Add lightclient cmd (#3937)

packages/cli/package.json

@@ -56,6 +56,7 @@
     "@chainsafe/blst": "^0.2.4",
     "@chainsafe/discv5": "^0.6.7",
     "@chainsafe/lodestar": "^0.36.0",
+    "@chainsafe/lodestar-light-client": "^0.36.0",
     "@chainsafe/lodestar-api": "^0.36.0",
     "@chainsafe/lodestar-beacon-state-transition": "^0.36.0",
     "@chainsafe/lodestar-config": "^0.36.0",

packages/cli/src/cmds/index.ts

@@ -5,10 +5,12 @@ import {beacon} from "./beacon";
 import {dev} from "./dev";
 import {init} from "./init";
 import {validator} from "./validator";
+import {lightclient} from "./lightclient";
 
 export const cmds: Required<ICliCommand<IGlobalArgs, Record<never, never>>>["subcommands"] = [
   beacon,
   validator,
+  lightclient,
   account,
   init,
   dev,

packages/cli/src/cmds/lightclient/handler.ts

@@ -0,0 +1,32 @@
+import {getClient} from "@chainsafe/lodestar-api";
+import {Lightclient} from "@chainsafe/lodestar-light-client";
+import {fromHexString} from "@chainsafe/ssz";
+import {getBeaconConfigFromArgs} from "../../config/beaconParams";
+import {IGlobalArgs} from "../../options";
+import {getCliLogger, initBLS} from "../../util";
+import {getBeaconPaths} from "../beacon/paths";
+import {ILightClientArgs} from "./options";
+
+export async function lightclientHandler(args: ILightClientArgs & IGlobalArgs): Promise<void> {
+  await initBLS();
+
+  const config = getBeaconConfigFromArgs(args);
+  const beaconPaths = getBeaconPaths(args);
+  const logger = getCliLogger(args, beaconPaths, config);
+  const {beaconApiUrl, checkpointRoot} = args;
+  const api = getClient({baseUrl: beaconApiUrl}, {config});
+  const {data: genesisData} = await api.beacon.getGenesis();
+
+  const client = await Lightclient.initializeFromCheckpointRoot({
+    config,
+    logger,
+    beaconApiUrl,
+    genesisData: {
+      genesisTime: Number(genesisData.genesisTime),
+      genesisValidatorsRoot: genesisData.genesisValidatorsRoot,
+    },
+    checkpointRoot: fromHexString(checkpointRoot),
+  });
+
+  client.start();
+}

packages/cli/src/cmds/lightclient/index.ts

@@ -0,0 +1,17 @@
+import {ICliCommand} from "../../util";
+import {IGlobalArgs} from "../../options";
+import {ILightClientArgs, lightclientOptions} from "./options";
+import {lightclientHandler} from "./handler";
+
+export const lightclient: ICliCommand<ILightClientArgs, IGlobalArgs> = {
+  command: "lightclient",
+  describe: "Run lightclient",
+  examples: [
+    {
+      command: "lightclient --network prater",
+      description: "Run lightclient with prater network",
+    },
+  ],
+  options: lightclientOptions,
+  handler: lightclientHandler,
+};

packages/cli/src/cmds/lightclient/options.ts

@@ -0,0 +1,24 @@
+import {ICliCommandOptions, ILogArgs} from "../../util";
+import {beaconPathsOptions, logOptions} from "../beacon/options";
+import {IBeaconPaths} from "../beacon/paths";
+
+export type ILightClientArgs = ILogArgs & {
+  logFile: IBeaconPaths["logFile"];
+  beaconApiUrl: string;
+  checkpointRoot: string;
+};
+
+export const lightclientOptions: ICliCommandOptions<ILightClientArgs> = {
+  ...logOptions,
+  logFile: beaconPathsOptions.logFile,
+  beaconApiUrl: {
+    description: "Url to a beacon node that support lightclient API",
+    type: "string",
+    require: true,
+  },
+  checkpointRoot: {
+    description: "Checkpoint root hex string to sync the lightclient from, start with 0x",
+    type: "string",
+    require: true,
+  },
+};