Add Health API endpoint

Author: XavierGeerinck

src/implementation/Client/DaprClient.ts

@@ -21,6 +21,9 @@ import HTTPClient from './HTTPClient/HTTPClient';
 
 import CommunicationProtocolEnum from '../../enum/CommunicationProtocol.enum';
 import { DaprClientOptions } from '../../types/DaprClientOptions';
+import HTTPClientHealth from './HTTPClient/health';
+import IClientHealth from '../../interfaces/Client/IClientHealth';
+import GRPCClientHealth from './GRPCClient/health';
 
 export default class DaprClient {
   readonly daprHost: string;
@@ -34,6 +37,7 @@ export default class DaprClient {
   readonly binding: IClientBinding;
   readonly invoker: IClientInvoker;
   readonly secret: IClientSecret;
+  readonly health: IClientHealth;
 
   constructor(
     daprHost: string
@@ -64,6 +68,7 @@ export default class DaprClient {
         this.binding = new GRPCClientBinding(client);
         this.invoker = new GRPCClientInvoker(client);
         this.secret = new GRPCClientSecret(client);
+        this.health = new GRPCClientHealth(client);
         break;
       }
       case CommunicationProtocolEnum.HTTP:
@@ -76,6 +81,7 @@ export default class DaprClient {
         this.binding = new HTTPClientBinding(client);
         this.invoker = new HTTPClientInvoker(client);
         this.secret = new HTTPClientSecret(client);
+        this.health = new HTTPClientHealth(client);
         break;
       }
     }

src/implementation/Client/GRPCClient/health.ts

@@ -0,0 +1,15 @@
+import GRPCClient from './GRPCClient';
+import IClientHealth from '../../../interfaces/Client/IClientHealth';
+
+// https://docs.dapr.io/reference/api/health_api/
+export default class GRPCClientHealth implements IClientHealth {
+  client: GRPCClient;
+
+  constructor(client: GRPCClient) {
+    this.client = client;
+  }
+
+  async isHealthy(): Promise<boolean> {
+    return true;
+  }
+}

src/implementation/Client/HTTPClient/health.ts

@@ -0,0 +1,27 @@
+import HTTPClient from './HTTPClient';
+import IClientHealth from '../../../interfaces/Client/IClientHealth';
+
+// https://docs.dapr.io/reference/api/health_api/
+export default class HTTPClientHealth implements IClientHealth {
+  client: HTTPClient;
+
+  constructor(client: HTTPClient) {
+    this.client = client;
+  }
+
+  // Send an event to an external system
+  async isHealthy(): Promise<boolean> {
+    try {
+      const result = await this.client.execute(`/healthz`, {
+        method: 'GET',
+        headers: {
+          'Content-Type': 'application/json',
+        }
+      });
+
+      return true;
+    } catch (e) {
+      return false;
+    }
+  }
+}