Initial implementation of JavaScript Filter

.github/workflows/commit.yaml

@@ -97,7 +97,7 @@ jobs:
             ~/go/bin
           key: go-test-${{ hashFiles('**/go.mod', '**/go.sum') }}
 
-      - run: go test ./... -v
+      - run: CGO_ENABLED=0 go test ./... -v
       - run: go build -buildmode=c-shared -o main.so
       - run: go tool golangci-lint run
 

go/go.mod

@@ -46,6 +46,8 @@ require (
 	github.com/daixiang0/gci v0.13.5 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/denis-tingaikin/go-header v0.5.0 // indirect
+	github.com/dlclark/regexp2 v1.11.4 // indirect
+	github.com/dop251/goja v0.0.0-20250630131328-58d95d85e994 // indirect
 	github.com/ettle/strcase v0.2.0 // indirect
 	github.com/fatih/color v1.18.0 // indirect
 	github.com/fatih/structtag v1.2.0 // indirect
@@ -54,6 +56,7 @@ require (
 	github.com/fzipp/gocyclo v0.6.0 // indirect
 	github.com/ghostiam/protogetter v0.3.9 // indirect
 	github.com/go-critic/go-critic v0.12.0 // indirect
+	github.com/go-sourcemap/sourcemap v2.1.3+incompatible // indirect
 	github.com/go-toolsmith/astcast v1.1.0 // indirect
 	github.com/go-toolsmith/astcopy v1.1.0 // indirect
 	github.com/go-toolsmith/astequal v1.2.0 // indirect
@@ -75,6 +78,7 @@ require (
 	github.com/golangci/revgrep v0.8.0 // indirect
 	github.com/golangci/unconvert v0.0.0-20240309020433-c5143eacb3ed // indirect
 	github.com/google/go-cmp v0.7.0 // indirect
+	github.com/google/pprof v0.0.0-20241210010833-40e02aabc2ad // indirect
 	github.com/gordonklaus/ineffassign v0.1.0 // indirect
 	github.com/gostaticanalysis/analysisutil v0.7.1 // indirect
 	github.com/gostaticanalysis/comment v1.5.0 // indirect

go/go.sum

@@ -134,6 +134,10 @@ github.com/denis-tingaikin/go-header v0.5.0 h1:SRdnP5ZKvcO9KKRP1KJrhFR3RrlGuD+42
 github.com/denis-tingaikin/go-header v0.5.0/go.mod h1:mMenU5bWrok6Wl2UsZjy+1okegmwQ3UgWl4V1D8gjlY=
 github.com/dlclark/regexp2 v1.11.0 h1:G/nrcoOa7ZXlpoa/91N3X7mM3r8eIlMBBJZvsz/mxKI=
 github.com/dlclark/regexp2 v1.11.0/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
+github.com/dlclark/regexp2 v1.11.4 h1:rPYF9/LECdNymJufQKmri9gV604RvvABwgOA8un7yAo=
+github.com/dlclark/regexp2 v1.11.4/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
+github.com/dop251/goja v0.0.0-20250630131328-58d95d85e994 h1:aQYWswi+hRL2zJqGacdCZx32XjKYV8ApXFGntw79XAM=
+github.com/dop251/goja v0.0.0-20250630131328-58d95d85e994/go.mod h1:MxLav0peU43GgvwVgNbLAj1s/bSGboKkhuULvq/7hx4=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
@@ -169,6 +173,8 @@ github.com/go-logr/logr v1.4.2 h1:6pFjapn8bFcIbiKo3XT4j/BhANplGihG6tvd+8rYgrY=
 github.com/go-logr/logr v1.4.2/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
 github.com/go-quicktest/qt v1.101.0 h1:O1K29Txy5P2OK0dGo59b7b0LR6wKfIhttaAhHUyn7eI=
 github.com/go-quicktest/qt v1.101.0/go.mod h1:14Bz/f7NwaXPtdYEgzsx46kqSxVwTbzVZsDC26tQJow=
+github.com/go-sourcemap/sourcemap v2.1.3+incompatible h1:W1iEw64niKVGogNgBN3ePyLFfuisuzeidWPMPWmECqU=
+github.com/go-sourcemap/sourcemap v2.1.3+incompatible/go.mod h1:F8jJfvm2KbVjc5NqelyYJmf/v5J0dwNLS2mL4sNA1Jg=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/go-task/slim-sprig/v3 v3.0.0 h1:sUs3vkvUymDpBKi3qH1YSqBQk9+9D/8M2mN1vB6EwHI=
 github.com/go-task/slim-sprig/v3 v3.0.0/go.mod h1:W848ghGpv3Qj3dhTPRyJypKRiqCdHZiAzKg9hl15HA8=

go/javascript.go

@@ -0,0 +1,205 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"math/rand"
+	"os"
+	"sync"
+
+	"github.com/dop251/goja"
+	"github.com/envoyproxy/dynamic-modules-examples/go/gosdk"
+)
+
+const (
+	javaScriptExportedSymbolOnConfig          = "OnConfigure"
+	javaScriptExportedSymbolOnRequestHeaders  = "OnRequestHeaders"
+	javaScriptExportedSymbolOnResponseHeaders = "OnResponseHeaders"
+
+	functionDeclTemplate = `globalThis.%[1]s = %[1]s`
+	numberOfVMPool       = 24
+)
+
+type (
+	// javaScriptFilterConfig implements [gosdk.HttpFilterConfig].
+	javaScriptFilterConfig struct {
+		vms [numberOfVMPool]*javaScriptVM
+	}
+	// javaScriptFilter implements [gosdk.HttpFilter].
+	javaScriptFilter struct {
+		vm              *javaScriptVM
+		requestHeaders  map[string]string
+		responseHeaders map[string]string
+	}
+	javaScriptVM struct {
+		*goja.Runtime
+		mux               sync.Mutex
+		onRequestHeaders  goja.Callable
+		onResponseHeaders goja.Callable
+	}
+)
+
+func newJavaScriptFilterConfig(userCode string) gosdk.HttpFilterConfig {
+	c := &javaScriptFilterConfig{}
+
+	for i := range numberOfVMPool {
+		vm, err := newJavaScriptVM(userCode, os.Stdout)
+		if err != nil {
+			log.Printf("failed to create JavaScript VM: %v", err)
+			return nil
+		}
+		c.vms[i] = vm
+	}
+	return c
+}
+
+func newJavaScriptVM(script string, w io.Writer) (*javaScriptVM, error) {
+	vm := goja.New()
+	console := vm.NewObject()
+	err := console.Set("log", func(call goja.FunctionCall) goja.Value {
+		args := make([]interface{}, 0, len(call.Arguments))
+		for _, a := range call.Arguments {
+			args = append(args, a.Export())
+		}
+		_, _ = fmt.Fprint(w, args...)
+		return goja.Undefined()
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to set console.log: %w", err)
+	}
+	err = vm.Set("console", console)
+	if err != nil {
+		return nil, fmt.Errorf("failed to set console: %w", err)
+	}
+
+	_, err = vm.RunString(script)
+	if err != nil {
+		return nil, fmt.Errorf("failed to run script: %w", err)
+	}
+
+	// Call OnConfigure.
+	onConfigure, ok := goja.AssertFunction(vm.GlobalObject().Get(javaScriptExportedSymbolOnConfig))
+	if !ok {
+		return nil, fmt.Errorf("failed to get %s function", javaScriptExportedSymbolOnConfig)
+	}
+	_, err = onConfigure(goja.Undefined())
+	if err != nil {
+		return nil, fmt.Errorf("failed to call %s function: %w", javaScriptExportedSymbolOnConfig, err)
+	}
+
+	ret := &javaScriptVM{Runtime: vm}
+	// Check two exported functions.
+	ret.onRequestHeaders, ok = goja.AssertFunction(vm.GlobalObject().Get(javaScriptExportedSymbolOnRequestHeaders))
+	if !ok {
+		return nil, fmt.Errorf("failed to get %s function", javaScriptExportedSymbolOnRequestHeaders)
+	}
+	ret.onResponseHeaders, ok = goja.AssertFunction(vm.GlobalObject().Get(javaScriptExportedSymbolOnResponseHeaders))
+	if !ok {
+		return nil, fmt.Errorf("failed to get %s function", javaScriptExportedSymbolOnResponseHeaders)
+	}
+	return ret, nil
+}
+
+// NewFilter implements [gosdk.HttpFilterConfig].
+func (p *javaScriptFilterConfig) NewFilter() gosdk.HttpFilter {
+	vm := p.vms[rand.Intn(numberOfVMPool)]
+	return &javaScriptFilter{vm: vm, requestHeaders: make(map[string]string), responseHeaders: make(map[string]string)}
+}
+
+// RequestHeaders implements [gosdk.HttpFilter].
+func (p *javaScriptFilter) RequestHeaders(e gosdk.EnvoyHttpFilter, _ bool) gosdk.RequestHeadersStatus {
+	headers := e.GetRequestHeaders()
+	for k, vs := range headers {
+		p.requestHeaders[k] = vs[0]
+	}
+	p.vm.mux.Lock()
+	defer p.vm.mux.Unlock()
+	vm := p.vm
+	obj := vm.NewObject()
+	_ = obj.Set("getRequestHeader", func(call goja.FunctionCall) goja.Value {
+		if len(call.Arguments) < 1 {
+			return vm.ToValue("")
+		}
+		key := call.Argument(0).String()
+		return vm.ToValue(p.requestHeaders[key])
+	})
+	_ = obj.Set("setRequestHeader", func(call goja.FunctionCall) goja.Value {
+		if len(call.Arguments) < 2 {
+			return goja.Undefined()
+		}
+		key := call.Argument(0).String()
+		value := call.Argument(1).String()
+		p.requestHeaders[key] = value
+		e.SetRequestHeader(key, []byte(value))
+		return goja.Undefined()
+	})
+	if _, err := vm.onRequestHeaders(goja.Undefined(), obj); err != nil {
+		log.Printf("failed to call %s: %v", javaScriptExportedSymbolOnRequestHeaders, err)
+		return gosdk.RequestHeadersStatusStopIteration
+	}
+	return gosdk.RequestHeadersStatusContinue
+}
+
+// ResponseHeaders implements [gosdk.HttpFilter].
+func (p *javaScriptFilter) ResponseHeaders(e gosdk.EnvoyHttpFilter, _ bool) gosdk.ResponseHeadersStatus {
+	headers := e.GetResponseHeaders()
+	for k, vs := range headers {
+		p.responseHeaders[k] = vs[0]
+	}
+	p.vm.mux.Lock()
+	defer p.vm.mux.Unlock()
+	vm := p.vm
+	obj := vm.NewObject()
+	_ = obj.Set("getRequestHeader", func(call goja.FunctionCall) goja.Value {
+		if len(call.Arguments) < 1 {
+			return vm.ToValue("")
+		}
+		key := call.Argument(0).String()
+		return vm.ToValue(p.requestHeaders[key])
+	})
+
+	// Setting request header in response phase is not allowed.
+
+	_ = obj.Set("getResponseHeader", func(call goja.FunctionCall) goja.Value {
+		if len(call.Arguments) < 1 {
+			return vm.ToValue("")
+		}
+		key := call.Argument(0).String()
+		return vm.ToValue(p.responseHeaders[key])
+	})
+	_ = obj.Set("setResponseHeader", func(call goja.FunctionCall) goja.Value {
+		if len(call.Arguments) < 2 {
+			return goja.Undefined()
+		}
+		key := call.Argument(0).String()
+		value := call.Argument(1).String()
+		p.responseHeaders[key] = value
+		e.SetResponseHeader(key, []byte(value))
+		return goja.Undefined()
+	})
+	if _, err := vm.onResponseHeaders(goja.Undefined(), obj); err != nil {
+		log.Printf("failed to call %s: %v", javaScriptExportedSymbolOnResponseHeaders, err)
+		return gosdk.ResponseHeadersStatusStopIteration
+	}
+	return gosdk.ResponseHeadersStatusContinue
+}
+
+// Destroy implements [gosdk.HttpFilterConfig].
+func (p *javaScriptFilterConfig) Destroy() {}
+
+// Scheduled implements gosdk.HttpFilter.
+func (p *javaScriptFilter) Scheduled(gosdk.EnvoyHttpFilter, uint64) {}
+
+// Destroy implements [gosdk.HttpFilter].
+func (p *javaScriptFilter) Destroy() {}
+
+// RequestBody implements [gosdk.HttpFilter].
+func (p *javaScriptFilter) RequestBody(gosdk.EnvoyHttpFilter, bool) gosdk.RequestBodyStatus {
+	return gosdk.RequestBodyStatusContinue
+}
+
+// ResponseBody implements [gosdk.HttpFilter].
+func (p *javaScriptFilter) ResponseBody(gosdk.EnvoyHttpFilter, bool) gosdk.ResponseBodyStatus {
+	return gosdk.ResponseBodyStatusContinue
+}

go/javascript_test.go

@@ -0,0 +1,134 @@
+package main
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/envoyproxy/dynamic-modules-examples/go/gosdk"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_newJavaScriptFilterConfig(t *testing.T) {
+	f := newJavaScriptFilterConfig(`
+function OnConfigure () {}
+function OnRequestHeaders(ctx) {}
+function OnResponseHeaders(ctx) {}
+`)
+	require.NotNil(t, f)
+}
+
+func Test_newJavasScriptVM(t *testing.T) {
+	for _, tc := range []struct {
+		name   string
+		script string
+		expOut string
+		expErr string
+	}{
+		{
+			name:   "valid script with all functions",
+			expOut: `OnConfigure called`,
+			script: `
+function OnConfigure () {
+  console.log("OnConfigure called");
+}
+function OnRequestHeaders(ctx) {
+  console.log("OnRequestHeader called");
+}
+function OnResponseHeaders(ctx) {
+  console.log("OnResponseHeader called");
+}
+`,
+		},
+		{
+			name: "invalid script with missing functions",
+			script: `
+function OnConfigure () {
+  console.log("OnConfigure called");
+}
+`,
+			expErr: `failed to get OnRequestHeaders function`,
+		},
+		{
+			name:   "invalid script",
+			script: `invalid`,
+			expErr: `failed to run script: ReferenceError: invalid is not defined at <eval>:1:1(0)`,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			logout := &bytes.Buffer{}
+			_, err := newJavaScriptVM(tc.script, logout)
+			if tc.expErr == "" {
+				require.Equal(t, tc.expOut, logout.String())
+				require.NoError(t, err)
+			} else {
+				require.ErrorContains(t, err, tc.expErr)
+			}
+		})
+	}
+}
+
+func Test_javaScriptFilter_RequestHeaders(t *testing.T) {
+	logout := &bytes.Buffer{}
+	vm, err := newJavaScriptVM(
+		`function OnConfigure () {}
+function OnRequestHeaders(ctx) {
+  ctx.setRequestHeader("x-hello", "world");
+  let reqId = ctx.getRequestHeader("x-request-id");
+  console.log("Request ID: ", reqId);
+}
+function OnResponseHeaders(ctx) {}`, logout)
+	require.NoError(t, err)
+
+	f := &javaScriptFilter{vm: vm, requestHeaders: map[string]string{
+		"x-request-id": "12345",
+	}}
+	called := false
+	m := &mockEnvoyHttpFilter{
+		getRequestHeaders: func() map[string][]string { return map[string][]string{"x-request-id": {"12345"}} },
+		setRequestHeader: func(key string, value []byte) bool {
+			require.Equal(t, "x-hello", key)
+			require.Equal(t, "world", string(value))
+			called = true
+			return true
+		},
+	}
+
+	status := f.RequestHeaders(m, false)
+	require.Equal(t, gosdk.RequestHeadersStatusContinue, status)
+	require.True(t, called)
+
+	require.Contains(t, logout.String(), "Request ID: 12345")
+}
+
+func Test_javaScriptFilter_ResponseHeaders(t *testing.T) {
+	logout := &bytes.Buffer{}
+	vm, err := newJavaScriptVM(
+		`function OnConfigure () {}
+function OnRequestHeaders(ctx) {}
+function OnResponseHeaders(ctx) {
+  ctx.setResponseHeader("x-hello", "world");
+  let status = ctx.getResponseHeader(":status");
+  console.log("Response status: ", status);
+}`, logout)
+	require.NoError(t, err)
+
+	f := &javaScriptFilter{vm: vm, responseHeaders: map[string]string{
+		":status": "200",
+	}}
+	called := false
+	m := &mockEnvoyHttpFilter{
+		getResponseHeaders: func() map[string][]string { return map[string][]string{":status": {"200"}} },
+		setResponseHeader: func(key string, value []byte) bool {
+			require.Equal(t, "x-hello", key)
+			require.Equal(t, "world", string(value))
+			called = true
+			return true
+		},
+	}
+
+	status := f.ResponseHeaders(m, false)
+	require.Equal(t, gosdk.ResponseHeadersStatusContinue, status)
+	require.True(t, called)
+
+	require.Contains(t, logout.String(), "Response status: 200")
+}