RuleEngineFactoryFunc[V, O]) *RevisionedRuleEngine[V, O] {
+	return &RevisionedRuleEngine[V, O]{
+		factory: factory,
+	}
+}

internal/rule/engine.go

@@ -1,16 +1,28 @@
 package rule
 
 import (
+	"context"
+
 	"github.com/expr-lang/expr"
 	"github.com/expr-lang/expr/vm"
 	"github.com/pkg/errors"
 )
 
-type Engine[E any] struct {
+type Engine[V any] struct {
 	rules []*vm.Program
 }
 
-func (e *Engine[E]) Apply(env E) ([]any, error) {
+func (e *Engine[V]) Apply(ctx context.Context, vars V) ([]any, error) {
+	type Env[V any] struct {
+		Context context.Context `expr:"ctx"`
+		Vars    V               `expr:"vars"`
+	}
+
+	env := Env[V]{
+		Context: ctx,
+		Vars:    vars,
+	}
+
 	results := make([]any, 0, len(e.rules))
 	for i, r := range e.rules {
 		result, err := expr.Run(r, env)
@@ -42,3 +54,26 @@ func NewEngine[E any](funcs ...OptionFunc) (*Engine[E], error) {
 
 	return engine, nil
 }
+
+func Context[T any](ctx context.Context, key any) (T, bool) {
+	raw := ctx.Value(key)
+	if raw == nil {
+		return *new(T), false
+	}
+
+	value, err := Assert[T](raw)
+	if err != nil {
+		return *new(T), false
+	}
+
+	return value, true
+}
+
+func Assert[T any](raw any) (T, error) {
+	value, ok := raw.(T)
+	if !ok {
+		return *new(T), errors.Errorf("unexpected value '%T'", value)
+	}
+
+	return value, nil
+}

internal/rule/http/context.go

@@ -0,0 +1,31 @@
+package http
+
+import (
+	"context"
+	"net/http"
+
+	"forge.cadoles.com/cadoles/bouncer/internal/rule"
+)
+
+type contextKey string
+
+const (
+	contextKeyRequest  contextKey = "request"
+	contextKeyResponse contextKey = "response"
+)
+
+func WithRequest(ctx context.Context, r *http.Request) context.Context {
+	return context.WithValue(ctx, contextKeyRequest, r)
+}
+
+func WithResponse(ctx context.Context, r *http.Response) context.Context {
+	return context.WithValue(ctx, contextKeyResponse, r)
+}
+
+func ctxRequest(ctx context.Context) (*http.Request, bool) {
+	return rule.Context[*http.Request](ctx, contextKeyRequest)
+}
+
+func ctxResponse(ctx context.Context) (*http.Response, bool) {
+	return rule.Context[*http.Response](ctx, contextKeyResponse)
+}

internal/rule/http/option.go

@@ -1,20 +1,18 @@
 package http
 
 import (
-	"net/http"
-
 	"forge.cadoles.com/cadoles/bouncer/internal/rule"
 	"github.com/expr-lang/expr"
 )
 
-func WithRequestFuncs(r *http.Request) rule.OptionFunc {
+func WithRequestFuncs() rule.OptionFunc {
 	return func(opts *rule.Options) {
 		funcs := []expr.Option{
-			setRequestURL(r),
-			setRequestHeaderFunc(r),
-			addRequestHeaderFunc(r),
-			delRequestHeadersFunc(r),
-			setRequestHostFunc(r),
+			setRequestURLFunc(),
+			setRequestHeaderFunc(),
+			addRequestHeaderFunc(),
+			delRequestHeadersFunc(),
+			setRequestHostFunc(),
 		}
 
 		if len(opts.Expr) == 0 {
@@ -25,12 +23,12 @@ func WithRequestFuncs(r *http.Request) rule.OptionFunc {
 	}
 }
 
-func WithResponseFuncs(r *http.Response) rule.OptionFunc {
+func WithResponseFuncs() rule.OptionFunc {
 	return func(opts *rule.Options) {
 		funcs := []expr.Option{
-			setResponseHeaderFunc(r),
-			addResponseHeaderFunc(r),
-			delResponseHeadersFunc(r),
+			setResponseHeaderFunc(),
+			addResponseHeaderFunc(),
+			delResponseHeadersFunc(),
 		}
 
 		if len(opts.Expr) == 0 {

internal/rule/http/request.go

@@ -1,109 +1,155 @@
 package http
 
 import (
+	"context"
 	"fmt"
-	"net/http"
 	"net/url"
 	"strconv"
 	"strings"
 	"time"
 
 	"forge.cadoles.com/Cadoles/go-proxy/wildcard"
+	"forge.cadoles.com/cadoles/bouncer/internal/rule"
 	"github.com/expr-lang/expr"
 	"github.com/pkg/errors"
 )
 
-func setRequestHostFunc(r *http.Request) expr.Option {
+func setRequestHostFunc() expr.Option {
 	return expr.Function(
 		"set_host",
 		func(params ...any) (any, error) {
-			host := params[0].(string)
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			host, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			r, ok := ctxRequest(ctx)
+			if !ok {
+				return nil, errors.New("could not find http request in context")
+			}
+
 			r.Host = host
 
 			return true, nil
 		},
-		new(func(string) bool),
+		new(func(context.Context, string) bool),
 	)
 }
 
-func setRequestURL(r *http.Request) expr.Option {
+func setRequestURLFunc() expr.Option {
 	return expr.Function(
 		"set_url",
 		func(params ...any) (any, error) {
-			rawURL := params[0].(string)
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			rawURL, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
 
 			url, err := url.Parse(rawURL)
 			if err != nil {
 				return false, errors.WithStack(err)
 			}
 
+			r, ok := ctxRequest(ctx)
+			if !ok {
+				return nil, errors.New("could not find http request in context")
+			}
+
 			r.URL = url
 
 			return true, nil
 		},
-		new(func(string) bool),
+		new(func(context.Context, string) bool),
 	)
 }
 
-func addRequestHeaderFunc(r *http.Request) expr.Option {
+func addRequestHeaderFunc() expr.Option {
 	return expr.Function(
 		"add_header",
 		func(params ...any) (any, error) {
-			name := params[0].(string)
-			rawValue := params[1]
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
 
-			var value string
-			switch v := rawValue.(type) {
-			case []string:
-				value = strings.Join(v, ",")
-			case time.Time:
-				value = strconv.FormatInt(v.UTC().Unix(), 10)
-			case time.Duration:
-				value = strconv.FormatInt(int64(v.Seconds()), 10)
-			default:
-				value = fmt.Sprintf("%v", rawValue)
+			name, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			value := formatValue(params[2])
+
+			r, ok := ctxRequest(ctx)
+			if !ok {
+				return nil, errors.New("could not find http request in context")
 			}
 
 			r.Header.Add(name, value)
 
 			return true, nil
 		},
-		new(func(string, string) bool),
+		new(func(context.Context, string, string) bool),
 	)
 }
 
-func setRequestHeaderFunc(r *http.Request) expr.Option {
+func setRequestHeaderFunc() expr.Option {
 	return expr.Function(
 		"set_header",
 		func(params ...any) (any, error) {
-			name := params[0].(string)
-			rawValue := params[1]
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
 
-			var value string
-			switch v := rawValue.(type) {
-			case []string:
-				value = strings.Join(v, ",")
-			case time.Time:
-				value = strconv.FormatInt(v.UTC().Unix(), 10)
-			case time.Duration:
-				value = strconv.FormatInt(int64(v.Seconds()), 10)
-			default:
-				value = fmt.Sprintf("%v", rawValue)
+			name, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			value := formatValue(params[2])
+
+			r, ok := ctxRequest(ctx)
+			if !ok {
+				return nil, errors.New("could not find http request in context")
 			}
 
 			r.Header.Set(name, value)
 
 			return true, nil
 		},
-		new(func(string, string) bool),
+		new(func(context.Context, string, string) bool),
 	)
 }
 
-func delRequestHeadersFunc(r *http.Request) expr.Option {
+func delRequestHeadersFunc() expr.Option {
 	return expr.Function(
 		"del_headers",
 		func(params ...any) (any, error) {
-			pattern := params[0].(string)
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			pattern, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			r, ok := ctxRequest(ctx)
+			if !ok {
+				return nil, errors.New("could not find http request in context")
+			}
+
 			deleted := false
 
 			for key := range r.Header {
@@ -117,6 +163,21 @@ func delRequestHeadersFunc(r *http.Request) expr.Option {
 
 			return deleted, nil
 		},
-		new(func(string) bool),
+		new(func(context.Context, string) bool),
 	)
 }
+
+func formatValue(v any) string {
+	var value string
+	switch v := v.(type) {
+	case []string:
+		value = strings.Join(v, ",")
+	case time.Time:
+		value = strconv.FormatInt(v.UTC().Unix(), 10)
+	case time.Duration:
+		value = strconv.FormatInt(int64(v.Seconds()), 10)
+	default:
+		value = fmt.Sprintf("%v", v)
+	}
+	return value
+}

internal/rule/http/request_test.go

@@ -0,0 +1,195 @@
+package http
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"forge.cadoles.com/cadoles/bouncer/internal/rule"
+	"github.com/pkg/errors"
+)
+
+func TestSetRequestHost(t *testing.T) {
+	type Vars struct {
+		NewHost string `expr:"newHost"`
+	}
+
+	engine := createRuleEngine[Vars](t,
+		rule.WithExpr(setRequestHostFunc()),
+		rule.WithRules(
+			"set_host(ctx, vars.newHost)",
+		),
+	)
+
+	req, err := http.NewRequest("GET", "http://example.net", nil)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	ctx := context.Background()
+
+	ctx = WithRequest(ctx, req)
+
+	vars := Vars{
+		NewHost: "foobar",
+	}
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	if e, g := vars.NewHost, req.Host; e != g {
+		t.Errorf("req.Host: expected '%v', got '%v'", e, g)
+	}
+}
+
+func TestSetRequestURL(t *testing.T) {
+	type Vars struct {
+		NewURL string `expr:"newURL"`
+	}
+
+	engine := createRuleEngine[Vars](t,
+		rule.WithExpr(setRequestURLFunc()),
+		rule.WithRules(
+			"set_url(ctx, vars.newURL)",
+		),
+	)
+
+	req, err := http.NewRequest("GET", "http://example.net", nil)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	ctx := context.Background()
+
+	ctx = WithRequest(ctx, req)
+
+	vars := Vars{
+		NewURL: "http://localhost",
+	}
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	if e, g := vars.NewURL, req.URL.String(); e != g {
+		t.Errorf("req.URL.String(): expected '%v', got '%v'", e, g)
+	}
+}
+
+func TestAddRequestHeader(t *testing.T) {
+	type Vars struct {
+		NewHeaderKey   string `expr:"newHeaderKey"`
+		NewHeaderValue string `expr:"newHeaderValue"`
+	}
+
+	engine := createRuleEngine[Vars](t,
+		rule.WithExpr(addRequestHeaderFunc()),
+		rule.WithRules(
+			"add_header(ctx, vars.newHeaderKey, vars.newHeaderValue)",
+		),
+	)
+
+	req, err := http.NewRequest("GET", "http://example.net", nil)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	ctx := context.Background()
+
+	ctx = WithRequest(ctx, req)
+
+	vars := Vars{
+		NewHeaderKey:   "X-My-Header",
+		NewHeaderValue: "foobar",
+	}
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	if e, g := vars.NewHeaderValue, req.Header.Get(vars.NewHeaderKey); e != g {
+		t.Errorf("req.Header.Get(vars.NewHeaderKey): expected '%v', got '%v'", e, g)
+	}
+}
+
+func TestSetRequestHeader(t *testing.T) {
+	type Vars struct {
+		HeaderKey   string `expr:"headerKey"`
+		HeaderValue string `expr:"headerValue"`
+	}
+
+	engine := createRuleEngine[Vars](t,
+		rule.WithExpr(setRequestHeaderFunc()),
+		rule.WithRules(
+			"set_header(ctx, vars.headerKey, vars.headerValue)",
+		),
+	)
+
+	req, err := http.NewRequest("GET", "http://example.net", nil)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	vars := Vars{
+		HeaderKey:   "X-My-Header",
+		HeaderValue: "foobar",
+	}
+
+	req.Header.Set(vars.HeaderKey, "test")
+
+	ctx := context.Background()
+	ctx = WithRequest(ctx, req)
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	if e, g := vars.HeaderValue, req.Header.Get(vars.HeaderKey); e != g {
+		t.Errorf("req.Header.Get(vars.HeaderKey): expected '%v', got '%v'", e, g)
+	}
+}
+
+func TestDelRequestHeaders(t *testing.T) {
+	type Vars struct {
+		HeaderPattern string `expr:"headerPattern"`
+	}
+
+	engine := createRuleEngine[Vars](t,
+		rule.WithExpr(delRequestHeadersFunc()),
+		rule.WithRules(
+			"del_headers(ctx, vars.headerPattern)",
+		),
+	)
+
+	req, err := http.NewRequest("GET", "http://example.net", nil)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	vars := Vars{
+		HeaderPattern: "X-My-*",
+	}
+
+	req.Header.Set("X-My-Header", "test")
+
+	ctx := context.Background()
+	ctx = WithRequest(ctx, req)
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	if val := req.Header.Get("X-My-Header"); val != "" {
+		t.Errorf("req.Header.Get(\"X-My-Header\") should be empty, got '%v'", val)
+	}
+}
+
+func createRuleEngine[V any](t *testing.T, funcs ...rule.OptionFunc) *rule.Engine[V] {
+	engine, err := rule.NewEngine[V](funcs...)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	return engine
+}

internal/rule/http/response.go

@@ -1,22 +1,33 @@
 package http
 
 import (
+	"context"
 	"fmt"
-	"net/http"
 	"strconv"
 	"strings"
 	"time"
 
 	"forge.cadoles.com/Cadoles/go-proxy/wildcard"
+	"forge.cadoles.com/cadoles/bouncer/internal/rule"
 	"github.com/expr-lang/expr"
+	"github.com/pkg/errors"
 )
 
-func addResponseHeaderFunc(r *http.Response) expr.Option {
+func addResponseHeaderFunc() expr.Option {
 	return expr.Function(
 		"add_header",
 		func(params ...any) (any, error) {
-			name := params[0].(string)
-			rawValue := params[1]
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			name, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			rawValue := params[2]
 
 			var value string
 			switch v := rawValue.(type) {
@@ -30,20 +41,34 @@ func addResponseHeaderFunc(r *http.Response) expr.Option {
 				value = fmt.Sprintf("%v", rawValue)
 			}
 
+			r, ok := ctxResponse(ctx)
+			if !ok {
+				return nil, errors.New("could not find http response in context")
+			}
+
 			r.Header.Add(name, value)
 
 			return true, nil
 		},
-		new(func(string, string) bool),
+		new(func(context.Context, string, string) bool),
 	)
 }
 
-func setResponseHeaderFunc(r *http.Response) expr.Option {
+func setResponseHeaderFunc() expr.Option {
 	return expr.Function(
 		"set_header",
 		func(params ...any) (any, error) {
-			name := params[0].(string)
-			rawValue := params[1]
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			name, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			rawValue := params[2]
 
 			var value string
 			switch v := rawValue.(type) {
@@ -57,19 +82,38 @@ func setResponseHeaderFunc(r *http.Response) expr.Option {
 				value = fmt.Sprintf("%v", rawValue)
 			}
 
+			r, ok := ctxResponse(ctx)
+			if !ok {
+				return nil, errors.New("could not find http response in context")
+			}
+
 			r.Header.Set(name, value)
 
 			return true, nil
 		},
-		new(func(string, string) bool),
+		new(func(context.Context, string, string) bool),
 	)
 }
 
-func delResponseHeadersFunc(r *http.Response) expr.Option {
+func delResponseHeadersFunc() expr.Option {
 	return expr.Function(
 		"del_headers",
 		func(params ...any) (any, error) {
-			pattern := params[0].(string)
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			pattern, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			r, ok := ctxResponse(ctx)
+			if !ok {
+				return nil, errors.New("could not find http response in context")
+			}
+
 			deleted := false
 
 			for key := range r.Header {
@@ -83,6 +127,6 @@ func delResponseHeadersFunc(r *http.Response) expr.Option {
 
 			return deleted, nil
 		},
-		new(func(string) bool),
+		new(func(context.Context, string) bool),
 	)
 }

internal/rule/http/response_test.go

@@ -0,0 +1,139 @@
+package http
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"testing"
+
+	"forge.cadoles.com/cadoles/bouncer/internal/rule"
+	"github.com/pkg/errors"
+)
+
+func TestAddResponseHeader(t *testing.T) {
+	type Vars struct {
+		NewHeaderKey   string `expr:"newHeaderKey"`
+		NewHeaderValue string `expr:"newHeaderValue"`
+	}
+
+	engine := createRuleEngine[Vars](t,
+		rule.WithExpr(addResponseHeaderFunc()),
+		rule.WithRules(
+			"add_header(ctx, vars.newHeaderKey, vars.newHeaderValue)",
+		),
+	)
+
+	req, err := http.NewRequest("GET", "http://example.net", nil)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	resp := createResponse(req, http.StatusOK, nil)
+
+	ctx := context.Background()
+
+	ctx = WithResponse(ctx, resp)
+
+	vars := Vars{
+		NewHeaderKey:   "X-My-Header",
+		NewHeaderValue: "foobar",
+	}
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	if e, g := vars.NewHeaderValue, resp.Header.Get(vars.NewHeaderKey); e != g {
+		t.Errorf("resp.Header.Get(vars.NewHeaderKey): expected '%v', got '%v'", e, g)
+	}
+}
+
+func TestResponseSetHeader(t *testing.T) {
+	type Vars struct {
+		HeaderKey   string `expr:"headerKey"`
+		HeaderValue string `expr:"headerValue"`
+	}
+
+	engine := createRuleEngine[Vars](t,
+		rule.WithExpr(setResponseHeaderFunc()),
+		rule.WithRules(
+			"set_header(ctx, vars.headerKey, vars.headerValue)",
+		),
+	)
+
+	req, err := http.NewRequest("GET", "http://example.net", nil)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	resp := createResponse(req, http.StatusOK, nil)
+
+	vars := Vars{
+		HeaderKey:   "X-My-Header",
+		HeaderValue: "foobar",
+	}
+
+	resp.Header.Set(vars.HeaderKey, "test")
+
+	ctx := context.Background()
+	ctx = WithResponse(ctx, resp)
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	if e, g := vars.HeaderValue, resp.Header.Get(vars.HeaderKey); e != g {
+		t.Errorf("resp.Header.Get(vars.HeaderKey): expected '%v', got '%v'", e, g)
+	}
+}
+
+func TestResponseDelHeaders(t *testing.T) {
+	type Vars struct {
+		HeaderPattern string `expr:"headerPattern"`
+	}
+
+	engine := createRuleEngine[Vars](t,
+		rule.WithExpr(delResponseHeadersFunc()),
+		rule.WithRules(
+			"del_headers(ctx, vars.headerPattern)",
+		),
+	)
+
+	req, err := http.NewRequest("GET", "http://example.net", nil)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	resp := createResponse(req, http.StatusOK, nil)
+
+	vars := Vars{
+		HeaderPattern: "X-My-*",
+	}
+
+	resp.Header.Set("X-My-Header", "test")
+
+	ctx := context.Background()
+	ctx = WithResponse(ctx, resp)
+
+	if _, err := engine.Apply(ctx, vars); err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	if val := resp.Header.Get("X-My-Header"); val != "" {
+		t.Errorf("resp.Header.Get(\"X-My-Header\") should be empty, got '%v'", val)
+	}
+}
+
+func createResponse(req *http.Request, statusCode int, body io.Reader) *http.Response {
+	return &http.Response{
+		Status:        http.StatusText(statusCode),
+		StatusCode:    statusCode,
+		Proto:         "HTTP/1.1",
+		ProtoMajor:    1,
+		ProtoMinor:    1,
+		Body:          io.NopCloser(body),
+		ContentLength: -1,
+		Request:       req,
+		Header:        make(http.Header, 0),
+	}
+}