Extract shared VM lifecycle helpers into firecracker-vm.ts

src/snapshot.ts

@@ -1,45 +1,22 @@
-import { spawn, type ChildProcess } from "node:child_process";
-import { existsSync, mkdirSync } from "node:fs";
+import { type ChildProcess } from "node:child_process";
+import { existsSync, mkdirSync, copyFileSync } from "node:fs";
 import { join } from "node:path";
 import { CONFIG } from "./config.js";
 import * as api from "./firecracker-api.js";
-import {
-  ensureBridge,
-  ensureNat,
-  createTap,
-  deleteTap,
-  macFromOctet,
-} from "./network.js";
-import {
-  ensureBaseImage,
-  ensureSshKeypair,
-  injectSshKey,
-} from "./rootfs.js";
+import { deleteTap } from "./network.js";
+import { ensureBaseImage, ensureSshKeypair, injectSshKey } from "./rootfs.js";
 import { waitForSsh } from "./ssh.js";
-import { copyFileSync } from "node:fs";
+import {
+  setupNetwork,
+  spawnFirecracker,
+  bootVM,
+  killFirecracker,
+} from "./firecracker-vm.js";
 
 function log(msg: string) {
   process.stderr.write(`[snapshot] ${msg}\n`);
 }
 
-function waitForSocket(socketPath: string): Promise<void> {
-  return new Promise((resolve, reject) => {
-    const deadline = Date.now() + 5_000;
-    const check = () => {
-      if (existsSync(socketPath)) {
-        setTimeout(resolve, 200);
-        return;
-      }
-      if (Date.now() > deadline) {
-        reject(new Error("Firecracker socket did not appear"));
-        return;
-      }
-      setTimeout(check, 50);
-    };
-    check();
-  });
-}
-
 export function snapshotExists(): boolean {
   return (
     existsSync(CONFIG.snapshot.statePath) &&
@@ -61,47 +38,21 @@ export async function createSnapshot() {
   injectSshKey(snap.rootfsPath);
 
   log("Setting up network...");
-  ensureBridge();
-  ensureNat();
-  deleteTap(snap.tapDevice); // clean stale tap from previous run
-  createTap(snap.tapDevice);
+  setupNetwork(snap.tapDevice);
 
   let proc: ChildProcess | null = null;
 
   try {
     log("Booting VM for snapshot...");
-    proc = spawn(CONFIG.firecrackerBin, ["--api-sock", socketPath], {
-      stdio: "pipe",
-      detached: false,
+    proc = await spawnFirecracker(socketPath);
+    await bootVM({
+      socketPath,
+      rootfsPath: snap.rootfsPath,
+      tapDevice: snap.tapDevice,
+      ip: snap.ip,
+      octet: snap.octet,
     });
 
-    await waitForSocket(socketPath);
-
-    const bootArgs = [
-      "console=ttyS0",
-      "reboot=k",
-      "panic=1",
-      "pci=off",
-      "root=/dev/vda",
-      "rw",
-      `ip=${snap.ip}::${CONFIG.bridge.gateway}:${CONFIG.bridge.netmask}::eth0:off`,
-    ].join(" ");
-
-    await api.putBootSource(socketPath, CONFIG.kernelPath, bootArgs);
-    await api.putDrive(socketPath, "rootfs", snap.rootfsPath);
-    await api.putNetworkInterface(
-      socketPath,
-      "eth0",
-      snap.tapDevice,
-      macFromOctet(snap.octet)
-    );
-    await api.putMachineConfig(
-      socketPath,
-      CONFIG.vm.vcpuCount,
-      CONFIG.vm.memSizeMib
-    );
-    await api.startInstance(socketPath);
-
     log("Waiting for SSH...");
     await waitForSsh(snap.ip);
 
@@ -116,13 +67,7 @@ export async function createSnapshot() {
     log(`  Memory: ${snap.memPath}`);
     log(`  Rootfs: ${snap.rootfsPath}`);
   } finally {
-    if (proc && !proc.killed) {
-      proc.kill("SIGKILL");
-    }
-    try {
-      const { unlinkSync } = await import("node:fs");
-      unlinkSync(socketPath);
-    } catch {}
+    await killFirecracker(proc, socketPath, "SIGKILL");
     deleteTap(snap.tapDevice);
   }
 }