Load testing: synthetic VMs, multiple worker support and Grafana k6 test (#389)

* Load testing: synthetic VMs, multiple worker support and Grafana k6 test

* echoserver: prevent fallthrough when Accept() fails

* Move default local-dev context logic to CreateDevController()

* Synthetic: add a random delay to startup script echoing

test/load/vm-lifecycle.js

@@ -0,0 +1,120 @@
+import {check} from 'k6';
+import http from 'k6/http';
+import {WebSocket} from 'k6/experimental/websockets';
+import crypto from 'k6/crypto';
+import {uuidv4} from 'https://jslib.k6.io/k6-utils/1.6.0/index.js';
+import {expect} from 'https://jslib.k6.io/k6-testing/0.6.1/index.js';
+
+const BASE_URL = __ENV.ORCHARD_BASE_URL || 'http://127.0.0.1:6120/v1';
+const WS_BASE_URL = __ENV.ORCHARD_WS_BASE_URL || BASE_URL.replace(/^http/, 'ws');
+const WS_BYTES = __ENV.WS_BYTES || 64 * 1024;
+
+export const options = {
+    scenarios: {
+        vmLifecycle: {
+            executor: 'ramping-vus',
+            stages: [
+                {duration: '5m', target: 2_000},
+            ],
+        },
+    },
+};
+
+export default async function () {
+    const vmName = `k6-${uuidv4()}`;
+
+    createVM(vmName);
+
+    await portForward(vmName);
+
+    deleteVM(vmName);
+}
+
+function createVM(vmName) {
+    const loremIpsum = `Lorem ipsum
+    dolor sit amet,
+    consectetur adipiscing elit.
+    Fusce at orci nisi.
+    Donec lacinia neque et risus elementum,
+    ut interdum lacus pretium.
+`;
+
+    const body = JSON.stringify({
+        name: vmName,
+        image: 'ghcr.io/cirruslabs/macos-tahoe-base:latest',
+        headless: true,
+        startup_script: {
+            script_content: loremIpsum
+        },
+    });
+
+    const resp = http.post(`${BASE_URL}/vms`, body, {
+        headers: {
+            'Content-Type': 'application/json',
+        },
+    });
+
+    const ok = check(resp, {
+        'VM creation succeeded': (r) => r.status === 200,
+    });
+
+    if (!ok) {
+        console.error(`Failed to create a VM: HTTP ${resp.status}`);
+    }
+}
+
+async function portForward(vmName) {
+    const url = `${WS_BASE_URL}/vms/${vmName}/port-forward?port=22&wait=60`;
+
+    console.debug(`connecting to ${url}`);
+
+    const ws = new WebSocket(url);
+    ws.binaryType = 'arraybuffer';
+
+    const sentBytes = new Uint8Array(crypto.randomBytes(WS_BYTES));
+    let receivedBytes = new Uint8Array();
+
+    const evt = await new Promise((resolve, reject) => {
+        ws.onopen = () => {
+            ws.send(sentBytes);
+        };
+
+        ws.onmessage = (event) => {
+            if (event.data instanceof ArrayBuffer) {
+                const chunk = new Uint8Array(event.data);
+
+                const combined = new Uint8Array(receivedBytes.length + chunk.length);
+                combined.set(receivedBytes);
+                combined.set(chunk, receivedBytes.length);
+                receivedBytes = combined;
+            }
+
+            if (receivedBytes.length >= WS_BYTES) {
+                ws.close();
+            }
+        };
+
+        ws.onerror = (evt) => {
+            reject(new Error(`WebSocket error: ${evt.error}`));
+        };
+
+        ws.onclose = (evt) => {
+            resolve(evt);
+        };
+    });
+
+    expect(evt.code).toBe(1000);
+    expect(receivedBytes).toEqual(sentBytes);
+}
+
+function deleteVM(vmName) {
+    const resp = http.del(`${BASE_URL}/vms/${vmName}`);
+
+    const ok = check(resp, {
+        'VM deletion succeeded': (r) => r.status === 200,
+    });
+
+    if (!ok) {
+        console.error(`Failed to delete a VM: HTTP ${resp.status}`);
+    }
+}