add grpc trace id example

Author: yuanchaoa

example/grpc/grpc.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"github.com/deepflowio/deepflow-wasm-go-sdk/sdk"
+	sdkpb "github.com/deepflowio/deepflow-wasm-go-sdk/sdk/pb"
+)
+
+//go:generate mkdir -p pb
+//go:generate bash -c "cd protoc-gen-demo && go build"
+//go:generate protoc --go_out=./pb --demo_out=./pb --plugin=protoc-gen-demo=./protoc-gen-demo/protoc-gen-demo --go-vtproto_out=./pb --go-vtproto_opt=features=unmarshal ./demo.proto
+
+func main() {
+	sdk.SetParser(SomeParser{})
+	sdk.Warn("plugin loaded")
+}
+
+type SomeParser struct {
+}
+
+func (p SomeParser) OnCustomMessage(ctx *sdk.CustomMessageCtx) sdk.Action {
+	return sdk.ActionNext()
+}
+
+func (p SomeParser) OnNatsMessage(message sdkpb.NatsMessage) sdk.Action {
+	return sdk.ActionNext()
+}
+
+func (p SomeParser) CustomMessageHookIn() uint64 {
+	return 0
+}
+
+func (p SomeParser) HookIn() []sdk.HookBitmap {
+	return []sdk.HookBitmap{
+		// 这里的钩子是在 HTTP/HTTP2/gRPC 解析中，目的是增强 HTTP/HTTP2/gRPC 协议解析的能力，
+		// 解析方法和内容由用户自定义，但是日志解析后的协议字段依旧为 HTTP/HTTP2/gRPC.
+		sdk.HOOK_POINT_HTTP_REQ,
+		sdk.HOOK_POINT_HTTP_RESP,
+	}
+}
+
+func (p SomeParser) OnHttpReq(ctx *sdk.HttpReqCtx) sdk.Action {
+	info := &sdk.L7ProtocolInfo{
+		Req:           &sdk.Request{},
+		ProtocolMerge: true,
+		IsEnd:         true,
+		Trace: &sdk.Trace{
+			TraceID: "this-trace-id-from-wasm",
+		},
+	}
+	return sdk.ParseActionAbortWithL7Info([]*sdk.L7ProtocolInfo{info})
+}
+
+func (p SomeParser) OnHttpResp(ctx *sdk.HttpRespCtx) sdk.Action {
+	return sdk.ActionNext()
+}
+
+func (p SomeParser) OnCheckPayload(ctx *sdk.ParseCtx) (uint8, string) {
+	// 这里是协议判断的逻辑， 返回 0 表示失败
+	return 1, "GrpcTraceID"
+}
+
+func (p SomeParser) OnParsePayload(ctx *sdk.ParseCtx) sdk.Action {
+	// 这里是解析协议的逻辑
+	if ctx.L4 != sdk.TCP || ctx.L7 != 1 {
+		return sdk.ActionNext()
+	}
+	return sdk.ActionNext()
+}