deno: add manage-vm.

2 files changed, 149 insertions, 1 deletions

diff --git a/deno/tools/deno.json b/deno/tools/deno.json
index 355046a..cda933f 100644
--- a/deno/tools/deno.json
+++ b/deno/tools/deno.json
@@ -3,6 +3,7 @@
   "tasks": {
   },
   "imports": {
-    "mustache": "npm:mustache@^4.2.0"
+    "mustache": "npm:mustache@^4.2.0",
+    "yargs": "npm:yargs@^18.0.0"
   }
 }
diff --git a/deno/tools/manage-vm.ts b/deno/tools/manage-vm.ts
new file mode 100644
index 0000000..a1388b1
--- /dev/null
+++ b/deno/tools/manage-vm.ts
@@ -0,0 +1,147 @@
+import os from "node:os"
+import { join } from "@std/path";
+// @ts-types="npm:@types/yargs"
+import yargs from "yargs";
+
+
+type ArchAliasMap = { [name: string]: string[] };
+const arches = {
+  x86_64: ["x86_64", "amd64"],
+  i386: ["i386", "x86", "i686"],
+} as const satisfies ArchAliasMap;
+type Arch = keyof typeof arches;
+type GeneralArch = (typeof arches)[Arch][number];
+
+function normalizeArch(generalName: GeneralArch): Arch {
+  for (const [name, aliases] of Object.entries(
+    arches as ArchAliasMap,
+  )) {
+    if (aliases.includes(generalName)) return name as Arch;
+  }
+  throw Error("Unknown architecture name.");
+}
+
+interface GeneralVmSetup {
+  name?: string[];
+  arch: GeneralArch;
+  disk: string;
+  sshForwardPort: number;
+  kvm?: boolean;
+}
+
+interface VmSetup {
+  arch: Arch;
+  disk: string;
+  sshForwardPort: number;
+  kvm: boolean;
+}
+
+const MY_VMS: GeneralVmSetup[] = [
+  {
+    name: ["hurd", ...arches.i386.map((a) => `hurd-${a}`)],
+    arch: "i386",
+    disk: join(os.homedir(), "vms/hurd-i386.qcow2"),
+    sshForwardPort: 3222,
+  },
+  {
+    name: [...arches.x86_64.map((a) => `hurd-${a}`)],
+    arch: "x86_64",
+    disk: join(os.homedir(), "vms/hurd-x86_64.qcow2"),
+    sshForwardPort: 3223,
+  },
+];
+
+function normalizeVmSetup(generalSetup: GeneralVmSetup): VmSetup {
+  const { arch, disk, sshForwardPort, kvm } = generalSetup;
+  return {
+    arch: normalizeArch(arch),
+    disk,
+    sshForwardPort,
+    kvm: kvm ?? Deno.build.os === "linux",
+  };
+}
+
+function resolveVmSetup(
+  name: string,
+  vms: GeneralVmSetup[],
+): VmSetup | undefined {
+  const setup = vms.find((vm) => vm.name?.includes(name));
+  return setup == null ? undefined : normalizeVmSetup(setup);
+}
+
+const qemuBinPrefix = "qemu-system" as const;
+
+const qemuBinSuffix = {
+  x86_64: "x86_64",
+  i386: "x86_64",
+} as const;
+
+function getQemuBin(arch: Arch): string {
+  return `${qemuBinPrefix}-${qemuBinSuffix[arch]}`;
+}
+
+function getLinuxHostArgs(kvm: boolean): string[] {
+  return kvm ? ["-enable-kvm"] : [];
+}
+
+function getMachineArgs(arch: Arch): string[] {
+  const is64 = arch === "x86_64";
+  const machineArgs = is64 ? ["-machine", "q35"] : [];
+  const memory = is64 ? 8 : 4;
+  return [...machineArgs, "-m", `${memory}G`];
+}
+
+function getNetworkArgs(sshForwardPort: number): string[] {
+  return ["-net", "nic", "-net", `user,hostfwd=tcp::${sshForwardPort}-:22`];
+}
+
+function getDisplayArgs(): string[] {
+  return ["-vga", "vmware"];
+}
+
+function getDiskArgs(disk: string): string[] {
+  return ["-drive", `cache=writeback,file=${disk}`];
+}
+
+function createQemuArgs(setup: VmSetup): string[] {
+  const { arch, disk, sshForwardPort } = setup;
+  return [
+    getQemuBin(arch),
+    ...getLinuxHostArgs(setup.kvm),
+    ...getMachineArgs(arch),
+    ...getDisplayArgs(),
+    ...getNetworkArgs(sshForwardPort),
+    ...getDiskArgs(disk),
+  ];
+}
+
+if (import.meta.main) {
+  await yargs(Deno.args)
+    .scriptName("manage-vm")
+    .command({
+      command: "gen <name>",
+      describe: "generate cli command to run the vm",
+      builder: (builder) => {
+        return builder
+          .positional("name", {
+            describe: "name of the vm to run",
+            type: "string",
+          })
+          .demandOption("name")
+          .strict();
+      },
+      handler: (argv) => {
+        const vm = resolveVmSetup(argv.name, MY_VMS);
+        if (vm == null) {
+          console.error(`No vm called ${argv.name} is found.`);
+          Deno.exit(-1);
+        }
+        const cli = createQemuArgs(vm);
+        console.log(`${cli.join(" ")}`);
+      },
+    })
+    .demandCommand(1, "One command must be specified.")
+    .help()
+    .strict()
+    .parse();
+}