POST version of GetValidators and GetValidatorBalances (#13199)

* POST versions of GetValidators and GetValidatorBalances

* post statuses

* balances test

* group params

* test error cases

Author: rkapka

beacon-chain/rpc/eth/beacon/handlers_validator.go

@@ -1,7 +1,9 @@
 package beacon
 
 import (
+	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"strconv"
 	"strings"
@@ -49,7 +51,32 @@ func (s *Server) GetValidators(w http.ResponseWriter, r *http.Request) {
 	}
 	isFinalized := s.FinalizationFetcher.IsFinalized(ctx, blockRoot)
 
-	rawIds := r.URL.Query()["id"]
+	var req GetValidatorsRequest
+	if r.Method == http.MethodPost {
+		err = json.NewDecoder(r.Body).Decode(&req)
+		switch {
+		case err == io.EOF:
+			http2.HandleError(w, "No data submitted", http.StatusBadRequest)
+			return
+		case err != nil:
+			http2.HandleError(w, "Could not decode request body: "+err.Error(), http.StatusBadRequest)
+			return
+		}
+	}
+
+	var statuses []string
+	var rawIds []string
+	if r.Method == http.MethodGet {
+		rawIds = r.URL.Query()["id"]
+		statuses = r.URL.Query()["status"]
+	} else {
+		rawIds = req.Ids
+		statuses = req.Statuses
+	}
+	for i, ss := range statuses {
+		statuses[i] = strings.ToLower(ss)
+	}
+
 	ids, ok := decodeIds(w, st, rawIds, true /* ignore unknown */)
 	if !ok {
 		return
@@ -72,11 +99,6 @@ func (s *Server) GetValidators(w http.ResponseWriter, r *http.Request) {
 	epoch := slots.ToEpoch(st.Slot())
 	allBalances := st.Balances()
 
-	statuses := r.URL.Query()["status"]
-	for i, ss := range statuses {
-		statuses[i] = strings.ToLower(ss)
-	}
-
 	// Exit early if no matching validators were found or we don't want to further filter validators by status.
 	if len(readOnlyVals) == 0 || len(statuses) == 0 {
 		containers := make([]*ValidatorContainer, len(readOnlyVals))
@@ -234,7 +256,21 @@ func (bs *Server) GetValidatorBalances(w http.ResponseWriter, r *http.Request) {
 	}
 	isFinalized := bs.FinalizationFetcher.IsFinalized(ctx, blockRoot)
 
-	rawIds := r.URL.Query()["id"]
+	var rawIds []string
+	if r.Method == http.MethodGet {
+		rawIds = r.URL.Query()["id"]
+	} else {
+		err = json.NewDecoder(r.Body).Decode(&rawIds)
+		switch {
+		case err == io.EOF:
+			http2.HandleError(w, "No data submitted", http.StatusBadRequest)
+			return
+		case err != nil:
+			http2.HandleError(w, "Could not decode request body: "+err.Error(), http.StatusBadRequest)
+			return
+		}
+	}
+
 	ids, ok := decodeIds(w, st, rawIds, true /* ignore unknown */)
 	if !ok {
 		return