add inject_encoded_data_to_filter_chain_on_header example (#3071)

plugins/wasm-go/examples/test-foreign-function/main.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
+	"github.com/higress-group/wasm-go/pkg/log"
+	pb "github.com/higress-group/wasm-go/pkg/protos"
+	"github.com/higress-group/wasm-go/pkg/wrapper"
+	"github.com/tidwall/gjson"
+	"google.golang.org/protobuf/proto"
+)
+
+type TestConfig struct {
+}
+
+func main() {}
+
+func init() {
+	wrapper.SetCtx(
+		"test-foreign-function",
+		wrapper.ParseConfig(parseConfig),
+		wrapper.ProcessResponseHeaders(onHttpResponseHeaders),
+	)
+}
+
+func parseConfig(configJson gjson.Result, config *TestConfig) error {
+	return nil
+}
+
+func onHttpResponseHeaders(ctx wrapper.HttpContext, config TestConfig) types.Action {
+	proxywasm.RemoveHttpResponseHeader("content-length")
+	ctx.DontReadResponseBody()
+	d := &pb.InjectEncodedDataToFilterChainArguments{
+		Body:      "hello foreign function\n",
+		Endstream: true,
+	}
+	s, _ := proto.Marshal(d)
+	_, err := proxywasm.CallForeignFunction("inject_encoded_data_to_filter_chain_on_header", s)
+	if err != nil {
+		log.Errorf("call inject_encoded_data_to_filter_chain_on_header failed, error: %+v", err)
+	}
+	return types.ActionContinue
+}