Add Mev Blocker kickbacks alert (#81)

This PR adds a test that monitors for MEV Blocker kickbacks, and
generates an alert if a large enough kickback is received. This is a
follow-up PR on PR #79

---------

Co-authored-by: Felix Henneke <felix.henneke@protonmail.com>

src/constants.py

@@ -25,8 +25,14 @@
 # cap parameter, per CIP-20, measured in ETH
 CAP_PARAMETER = 0.01
 
-# requests
+# threshold parameter to generate an alert when receiving kickbacks
+KICKBACKS_ALERT_THRESHOLD = 0.03
+
+# relevant addresses
 SETTLEMENT_CONTRACT_ADDRESS = "0x9008D19f58AAbD9eD0D60971565AA8510560ab41"
+MEV_BLOCKER_KICKBACKS_ADDRESS = "0xCe91228789B57DEb45e66Ca10Ff648385fE7093b"
+
+# requests
 REQUEST_TIMEOUT = 5
 SUCCESS_CODE = 200
 FAIL_CODE = 404

src/daemon.py

@@ -24,6 +24,9 @@
 from src.monitoring_tests.cost_coverage_per_solver_test import (
     CostCoveragePerSolverTest,
 )
+from src.monitoring_tests.mev_blocker_kickbacks_test import (
+    MEVBlockerRefundsMonitoringTest,
+)
 from src.constants import SLEEP_TIME_IN_SEC
 
 
@@ -40,6 +43,7 @@ def main() -> None:
         PartialFillFeeQuoteTest(),
         PartialFillCostCoverageTest(),
         CostCoveragePerSolverTest(),
+        MEVBlockerRefundsMonitoringTest(),
     ]
 
     start_block: Optional[int] = None

src/monitoring_tests/mev_blocker_kickbacks_test.py

@@ -0,0 +1,50 @@
+"""
+Checks whether there were any kickbacks received after each settlement.
+It generates an alert when kickbacks due to a specific settlement are
+more than KICKBACKS_ALERT_THRESHOLD
+"""
+# pylint: disable=logging-fstring-interpolation
+from src.monitoring_tests.base_test import BaseTest
+from src.apis.web3api import Web3API
+from src.constants import (
+    MEV_BLOCKER_KICKBACKS_ADDRESS,
+    KICKBACKS_ALERT_THRESHOLD,
+)
+
+
+class MEVBlockerRefundsMonitoringTest(BaseTest):
+    """
+    This test checks whether there was any MEV Blocker kicback, and
+    generates a log/alert if this is the case.
+    """
+
+    def __init__(self) -> None:
+        super().__init__()
+        self.web3_api = Web3API()
+
+    def run(self, tx_hash: str) -> bool:
+        """
+        Wrapper function for the whole test. Checks if kickback is more than
+        KICKBACK_ETH_THRESHOLD, in which case it generates an alert.
+        """
+        block_number = self.web3_api.get_tx_block_number(tx_hash)
+        if block_number is None:
+            return False
+
+        total_eth_kickbacks = self.web3_api.get_eth_transfers_by_block_range(
+            block_number, block_number, MEV_BLOCKER_KICKBACKS_ADDRESS
+        )
+        if total_eth_kickbacks is None:
+            return False
+        log_output = "\t".join(
+            [
+                "MEV Blocker kickbacks test:",
+                f"Tx Hash: {tx_hash}",
+                f"Kickback: {total_eth_kickbacks:.5f}ETH",
+            ]
+        )
+        if total_eth_kickbacks >= KICKBACKS_ALERT_THRESHOLD:
+            self.alert(log_output)
+        else:
+            self.logger.info(log_output)
+        return True