middleware: add wasm basic (#1747)

* middleware: add wasm basic

Signed-off-by: Loong <loong.dai@intel.com>

* Update middleware/http/wasm/basic/basic.go

* Update middleware/http/wasm/basic/basic.go

Co-authored-by: Taction <zchao9100@gmail.com>
Co-authored-by: Yaron Schneider <schneider.yaron@live.com>
Co-authored-by: Bernd Verst <4535280+berndverst@users.noreply.github.com>

go.mod

@@ -321,6 +321,7 @@ require (
 	github.com/spf13/cast v1.3.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/stretchr/objx v0.3.0 // indirect
+	github.com/tetratelabs/wazero v0.0.0-20220425003459-ad61d9a6ff43
 	github.com/tidwall/match v1.0.3 // indirect
 	github.com/tjfoc/gmsm v1.3.2 // indirect
 	github.com/tklauser/go-sysconf v0.3.6 // indirect

go.sum

@@ -1798,6 +1798,8 @@ github.com/syndtr/gocapability v0.0.0-20200815063812-42c35b437635/go.mod h1:hkRG
 github.com/tchap/go-patricia v2.2.6+incompatible/go.mod h1:bmLyhP68RS6kStMGxByiQ23RP/odRBOTVjwp2cDyi6I=
 github.com/tebeka/strftime v0.1.3/go.mod h1:7wJm3dZlpr4l/oVK0t1HYIc4rMzQ2XJlOMIUJUJH6XQ=
 github.com/testcontainers/testcontainers-go v0.9.0/go.mod h1:b22BFXhRbg4PJmeMVWh6ftqjyZHgiIl3w274e9r3C2E=
+github.com/tetratelabs/wazero v0.0.0-20220425003459-ad61d9a6ff43 h1:o/PS34ksCpw72GtxUKad1jDMPsgGn6zVRG0BFIOUrsU=
+github.com/tetratelabs/wazero v0.0.0-20220425003459-ad61d9a6ff43/go.mod h1:Y4X/zO4sC2dJjZG9GDYNRbJGogfqFYJY/BbyKlOxXGI=
 github.com/tevid/gohamcrest v1.1.1/go.mod h1:3UvtWlqm8j5JbwYZh80D/PVBt0mJ1eJiYgZMibh0H/k=
 github.com/tidwall/gjson v1.2.1/go.mod h1:c/nTNbUr0E0OrXEhq1pwa8iEgc2DOt4ZZqAt1HtCkPA=
 github.com/tidwall/gjson v1.8.1 h1:8j5EE9Hrh3l9Od1OIEDAb7IpezNA20UdRngNAj5N0WU=

middleware/http/wasm/basic/basic.go

@@ -0,0 +1,139 @@
+package basic
+
+import (
+	"encoding/json"
+	"log"
+	"os"
+	"path/filepath"
+
+	"github.com/pkg/errors"
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/wasi"
+	"github.com/valyala/fasthttp"
+
+	"github.com/dapr/components-contrib/middleware"
+	"github.com/dapr/kit/logger"
+)
+
+type middlewareMetadata struct {
+	Path    string `json:"path"`
+	Runtime string `json:"runtime"`
+}
+
+// Middleware is an wasm basic middleware.
+type Middleware struct {
+	logger logger.Logger
+}
+
+// NewMiddleware returns a new wasm basic middleware.
+func NewMiddleware(logger logger.Logger) *Middleware {
+	return &Middleware{logger: logger}
+}
+
+// GetHandler returns the HTTP handler provided by wasm basic middleware.
+func (m *Middleware) GetHandler(metadata middleware.Metadata) (func(h fasthttp.RequestHandler) fasthttp.RequestHandler, error) {
+	var (
+		meta *middlewareMetadata
+		err  error
+	)
+	meta, err = m.getNativeMetadata(metadata)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to parse wasm basic metadata")
+	}
+	if meta.Runtime != "wazero" {
+		return nil, errors.Wrap(err, "only support wazero runtime")
+	}
+	path, err := filepath.Abs(meta.Path)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to find wasm basic file")
+	}
+	return func(h fasthttp.RequestHandler) fasthttp.RequestHandler {
+		return func(ctx *fasthttp.RequestCtx) {
+			// Create a new WebAssembly Runtime.
+			r := wazero.NewRuntime()
+
+			// TinyGo needs WASI to implement functions such as panic.
+			wm, err := wasi.InstantiateSnapshotPreview1(ctx, r)
+			if err != nil {
+				log.Fatal(err)
+			}
+			defer wm.Close(ctx)
+
+			wasmByte, err := os.ReadFile(path)
+			if err != nil {
+				log.Fatalf("wasm file %v", err)
+			}
+
+			mod, err := r.InstantiateModuleFromCode(ctx, wasmByte)
+			if err != nil {
+				log.Fatal(err)
+			}
+			defer mod.Close(ctx)
+
+			// These are undocumented, but exported. See tinygo-org/tinygo#2788
+			malloc := mod.ExportedFunction("malloc")
+			free := mod.ExportedFunction("free")
+
+			uriFunc := mod.ExportedFunction("run")
+			if uriFunc == nil {
+				log.Fatal(err)
+			}
+
+			uri := ctx.RequestURI()
+			uriLength := uint64(len(uri))
+
+			// Instead of an arbitrary memory offset, use TinyGo's allocator. Notice
+			// there is nothing string-specific in this allocation function. The same
+			// function could be used to pass binary serialized data to Wasm.
+			results, err := malloc.Call(ctx, uriLength)
+			if err != nil {
+				log.Fatal(err)
+			}
+			uriPtr := results[0]
+			// This pointer is managed by TinyGo, but TinyGo is unaware of external usage.
+			// So, we have to free it when finished
+			defer free.Call(ctx, uriPtr)
+
+			// The pointer is a linear memory offset, which is where we write the value.
+			if !mod.Memory().Write(ctx, uint32(uriPtr), uri) {
+				log.Fatalf("Memory.Write(%d, %d) out of range of memory size %d",
+					uriPtr, uriLength, mod.Memory().Size(ctx))
+			}
+
+			// Now, we can call "uriFunc", which reads the string we wrote to memory!
+			ptrSize, err := uriFunc.Call(ctx, uriPtr, uriLength)
+			// if err != nil {
+			if err != nil {
+				log.Fatal(err)
+			}
+
+			// Note: This pointer is still owned by TinyGo, so don't try to free it!
+			retPtr := uint32(ptrSize[0] >> 32)
+			retSize := uint32(ptrSize[0])
+			// The pointer is a linear memory offset, which is where we write the name.
+			if bytes, ok := mod.Memory().Read(ctx, retPtr, retSize); !ok {
+				log.Fatalf("Memory.Read(%d, %d) out of range of memory size %d",
+					retPtr, retSize, mod.Memory().Size(ctx))
+			} else {
+				ctx.Request.SetRequestURIBytes(bytes)
+			}
+
+			h(ctx)
+		}
+	}, nil
+}
+
+func (m *Middleware) getNativeMetadata(metadata middleware.Metadata) (*middlewareMetadata, error) {
+	b, err := json.Marshal(metadata.Properties)
+	if err != nil {
+		return nil, err
+	}
+
+	var data middlewareMetadata
+	err = json.Unmarshal(b, &data)
+	if err != nil {
+		return nil, err
+	}
+
+	return &data, nil
+}

middleware/http/wasm/basic/basic_test.go

@@ -0,0 +1,34 @@
+package basic
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/valyala/fasthttp"
+
+	"github.com/dapr/components-contrib/middleware"
+	"github.com/dapr/kit/logger"
+)
+
+type testHandler struct{}
+
+func (t *testHandler) handle(ctx *fasthttp.RequestCtx) {
+}
+
+func TestGetHandler(t *testing.T) {
+	meta := middleware.Metadata{Properties: map[string]string{
+		"path":    "./hello.wasm",
+		"runtime": "wazero",
+	}}
+	log := logger.NewLogger("wasm.basic.test")
+	handler, err := NewMiddleware(log).GetHandler(meta)
+	assert.Nil(t, err)
+
+	var ctx fasthttp.RequestCtx
+	ctx.Request.SetRequestURI("/v1.0/hi")
+
+	th := &testHandler{}
+	handler(th.handle)(&ctx)
+
+	assert.Equal(t, "/v1.0/hello", string(ctx.RequestURI()))
+}