Add GET /v2/device/metrics endpoint

Closes: #1710
Change-type: minor
Signed-off-by: Christina Ying Wang <[email protected]>

docs/API.md

@@ -1298,3 +1298,33 @@ Show journal logs until the given `until` timestamp, formats are described here:
 
 An example project using this endpoint can be found
 [in this repository](https://github.com/balena-io-playground/device-cloud-logging).
+
+#### Device metrics
+
+> **Introduced in supervisor v16.11.0**
+
+Get current device metrics.
+
+From an app container:
+
+```bash
+$ curl "$BALENA_SUPERVISOR_ADDRESS/v2/device/metrics?apikey=$BALENA_SUPERVISOR_API_KEY"
+```
+
+Response:
+```json
+{
+	"status": "success",
+	"metrics": {
+		"cpu_usage": 0.5,
+		"memory_usage": 1024,
+		"memory_total": 2048,
+		"storage_usage": 1024,
+		"storage_total": 2048,
+		"storage_block_device": "sda",
+		"cpu_temp": 50,
+		"cpu_id": "1234567890",
+		"is_undervolted": false
+	}
+}
+```

src/device-api/actions.ts

@@ -27,6 +27,7 @@ import {
 	BadRequestError,
 } from '../lib/errors';
 import { withLock } from '../lib/update-lock';
+import * as systemInfo from '../lib/system-info';
 
 /**
  * Run an array of healthchecks, outputting whether all passed or not
@@ -445,3 +446,15 @@ export const patchHostConfig = async (conf: unknown, force: boolean) => {
 	}
 	await hostConfig.patch(parsedConf, force);
 };
+
+/**
+ * Get device metrics and checks
+ * Used by:
+ * 	- GET /v2/device/metrics
+ */
+export const getMetrics = async () => {
+	return {
+		...(await systemInfo.getSystemMetrics()),
+		...(await systemInfo.getSystemChecks()),
+	};
+};

src/device-api/v2.ts

@@ -575,3 +575,15 @@ router.post('/v2/journal-logs', (req, res) => {
 		res.end();
 	});
 });
+
+router.get('/v2/device/metrics', async (_req, res, next) => {
+	try {
+		const metrics = await actions.getMetrics();
+		return res.json({
+			status: 'success',
+			metrics,
+		});
+	} catch (e) {
+		next(e);
+	}
+});

test/integration/device-api/actions.spec.ts

@@ -1338,3 +1338,18 @@ describe('patches host config', () => {
 		expect(hostConfigPatch).to.have.been.calledWith(conf, true);
 	});
 });
+
+describe('gets metrics', () => {
+	it('gets system metrics and checks', async () => {
+		const metrics = await actions.getMetrics();
+		expect(metrics).to.have.property('cpu_usage');
+		expect(metrics).to.have.property('memory_usage');
+		expect(metrics).to.have.property('memory_total');
+		expect(metrics).to.have.property('storage_usage');
+		expect(metrics).to.have.property('storage_total');
+		expect(metrics).to.have.property('storage_block_device');
+		expect(metrics).to.have.property('cpu_temp');
+		expect(metrics).to.have.property('cpu_id');
+		expect(metrics).to.have.property('is_undervolted');
+	});
+});

test/integration/device-api/v2.spec.ts

@@ -639,4 +639,47 @@ describe('device-api/v2', () => {
 				.expect(503);
 		});
 	});
+
+	describe('GET /v2/device/metrics', () => {
+		// Actions are tested elsewhere so we can stub the dependency here
+		let getMetricsStub: SinonStub;
+		beforeEach(() => {
+			getMetricsStub = stub(actions, 'getMetrics').resolves();
+		});
+		afterEach(async () => {
+			getMetricsStub.restore();
+			// Remove all scoped API keys between tests
+			await db.models('apiSecret').whereNot({ appId: 0 }).del();
+		});
+
+		it('responds with 200 if metrics are returned', async () => {
+			const metrics = {
+				cpu_usage: 0.5,
+				memory_usage: 1024,
+				memory_total: 2048,
+				storage_usage: 1024,
+				storage_total: 2048,
+				storage_block_device: 'sda',
+				cpu_temp: 50,
+				cpu_id: '1234567890',
+				is_undervolted: false,
+			};
+			getMetricsStub.resolves(metrics);
+			await request(api)
+				.get('/v2/device/metrics')
+				.set('Authorization', `Bearer ${await apiKeys.getGlobalApiKey()}`)
+				.expect(200, {
+					status: 'success',
+					metrics,
+				});
+		});
+
+		it('responds with 503 if there is an error getting metrics', async () => {
+			getMetricsStub.throws(new Error());
+			await request(api)
+				.get('/v2/device/metrics')
+				.set('Authorization', `Bearer ${await apiKeys.getGlobalApiKey()}`)
+				.expect(503);
+		});
+	});
 });