feat: use FallbackProvider in the DTL

.changeset/eleven-moles-pull.md

@@ -0,0 +1,6 @@
+---
+'@eth-optimism/core-utils': patch
+'@eth-optimism/data-transport-layer': patch
+---
+
+Add fallback provider support to DTL using helper function in core-utils

packages/core-utils/package.json

@@ -47,6 +47,7 @@
   },
   "dependencies": {
     "@ethersproject/abstract-provider": "^5.4.1",
+    "@ethersproject/providers": "^5.4.5",
     "ethers": "^5.4.5",
     "lodash": "^4.17.21"
   }

packages/core-utils/src/index.ts

@@ -6,3 +6,4 @@ export * from './events'
 export * from './batches'
 export * from './bcfg'
 export * from './fees'
+export * from './provider'

packages/core-utils/src/provider.ts

@@ -0,0 +1,40 @@
+/**
+ * Provider Utilities
+ */
+
+import { ethers } from 'ethers'
+import { Provider } from '@ethersproject/providers'
+
+// Copied from @ethersproject/providers since it is not
+// currently exported
+export interface FallbackProviderConfig {
+  // The Provider
+  provider: Provider
+  // The priority to favour this Provider; higher values are used first
+  priority?: number
+  // Timeout before also triggering the next provider; this does not stop
+  // this provider and if its result comes back before a quorum is reached
+  // it will be incorporated into the vote
+  // - lower values will cause more network traffic but may result in a
+  //   faster retult.
+  stallTimeout?: number
+  // How much this provider contributes to the quorum; sometimes a specific
+  // provider may be more reliable or trustworthy than others, but usually
+  // this should be left as the default
+  weight?: number
+}
+
+export const FallbackProvider = (config: string | FallbackProviderConfig[]) => {
+  const configs = []
+  if (typeof config === 'string') {
+    const urls = config.split(',')
+    for (const [i, url] of urls.entries()) {
+      configs.push({
+        priority: i,
+        provider: new ethers.providers.StaticJsonRpcProvider(url),
+      })
+    }
+    return new ethers.providers.FallbackProvider(configs)
+  }
+  return new ethers.providers.FallbackProvider(config)
+}

packages/data-transport-layer/src/services/l1-ingestion/service.ts

@@ -1,7 +1,7 @@
 /* Imports: External */
-import { fromHexString } from '@eth-optimism/core-utils'
+import { fromHexString, FallbackProvider } from '@eth-optimism/core-utils'
 import { BaseService, Metrics } from '@eth-optimism/common-ts'
-import { StaticJsonRpcProvider } from '@ethersproject/providers'
+import { StaticJsonRpcProvider, BaseProvider } from '@ethersproject/providers'
 import { LevelUp } from 'levelup'
 import { ethers, constants } from 'ethers'
 import { Gauge, Counter } from 'prom-client'
@@ -80,7 +80,7 @@ const optionSettings = {
   },
   l1RpcProvider: {
     validate: (val: any) => {
-      return validators.isUrl(val) || validators.isJsonRpcProvider(val)
+      return validators.isString(val) || validators.isJsonRpcProvider(val)
     },
   },
   l2ChainId: {
@@ -98,7 +98,7 @@ export class L1IngestionService extends BaseService<L1IngestionServiceOptions> {
   private state: {
     db: TransportDB
     contracts: OptimismContracts
-    l1RpcProvider: StaticJsonRpcProvider
+    l1RpcProvider: BaseProvider
     startingL1BlockNumber: number
   } = {} as any
 
@@ -107,10 +107,11 @@ export class L1IngestionService extends BaseService<L1IngestionServiceOptions> {
 
     this.l1IngestionMetrics = registerMetrics(this.metrics)
 
-    this.state.l1RpcProvider =
-      typeof this.options.l1RpcProvider === 'string'
-        ? new StaticJsonRpcProvider(this.options.l1RpcProvider)
-        : this.options.l1RpcProvider
+    if (typeof this.options.l1RpcProvider === 'string') {
+      this.state.l1RpcProvider = FallbackProvider(this.options.l1RpcProvider)
+    } else {
+      this.state.l1RpcProvider = this.options.l1RpcProvider
+    }
 
     this.logger.info('Using AddressManager', {
       addressManager: this.options.addressManager,

packages/data-transport-layer/src/types/event-handler-types.ts

@@ -1,4 +1,4 @@
-import { JsonRpcProvider } from '@ethersproject/providers'
+import { BaseProvider } from '@ethersproject/providers'
 import { BigNumber, Event } from 'ethers'
 
 import { TransportDB } from '../db/transport-db'
@@ -15,7 +15,7 @@ export type TypedEthersEvent<T> = Event & {
 
 export type GetExtraDataHandler<TEventArgs, TExtraData> = (
   event?: TypedEthersEvent<TEventArgs>,
-  l1RpcProvider?: JsonRpcProvider
+  l1RpcProvider?: BaseProvider
 ) => Promise<TExtraData>
 
 export type ParseEventHandler<TEventArgs, TExtraData, TParsedEvent> = (

packages/data-transport-layer/src/utils/contracts.ts

@@ -1,12 +1,12 @@
 /* Imports: External */
 import { constants, Contract, Signer } from 'ethers'
-import { JsonRpcProvider } from '@ethersproject/providers'
+import { BaseProvider } from '@ethersproject/providers'
 import { getContractInterface } from '@eth-optimism/contracts'
 
 export const loadContract = (
   name: string,
   address: string,
-  provider: JsonRpcProvider
+  provider: BaseProvider
 ): Contract => {
   return new Contract(address, getContractInterface(name) as any, provider)
 }
@@ -15,7 +15,7 @@ export const loadProxyFromManager = async (
   name: string,
   proxy: string,
   Lib_AddressManager: Contract,
-  provider: JsonRpcProvider
+  provider: BaseProvider
 ): Promise<Contract> => {
   const address = await Lib_AddressManager.getAddress(proxy)
 
@@ -36,7 +36,7 @@ export interface OptimismContracts {
 }
 
 export const loadOptimismContracts = async (
-  l1RpcProvider: JsonRpcProvider,
+  l1RpcProvider: BaseProvider,
   addressManagerAddress: string,
   signer?: Signer
 ): Promise<OptimismContracts> => {

yarn.lock

@@ -922,6 +922,31 @@
     bech32 "1.1.4"
     ws "7.4.6"
 
+"@ethersproject/providers@^5.4.5":
+  version "5.4.5"
+  resolved "https://registry.yarnpkg.com/@ethersproject/providers/-/providers-5.4.5.tgz#eb2ea2a743a8115f79604a8157233a3a2c832928"
+  integrity sha512-1GkrvkiAw3Fj28cwi1Sqm8ED1RtERtpdXmRfwIBGmqBSN5MoeRUHuwHPppMtbPayPgpFcvD7/Gdc9doO5fGYgw==
+  dependencies:
+    "@ethersproject/abstract-provider" "^5.4.0"
+    "@ethersproject/abstract-signer" "^5.4.0"
+    "@ethersproject/address" "^5.4.0"
+    "@ethersproject/basex" "^5.4.0"
+    "@ethersproject/bignumber" "^5.4.0"
+    "@ethersproject/bytes" "^5.4.0"
+    "@ethersproject/constants" "^5.4.0"
+    "@ethersproject/hash" "^5.4.0"
+    "@ethersproject/logger" "^5.4.0"
+    "@ethersproject/networks" "^5.4.0"
+    "@ethersproject/properties" "^5.4.0"
+    "@ethersproject/random" "^5.4.0"
+    "@ethersproject/rlp" "^5.4.0"
+    "@ethersproject/sha2" "^5.4.0"
+    "@ethersproject/strings" "^5.4.0"
+    "@ethersproject/transactions" "^5.4.0"
+    "@ethersproject/web" "^5.4.0"
+    bech32 "1.1.4"
+    ws "7.4.6"
+
 "@ethersproject/random@5.4.0", "@ethersproject/random@^5.0.0", "@ethersproject/random@^5.4.0":
   version "5.4.0"
   resolved "https://registry.yarnpkg.com/@ethersproject/random/-/random-5.4.0.tgz#9cdde60e160d024be39cc16f8de3b9ce39191e16"