Allow to override JSON RPC error codes (#603)

CONFIGURATION.md

@@ -52,6 +52,7 @@ ORACLE_SHUTDOWN_CONTRACT_ADDRESS | Optional contract address in the side chain a
 ORACLE_SHUTDOWN_CONTRACT_METHOD | Method signature to be used in the side chain to identify the current shutdown status. Method should return boolean. Default value is `isShutdown()`. | `function signature`
 ORACLE_FOREIGN_RPC_BLOCK_POLLING_LIMIT | Max length for the block range used in `eth_getLogs` requests for polling contract events for the Foreign chain. Infinite, if not provided. | `integer`
 ORACLE_HOME_RPC_BLOCK_POLLING_LIMIT | Max length for the block range used in `eth_getLogs` requests for polling contract events for the Home chain. Infinite, if not provided. | `integer`
+ORACLE_JSONRPC_ERROR_CODES | Override default JSON rpc error codes that can trigger RPC fallback to the next URL from the list (or a retry in case of a single RPC URL). Default is `-32603,-32002,-32005`. Should be a comma-separated list of negative integers. | `string`
 
 
 ## Monitor configuration

oracle/src/services/HttpListProvider.js

@@ -4,8 +4,12 @@ const { FALLBACK_RPC_URL_SWITCH_TIMEOUT } = require('../utils/constants')
 
 const { onInjected } = require('./injectedLogger')
 
+const { ORACLE_JSONRPC_ERROR_CODES } = process.env
+
 // From EIP-1474 and Infura documentation
-const JSONRPC_ERROR_CODES = [-32603, -32002, -32005]
+const JSONRPC_ERROR_CODES = ORACLE_JSONRPC_ERROR_CODES
+  ? ORACLE_JSONRPC_ERROR_CODES.split(',').map(s => parseInt(s, 10))
+  : [-32603, -32002, -32005]
 
 const defaultOptions = {
   name: 'main',