HTTP Request Sink Tool (#8689)

* request sink test

* append if not exist

tools/http-request-sink/BUILD.bazel

@@ -0,0 +1,56 @@
+load("@prysm//tools/go:def.bzl", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_test")
+load("@io_bazel_rules_docker//go:image.bzl", "go_image")
+load("@io_bazel_rules_docker//container:container.bzl", "container_bundle")
+load("@io_bazel_rules_docker//contrib:push-all.bzl", "docker_push")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["main.go"],
+    importpath = "github.com/prysmaticlabs/prysm/tools/http-request-sink",
+    visibility = ["//visibility:private"],
+    deps = ["//shared/params:go_default_library"],
+)
+
+go_binary(
+    name = "http-request-sink",
+    embed = [":go_default_library"],
+    visibility = ["//visibility:public"],
+)
+
+go_image(
+    name = "image",
+    base = select({
+        "//tools:base_image_alpine": "//tools:alpine_cc_image",
+        "//tools:base_image_cc": "//tools:cc_image",
+        "//conditions:default": "//tools:cc_image",
+    }),
+    binary = ":http-request-sink",
+    tags = ["manual"],
+    visibility = ["//visibility:private"],
+)
+
+container_bundle(
+    name = "image_bundle",
+    images = {
+        "gcr.io/prysmaticlabs/prysm/http-request-sink:latest": ":image",
+        "gcr.io/prysmaticlabs/prysm/http-request-sink:{DOCKER_TAG}": ":image",
+    },
+    tags = ["manual"],
+)
+
+docker_push(
+    name = "push_images",
+    bundle = ":image_bundle",
+    tags = ["manual"],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["main_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//shared/params:go_default_library",
+        "//shared/testutil/require:go_default_library",
+    ],
+)

tools/http-request-sink/main.go

@@ -0,0 +1,76 @@
+// Package main implements a simple, http-request-sink which writes
+// incoming http request bodies to an append-only text file at a specified directory.
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+
+	"github.com/prysmaticlabs/prysm/shared/params"
+)
+
+func main() {
+	port := flag.Int("port", 8080, "port to listen on")
+	writeDirPath := flag.String("write-dir", "", "directory to write an append-only file")
+	flag.Parse()
+	if *writeDirPath == "" {
+		log.Fatal("Needs a -write-dir path")
+	}
+
+	// If the file doesn't exist, create it, or append to the file.
+	f, err := os.OpenFile(
+		filepath.Join(*writeDirPath, "requests.log"),
+		os.O_APPEND|os.O_CREATE|os.O_RDWR,
+		params.BeaconIoConfig().ReadWritePermissions,
+	)
+	if err != nil {
+		log.Println(err)
+	}
+	defer func() {
+		if err = f.Close(); err != nil {
+			log.Fatal(err)
+		}
+	}()
+
+	http.HandleFunc("/", func(writer http.ResponseWriter, r *http.Request) {
+		reqContent := map[string]interface{}{}
+		if err = parseRequest(r, &reqContent); err != nil {
+			log.Println(err)
+		}
+		log.Printf("Capturing request from %s", r.RemoteAddr)
+		if err = captureRequest(f, reqContent); err != nil {
+			log.Println(err)
+		}
+	})
+	log.Printf("Listening on port %d", *port)
+	log.Fatal(http.ListenAndServe(":"+strconv.Itoa(*port), nil))
+}
+
+func captureRequest(f *os.File, m map[string]interface{}) error {
+	enc, err := json.Marshal(m)
+	if err != nil {
+		return err
+	}
+	_, err = f.WriteString(fmt.Sprintf("%s\n", enc))
+	return err
+}
+
+func parseRequest(req *http.Request, unmarshalStruct interface{}) error {
+	body, err := ioutil.ReadAll(req.Body)
+	if err != nil {
+		return err
+	}
+	if err = req.Body.Close(); err != nil {
+		return err
+	}
+	req.Body = ioutil.NopCloser(bytes.NewBuffer(body))
+	return json.Unmarshal(body, unmarshalStruct)
+}

tools/http-request-sink/main_test.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/shared/params"
+	"github.com/prysmaticlabs/prysm/shared/testutil/require"
+)
+
+type sampleRPCRequest struct {
+	Name      string `json:"name"`
+	ETHMethod string `json:"eth_method"`
+	Address   string `json:"address"`
+}
+
+func Test_parseAndCaptureRequest(t *testing.T) {
+	tmpFile := filepath.Join(os.TempDir(), "faketest.log")
+	t.Cleanup(func() {
+		require.NoError(t, os.RemoveAll(tmpFile))
+	})
+	body := &sampleRPCRequest{
+		Name:      "eth2",
+		ETHMethod: "eth2_produceBlock",
+		Address:   "0x0923920930923",
+	}
+	enc, err := json.Marshal(body)
+	require.NoError(t, err)
+	httpReq, err := http.NewRequest("GET", "/", bytes.NewBuffer(enc))
+	require.NoError(t, err)
+
+	reqContent := map[string]interface{}{}
+	err = parseRequest(httpReq, &reqContent)
+	require.NoError(t, err)
+
+	// If the file doesn't exist, create it, or append to the file.
+	f, err := os.OpenFile(
+		tmpFile,
+		os.O_APPEND|os.O_CREATE|os.O_RDWR,
+		params.BeaconIoConfig().ReadWritePermissions,
+	)
+	require.NoError(t, err)
+
+	err = captureRequest(f, reqContent)
+	require.NoError(t, err)
+	require.NoError(t, f.Close())
+
+	f, err = os.Open(tmpFile)
+	require.NoError(t, err)
+	fileContents, err := ioutil.ReadAll(f)
+	require.NoError(t, err)
+
+	receivedContent := map[string]interface{}{}
+	err = json.Unmarshal(fileContents, &receivedContent)
+	require.NoError(t, err)
+
+	for key, val := range reqContent {
+		receivedVal, ok := receivedContent[key]
+		require.Equal(t, true, ok)
+		require.DeepEqual(t, val, receivedVal)
+	}
+}