From 3ee103818e4a3123fbaf0b18171a0e54c3d838e6 Mon Sep 17 00:00:00 2001
From: Matt <52470716+matt-raffel-kiva@users.noreply.github.com>
Date: Mon, 18 Apr 2022 11:18:14 -0600
Subject: [PATCH] adding basic uptime stats (#59)

* adding basic uptime stats

Signed-off-by: Matt Raffel <mattr@kiva.org>

* adding basic uptime stats

Signed-off-by: Matt Raffel <mattr@kiva.org>
---
 src/app/app.controller.ts          | 13 +++++++++++++
 src/app/app.service.ts             | 16 ++++++++++++++++
 src/app/dtos/service.report.dto.ts | 12 ++++++++++++
 3 files changed, 41 insertions(+)
 create mode 100644 src/app/dtos/service.report.dto.ts

diff --git a/src/app/app.controller.ts b/src/app/app.controller.ts
index 0256bd7..19d6ad5 100644
--- a/src/app/app.controller.ts
+++ b/src/app/app.controller.ts
@@ -1,6 +1,8 @@
 import { Get, Controller } from '@nestjs/common';
 import { HttpConstants } from 'protocol-common/http-context/http.constants';
 import { DisableAutoLogging } from 'protocol-common/disable.auto.logging.decorator';
+import { AppService } from './app.service';
+import { ServiceReportDto } from './dtos/service.report.dto';
 
 /**
  * Base route is just for various health check endpoints
@@ -9,6 +11,9 @@ import { DisableAutoLogging } from 'protocol-common/disable.auto.logging.decorat
 @Controller()
 export class AppController {
 
+    constructor(private readonly service: AppService) {
+    }
+
     @Get()
     base(): string {
         return process.env.SERVICE_NAME;
@@ -23,4 +28,12 @@ export class AppController {
     healthz(): string {
         return HttpConstants.HEALTHZ_RESPONSE;
     }
+
+    /**
+     * For the uptime statistics report (see Uptime feature brief)
+     */
+    @Get('stats')
+    async generateStatsReport() : Promise<ServiceReportDto> {
+        return await this.service.generateStatsReport();
+    }
 }
diff --git a/src/app/app.service.ts b/src/app/app.service.ts
index 22b5641..35d6075 100644
--- a/src/app/app.service.ts
+++ b/src/app/app.service.ts
@@ -7,6 +7,7 @@ import { traceware } from 'protocol-common/tracer';
 import rateLimit from 'express-rate-limit';
 import swaggerUi from 'swagger-ui-express';
 import swaggerDocument from '../docs/swagger.json';
+import { ServiceReportDto } from './dtos/service.report.dto';
 
 /**
  * Sets up the gateway to handle external traffic, eg cors, rate-limiting, etc
@@ -14,6 +15,8 @@ import swaggerDocument from '../docs/swagger.json';
 @Injectable()
 export class AppService {
 
+    private static startedAt: Date;
+
     /**
      * Sets up app in a way that can be used by main.ts and e2e tests
      */
@@ -38,6 +41,8 @@ export class AppService {
 
         app.use(traceware('gateway'));
 
+        AppService.startedAt = new Date();
+
         // Default is 100 requests per minute
         app.use(rateLimit({
             windowMs: process.env.RATE_LIMIT_WINDOW_MS,
@@ -47,4 +52,15 @@ export class AppService {
         // Load swagger docs and display
         app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument));
     };
+
+    public async generateStatsReport(): Promise<ServiceReportDto> {
+        Logger.info('stats report generated');
+        const report: ServiceReportDto = new ServiceReportDto();
+        report.serviceName = process.env.SERVICE_NAME;
+        report.startedAt = AppService.startedAt.toDateString();
+        report.currentTime = new Date().toDateString();
+        report.versions = ['none'];
+
+        return Promise.resolve(report);
+    }
 }
diff --git a/src/app/dtos/service.report.dto.ts b/src/app/dtos/service.report.dto.ts
new file mode 100644
index 0000000..95c52ae
--- /dev/null
+++ b/src/app/dtos/service.report.dto.ts
@@ -0,0 +1,12 @@
+import { IsArray, IsString } from 'class-validator';
+
+/**
+ * Please note: this structure is expected to be used across all services
+ * which report statistics
+ */
+export class ServiceReportDto {
+    @IsString() serviceName: string;
+    @IsString() startedAt: string;
+    @IsString() currentTime: string;
+    @IsArray() versions: string[];
+}