feat: besu WatchBlocksV1Endpoint with SocketIO

Primary change(s):
-----------------

1. Adds an async endpoint based on
the new SocketIO integration of the API server. The endpoint streams new
block headers to the clients as they come in through the subscription
mechanism of Web3.

2. The besu connector plugin is now capable of
accepting the WS RPC API host of the backing Besu client/ledger so that
it can instantiate a WebSocket provider for itself which was a
prerequisite of being able to use the Web3 subscriptions functionality
that the async endponit needs to work.

Secondary change(s):
-------------------

1. Updated the supply chain app example and the besu tests to
accomodate the change that the besu connector now needs to use
the web socket RPC API instead of the HTTP one.

Signed-off-by: Peter Somogyvari <peter.somogyvari@accenture.com>

examples/cactus-example-supply-chain-backend/src/main/typescript/infrastructure/supply-chain-app-dummy-infrastructure.ts

@@ -200,12 +200,14 @@ export class SupplyChainAppDummyInfrastructure {
       {
         this._besuAccount = await this.besu.createEthTestAccount(2000000);
         const rpcApiHttpHost = await this.besu.getRpcApiHttpHost();
+        const rpcApiWsHost = await this.besu.getRpcApiWsHost();
 
         const pluginRegistry = new PluginRegistry();
         pluginRegistry.add(keychainPlugin);
         const connector = new PluginLedgerConnectorBesu({
           instanceId: "PluginLedgerConnectorBesu_Contract_Deployment",
           rpcApiHttpHost,
+          rpcApiWsHost,
           logLevel: this.options.logLevel,
           pluginRegistry,
         });

examples/cactus-example-supply-chain-backend/src/main/typescript/supply-chain-app.ts

@@ -147,6 +147,7 @@ export class SupplyChainApp {
 
     this.log.info(`Configuring Cactus Node for Ledger A...`);
     const rpcApiHostA = await this.ledgers.besu.getRpcApiHttpHost();
+    const rpcApiWsHostA = await this.ledgers.besu.getRpcApiWsHost();
     const rpcApiHostB = await this.ledgers.quorum.getRpcApiHttpHost();
 
     const connectionProfile = await this.ledgers.fabric.getConnectionProfileOrg1();
@@ -187,6 +188,7 @@ export class SupplyChainApp {
     const connectorBesu = new PluginLedgerConnectorBesu({
       instanceId: "PluginLedgerConnectorBesu_A",
       rpcApiHttpHost: rpcApiHostA,
+      rpcApiWsHost: rpcApiWsHostA,
       pluginRegistry: registryA,
       logLevel: this.options.logLevel,
     });

packages/cactus-plugin-ledger-connector-besu/package.json

@@ -91,13 +91,17 @@
     "joi": "14.3.1",
     "openapi-types": "7.0.1",
     "prom-client": "13.1.0",
+    "rxjs": "6.6.7",
+    "socket.io-client": "4.0.1",
     "typescript-optional": "2.0.1",
     "web3": "1.2.7",
     "web3-utils": "1.2.7"
   },
   "devDependencies": {
     "@hyperledger/cactus-plugin-keychain-memory": "0.5.0",
     "@hyperledger/cactus-test-tooling": "0.5.0",
-    "@types/express": "4.17.8"
+    "@types/express": "4.17.8",
+    "socket.io": "4.0.1",
+    "web3-eth": "1.2.7"
   }
 }