SSZ web api for decoding input data (#2473)

* first pass ssz server for decoding deposit input data

* fix decoding

* revert viz change on helper

* add image target

* use /api prefix, add deployment for cluster

* fix lint

k8s/beacon-chain/ssz-server.yaml

@@ -0,0 +1,70 @@
+kind: Deployment
+apiVersion: apps/v1
+metadata: 
+  name: ssz-server
+  namespace: beacon-chain
+  labels:
+    app: beacon-chain
+    component: ssz-server
+    version: v1
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: beacon-chain
+      component: ssz-server
+      version: v1
+  template:
+    metadata:
+      labels:
+        app: beacon-chain
+        component: ssz-server
+        version: v1
+    spec:
+      priorityClassName: production-priority
+      containers:
+      - name: site
+        image: gcr.io/prysmaticlabs/prysm/ssz-server:latest
+        livenessProbe:
+          httpGet:
+            path: /healthz
+            port: 4000 
+        resources:
+          requests:
+            cpu: "100m"
+        ports: 
+        - containerPort: 4000
+          name: http
+---
+apiVersion: autoscaling/v2beta1
+kind: HorizontalPodAutoscaler
+metadata:
+  name: ssz-server
+  namespace: beacon-chain
+spec:
+  scaleTargetRef:
+    apiVersion: extensions/v1beta1
+    kind: Deployment
+    name: ssz-server
+  minReplicas: 2
+  maxReplicas: 10
+  metrics:
+  - type: Resource
+    resource:
+      name: cpu
+      targetAverageUtilization: 80
+---
+kind: Service
+apiVersion: v1
+metadata: 
+  name: ssz-server
+  namespace: beacon-chain
+spec:
+  selector:
+    app: beacon-chain
+    component: ssz-server
+  ports:
+  - port: 4000
+    targetPort: 4000
+    name: http
+  type: ClusterIP

k8s/beacon-chain/testnet-site.yaml

@@ -100,6 +100,16 @@ spec:
   gateways:
   - prylabs-wildcard-gateway
   http:
+  - match:
+    - uri:
+        prefix: /ssz
+    rewrite:
+      uri: /api
+    route:
+    - destination:
+        port:
+          number: 4000
+        host: ssz-server.beacon-chain.svc.cluster.local
   - match:
     - uri:
         prefix: /

tools/ssz-server/BUILD.bazel

@@ -0,0 +1,48 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+load("@io_bazel_rules_docker//go:image.bzl", "go_image")
+load("@io_bazel_rules_docker//container:container.bzl", "container_push")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["main.go"],
+    importpath = "github.com/prysmaticlabs/prysm/tools/ssz-server",
+    visibility = ["//visibility:private"],
+    deps = [
+        "//proto/beacon/p2p/v1:go_default_library",
+        "//shared/ssz:go_default_library",
+    ],
+)
+
+go_binary(
+    name = "ssz-server",
+    embed = [":go_default_library"],
+    visibility = ["//visibility:public"],
+)
+
+go_image(
+    name = "image",
+    srcs = ["main.go"],
+    importpath = "github.com/prysmaticlabs/prysm/tools/ssz-server",
+    visibility = ["//visibility:private"],
+    static = "on",
+    tags = ["manual"],
+    goarch = "amd64",
+    goos = "linux",
+    deps = [
+        "//proto/beacon/p2p/v1:go_default_library",
+        "//shared/ssz:go_default_library",
+    ],
+    race = "off",
+    pure = "on",
+)
+
+container_push(
+    name = "push_image",
+    format = "Docker",
+    image = ":image",
+    registry = "gcr.io",
+    repository = "prysmaticlabs/prysm/ssz-server",
+    tag = "latest",
+    tags = ["manual"],
+    visibility = ["//visibility:private"],
+)

tools/ssz-server/main.go

@@ -0,0 +1,96 @@
+// This binary is a simple ssz deserializer REST API endpoint for the testnet
+// frontend to decode the deposit data for the user.
+// This should be removed after https://github.com/prysmaticlabs/prysm-testnet-site/issues/37
+// is resolved.
+package main
+
+import (
+	"bytes"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+
+	pb "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
+	"github.com/prysmaticlabs/prysm/shared/ssz"
+)
+
+func main() {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/healthz", healthz)
+	mux.HandleFunc("/api/decodeDepositData", decodeDepositData)
+
+	log.Println("Starting on port 4000")
+	if err := http.ListenAndServe(":4000", mux); err != nil {
+		log.Fatalf("Failed to start server %v", err)
+	}
+}
+
+func healthz(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusOK)
+}
+
+type deserializationRequest struct {
+	Data string `json:"data"`
+}
+
+func decodeDepositData(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		return
+	}
+
+	data, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		log.Printf("Failed to read request body: %v\n", err)
+		return
+	}
+
+	requestData := &deserializationRequest{}
+	if err := json.Unmarshal(data, requestData); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		log.Printf("Unable to unmarshal JSON: %v\n", err)
+		return
+	}
+
+	if len(requestData.Data) < 2 {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	encodedData, err := hex.DecodeString(requestData.Data[2:])
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		_, err = fmt.Fprintf(w, "Failed to decode hex string")
+		if err != nil {
+			log.Printf("Failed to write data to client: %v\n", err)
+		}
+		return
+	}
+
+	di := &pb.DepositInput{}
+
+	if err := ssz.Decode(bytes.NewReader(encodedData), di); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		_, err := fmt.Fprintf(w, "Failed to decode SSZ data: %v", err)
+		if err != nil {
+			log.Printf("Failed to write data to client: %v\n", err)
+		}
+		return
+	}
+
+	b, err := json.Marshal(di)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		log.Printf("Failed to marshal deposit data: %v\n", err)
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	_, err = w.Write(b)
+	if err != nil {
+		log.Printf("Failed to write data to client: %v\n", err)
+	}
+}