Allow empty relayer response

src/validators/relayer.py

@@ -2,7 +2,7 @@
 
 import aiohttp
 from aiohttp import ClientTimeout
-from eth_typing import BLSSignature
+from eth_typing import BLSSignature, HexStr
 from eth_utils import add_0x_prefix
 from web3 import Web3
 
@@ -13,17 +13,31 @@
 # pylint:disable-next=too-few-public-methods
 class BaseRelayerClient(abc.ABC):
     @abc.abstractmethod
-    async def get_validators(self, start_index: int, count: int) -> RelayerValidatorsResponse:
+    async def get_validators(
+        self, validators_start_index: int, validators_batch_size: int, validators_total: int
+    ) -> RelayerValidatorsResponse:
+        """
+        :param validators_start_index: - validator index for the first validator in a batch.
+         Relayer should increment this index for each validator except the first one
+        :param validators_batch_size: - number of validators in a batch. Relayer is expected
+         to return `validators_batch_size` validators at most
+        :param validators_total: - total number of validators supplied by vault assets.
+         Should be more than or equal to `validators_batch_size`.
+         Relayer may use `validators_total` to create larger portions of validators in background.
+        """
         raise NotImplementedError()
 
 
 # pylint:disable-next=too-few-public-methods
 class RelayerClient(BaseRelayerClient):
-    async def get_validators(self, start_index: int, count: int) -> RelayerValidatorsResponse:
+    async def get_validators(
+        self, validators_start_index: int, validators_batch_size: int, validators_total: int
+    ) -> RelayerValidatorsResponse:
         jsn = {
             'vault': settings.vault,
-            'validator_index': start_index,
-            'validators_count': count,
+            'validators_start_index': validators_start_index,
+            'validators_batch_size': validators_batch_size,
+            'validators_total': validators_total,
         }
         async with aiohttp.ClientSession(
             timeout=ClientTimeout(settings.relayer_timeout)
@@ -40,11 +54,12 @@ async def get_validators(self, start_index: int, count: int) -> RelayerValidator
                         Web3.to_bytes(hexstr=add_0x_prefix(v['exit_signature']))
                     ),
                 )
-                for v in resp_json['validators']
+                for v in resp_json.get('validators') or []
             ]
+            validators_manager_signature = add_0x_prefix(
+                resp_json.get('validators_manager_signature') or HexStr('0x')
+            )
             return RelayerValidatorsResponse(
                 validators=validators,
-                validators_manager_signature=add_0x_prefix(
-                    resp_json['validators_manager_signature']
-                ),
+                validators_manager_signature=validators_manager_signature,
             )

src/validators/tasks.py

@@ -125,15 +125,15 @@ async def process_validators(
     # get latest config
     protocol_config = await get_protocol_config()
 
-    validators_count = min(protocol_config.validators_approval_batch_limit, validators_count)
+    validators_batch_size = min(protocol_config.validators_approval_batch_limit, validators_count)
     validators_manager_signature: HexStr | None = None
     validators: Sequence[Validator]
 
     if settings.validators_registration_mode == ValidatorsRegistrationMode.AUTO:
         validators = await get_validators_from_deposit_data(
             keystore=keystore,
             deposit_data=cast(DepositData, deposit_data),
-            count=validators_count,
+            count=validators_batch_size,
         )
         if not validators:
             if not settings.disable_deposit_data_warnings:
@@ -144,10 +144,15 @@ async def process_validators(
                 )
             return None
     else:
-        start_validator_index = await get_start_validator_index()
+        validators_start_index = await get_validators_start_index()
         relayer = cast(RelayerClient, relayer)
-        validators_response = await relayer.get_validators(start_validator_index, validators_count)
+        validators_response = await relayer.get_validators(
+            validators_start_index, validators_batch_size, validators_count
+        )
         validators = validators_response.validators
+        if not validators:
+            logger.info('Waiting for relayer validators')
+            return None
         validators_manager_signature = validators_response.validators_manager_signature
 
     if not await check_gas_price(high_priority=True):
@@ -254,8 +259,8 @@ async def create_approval_request(
     """Generate validator registration request data"""
 
     # get next validator index for exit signature
-    start_validator_index = await get_start_validator_index()
-    logger.debug('Next validator index for exit signature: %d', start_validator_index)
+    validators_start_index = await get_validators_start_index()
+    logger.debug('Next validator index for exit signature: %d', validators_start_index)
 
     proof, proof_flags = None, None
 
@@ -265,7 +270,7 @@ async def create_approval_request(
 
     # get exit signature shards
     request = ApprovalRequest(
-        validator_index=start_validator_index,
+        validator_index=validators_start_index,
         vault_address=settings.vault,
         validators_root=Web3.to_hex(registry_root),
         public_keys=[],
@@ -279,7 +284,7 @@ async def create_approval_request(
         validators_manager_signature=validators_manager_signature,
     )
 
-    for validator_index, validator in enumerate(validators, start_validator_index):
+    for validator_index, validator in enumerate(validators, validators_start_index):
         if isinstance(validator, RelayerValidator):
             exit_signature = validator.exit_signature
         else:
@@ -307,12 +312,12 @@ async def create_approval_request(
     return request
 
 
-async def get_start_validator_index():
+async def get_validators_start_index():
     latest_public_keys = await get_latest_network_validator_public_keys()
-    start_validator_index = NetworkValidatorCrud().get_next_validator_index(
+    validators_start_index = NetworkValidatorCrud().get_next_validator_index(
         list(latest_public_keys)
     )
-    return start_validator_index
+    return validators_start_index
 
 
 async def load_genesis_validators() -> None: