validatorapi: supporting getValidators with post (#2849)

Implemented POST get validators endpoint.

category: feature
ticket: #2840

core/validatorapi/router.go

@@ -323,12 +323,24 @@ func wrapTrace(endpoint string, handler http.HandlerFunc) http.Handler {
 	return otelhttp.NewHandler(handler, "core/validatorapi."+endpoint)
 }
 
-// getValidator returns a handler function for the get validators by pubkey or index endpoint.
+// getValidators returns a handler function for the get validators by pubkey or index endpoint.
 func getValidators(p eth2client.ValidatorsProvider) handlerFunc {
-	return func(ctx context.Context, params map[string]string, query url.Values, _ contentType, _ []byte) (any, http.Header, error) {
+	return func(ctx context.Context, params map[string]string, query url.Values, _ contentType, body []byte) (any, http.Header, error) {
 		stateID := params["state_id"]
 
-		resp, err := getValidatorsByID(ctx, p, stateID, getValidatorIDs(query)...)
+		// TODO: support 'status' param when go-eth2-client supports it
+		// https://github.com/ObolNetwork/charon/issues/2846
+		ids := getValidatorIDs(query)
+		if len(ids) == 0 && len(body) > 0 {
+			postIDs, err := getValidatorIDsFromJSON(body)
+			if err != nil {
+				return nil, nil, errors.Wrap(err, "getting validator ids from request body")
+			}
+
+			ids = postIDs
+		}
+
+		resp, err := getValidatorsByID(ctx, p, stateID, ids...)
 		if err != nil {
 			return nil, nil, err
 		} else if len(resp) == 0 {
@@ -1249,10 +1261,15 @@ func (w proxyResponseWriter) WriteHeader(statusCode int) {
 	w.writeFlusher.WriteHeader(statusCode)
 }
 
-// getValidatorIDs returns validator IDs as "id" query parameters (supporting csv values).
+// getValidatorIDs returns validator IDs as "id" array query parameters.
 func getValidatorIDs(query url.Values) []string {
+	return getQueryArrayParameter(query, "id")
+}
+
+// getQueryArrayParameter returns all array values passed as query parameter (supporting csv values).
+func getQueryArrayParameter(query url.Values, param string) []string {
 	var resp []string
-	for _, csv := range query["id"] {
+	for _, csv := range query[param] {
 		for _, id := range strings.Split(csv, ",") {
 			resp = append(resp, strings.TrimSpace(id))
 		}
@@ -1261,6 +1278,19 @@ func getValidatorIDs(query url.Values) []string {
 	return resp
 }
 
+// getValidatorIDsFromJSON returns validator IDs as "id" field of json payload.
+func getValidatorIDsFromJSON(b []byte) ([]string, error) {
+	requestBody := struct {
+		IDs []string `json:"ids"`
+	}{}
+
+	if err := json.Unmarshal(b, &requestBody); err != nil {
+		return nil, errors.Wrap(err, "failed to parse request body")
+	}
+
+	return requestBody.IDs, nil
+}
+
 // getValidatorsByID returns the validators with ids being either pubkeys or validator indexes.
 func getValidatorsByID(ctx context.Context, p eth2client.ValidatorsProvider, stateID string, ids ...string) ([]v1Validator, error) {
 	flatten := func(kvs map[eth2p0.ValidatorIndex]*eth2v1.Validator) []v1Validator {

core/validatorapi/router_internal_test.go

@@ -320,6 +320,86 @@ func TestRawRouter(t *testing.T) {
 		testRawRouter(t, handler, callback)
 	})
 
+	t.Run("get validators with post", func(t *testing.T) {
+		simpleValidatorsFunc := func(_ context.Context, opts *eth2api.ValidatorsOpts) (*eth2api.Response[map[eth2p0.ValidatorIndex]*eth2v1.Validator], error) { //nolint:golint,unparam
+			res := make(map[eth2p0.ValidatorIndex]*eth2v1.Validator)
+			if len(opts.Indices) == 0 {
+				opts.Indices = []eth2p0.ValidatorIndex{12, 35}
+			}
+
+			for _, index := range opts.Indices {
+				res[index] = &eth2v1.Validator{
+					Index:  index,
+					Status: eth2v1.ValidatorStateActiveOngoing,
+					Validator: &eth2p0.Validator{
+						PublicKey:             testutil.RandomEth2PubKey(t),
+						WithdrawalCredentials: []byte("12345678901234567890123456789012"),
+					},
+				}
+			}
+
+			return wrapResponse(res), nil
+		}
+
+		assertResults := func(t *testing.T, res *http.Response) {
+			t.Helper()
+
+			resp := struct {
+				Data []*eth2v1.Validator `json:"data"`
+			}{}
+			err := json.NewDecoder(res.Body).Decode(&resp)
+			require.NoError(t, err)
+			require.Len(t, resp.Data, 2)
+			require.EqualValues(t, eth2p0.ValidatorIndex(12), resp.Data[0].Index)
+			require.EqualValues(t, eth2p0.ValidatorIndex(35), resp.Data[1].Index)
+		}
+
+		t.Run("via query ids", func(t *testing.T) {
+			handler := testHandler{ValidatorsFunc: simpleValidatorsFunc}
+
+			callback := func(ctx context.Context, baseURL string) {
+				res, err := http.Post(baseURL+"/eth/v1/beacon/states/head/validators?id=12,35", "application/json", bytes.NewReader([]byte{}))
+				require.NoError(t, err)
+				assertResults(t, res)
+			}
+
+			testRawRouter(t, handler, callback)
+		})
+
+		t.Run("via post body", func(t *testing.T) {
+			handler := testHandler{ValidatorsFunc: simpleValidatorsFunc}
+
+			callback := func(ctx context.Context, baseURL string) {
+				b := struct {
+					IDs []string `json:"ids"`
+				}{
+					IDs: []string{"12", "35"},
+				}
+
+				bb, err := json.Marshal(b)
+				require.NoError(t, err)
+
+				res, err := http.Post(baseURL+"/eth/v1/beacon/states/head/validators", "application/json", bytes.NewReader(bb))
+				require.NoError(t, err)
+				assertResults(t, res)
+			}
+
+			testRawRouter(t, handler, callback)
+		})
+
+		t.Run("empty parameters", func(t *testing.T) {
+			handler := testHandler{ValidatorsFunc: simpleValidatorsFunc}
+
+			callback := func(ctx context.Context, baseURL string) {
+				res, err := http.Post(baseURL+"/eth/v1/beacon/states/head/validators", "application/json", bytes.NewReader([]byte{}))
+				require.NoError(t, err)
+				assertResults(t, res)
+			}
+
+			testRawRouter(t, handler, callback)
+		})
+	})
+
 	t.Run("submit bellatrix ssz proposal", func(t *testing.T) {
 		var done atomic.Bool
 		coreBlock := testutil.RandomBellatrixCoreVersionedSignedProposal()