refactor: Add healthz service for health check API endpoint

packages/server/core/src/services/healthz/healthz.class.ts

@@ -0,0 +1,29 @@
+import { ServiceMethods } from '@feathersjs/feathers'
+import { Application } from '../../declarations'
+
+export type HealthzServiceMethods = Pick<ServiceMethods<any>, 'get'>
+
+class HealthzService implements HealthzServiceMethods {
+  app: Application
+
+  constructor(app: Application) {
+    this.app = app
+  }
+
+  async get(): Promise<{ status: string; timestamp: string }> {
+    return {
+      status: 'OK',
+      timestamp: new Date().toISOString(),
+    }
+  }
+}
+
+export const healthz = (app: Application): void => {
+  app.use('/healthz', new HealthzService(app))
+}
+
+declare module '../../declarations' {
+  interface ServiceTypes {
+    '/healthz': HealthzService
+  }
+}

packages/server/core/src/services/index.ts

@@ -15,6 +15,7 @@ import { pluginState } from './state/plugin-state-service'
 import { pluginCommand } from './commands/plugin-command-service'
 import { presigner } from './presigner/presigner-service'
 import { agentChannel } from './agentChannels/agentChannels'
+import { healthz } from './healthz/healthz.class'
 
 // For more information about this file see https://dove.feathersjs.com/guides/cli/application.html#configure-functions
 import type { Application } from '../declarations'
@@ -43,6 +44,7 @@ export const services = async (app: Application): Promise<void> => {
   app.configure(pluginCommand)
   app.configure(presigner)
   app.configure(agentChannel)
+  app.configure(healthz)
 
   // Wait for a tick to handle race condition
   // TODO: handle this race condition better