Nixos support (#4)

* build nixos

Signed-off-by: Christine Dodrill <me@christine.website>

* does this work lol

Signed-off-by: Christine Dodrill <me@christine.website>

* oops

Signed-off-by: Christine Dodrill <me@christine.website>

* openstack?

Signed-off-by: Christine Dodrill <me@christine.website>

* oops lol

Signed-off-by: Christine Dodrill <me@christine.website>

* write a fake cloud config i guess

Signed-off-by: Christine Dodrill <me@christine.website>

* enable ssh lol

Signed-off-by: Christine Dodrill <me@christine.website>

* openstack is banned

Signed-off-by: Christine Dodrill <me@christine.website>

* lol oops x3

Signed-off-by: Christine Dodrill <me@christine.website>

* enable cloud init

Signed-off-by: Christine Dodrill <me@christine.website>

.gitignore

@@ -0,0 +1 @@
+*.qcow2

main.go

@@ -44,6 +44,16 @@ func main() {
 	rand.Seed(time.Now().Unix())
 	flag.Parse()
 
+	cdir, err := os.UserCacheDir()
+	if err != nil {
+		log.Fatalf("can't find cache dir: %v", err)
+	}
+	cdir = filepath.Join(cdir, "within", "mkvm")
+	os.MkdirAll(filepath.Join(cdir, "nixos"), 0755)
+	os.MkdirAll(filepath.Join(cdir, "qcow2"), 0755)
+	os.MkdirAll(filepath.Join(cdir, "seed"), 0755)
+	vmID := uuid.New().String()
+
 	if *name == "" {
 		commonBladeName, err := getName()
 		if err != nil {
@@ -59,6 +69,18 @@ func main() {
 
 	var resultDistro Distro
 	var found bool
+	qcowPath := filepath.Join(cdir, "nixos", vmID, "nixos.qcow2")
+
+	if *distro == "nixos" {
+		found = true
+		resultDistro = Distro{
+			Name:        "nixos",
+			DownloadURL: "file://" + qcowPath,
+			Sha256Sum:   "<computed after build>",
+			MinSize:     8,
+		}
+	}
+
 	for _, d := range distros {
 		if d.Name == *distro {
 			found = true
@@ -78,7 +100,11 @@ func main() {
 		}
 		os.Exit(1)
 	}
+
 	zvol := filepath.Join(*zvolPrefix, *name)
+	if resultDistro.Name != "nixos" {
+		qcowPath = filepath.Join(cdir, "qcow2", resultDistro.Sha256Sum)
+	}
 
 	macAddress, err := randomMac()
 	if err != nil {
@@ -90,8 +116,6 @@ func main() {
 		log.Fatalf("can't connect to libvirt: %v", err)
 	}
 
-	vmID := uuid.New().String()
-
 	log.Println("plan:")
 	log.Printf("name: %s", *name)
 	log.Printf("zvol: %s (%d GB)", zvol, *zvolSize)
@@ -108,14 +132,13 @@ func main() {
 	fmt.Print("press enter if this looks okay: ")
 	reader.ReadString('\n')
 
-	cdir, err := os.UserCacheDir()
+	if *distro == "nixos" {
-	if err != nil {
+		_, err := mkNixOSImage(*cloudConfig, cdir, vmID)
-		log.Fatalf("can't find cache dir: %v", err)
+		if err != nil {
+			log.Fatal(err)
+		}
 	}
-	cdir = filepath.Join(cdir, "within", "mkvm")
+
-	os.MkdirAll(filepath.Join(cdir, "qcow2"), 0755)
-	os.MkdirAll(filepath.Join(cdir, "seed"), 0755)
-	qcowPath := filepath.Join(cdir, "qcow2", resultDistro.Sha256Sum)
 	_, err = os.Stat(qcowPath)
 	if err != nil {
 		log.Printf("downloading distro image %s to %s", resultDistro.DownloadURL, qcowPath)
@@ -189,9 +212,18 @@ func main() {
 	}
 	fout.Close()
 
-	err = run("cp", *cloudConfig, filepath.Join(dir, "user-data"))
+	if *distro != "nixos" {
-	if err != nil {
+		err = run("cp", *cloudConfig, filepath.Join(dir, "user-data"))
-		log.Fatal(err)
+		if err != nil {
+			log.Fatal(err)
+		}
+	} else {
+		fout, err := os.Create(filepath.Join(dir, "user-data"))
+		if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Fprintln(fout, "#cloud-config")
+		fout.Close()
 	}
 
 	isoPath := filepath.Join(cdir, "seed", fmt.Sprintf("%s-%s.iso", *name, vmID))

nixos.go

@@ -0,0 +1,13 @@
+package main
+
+import "path/filepath"
+
+func mkNixOSImage(configFname, cacheDir, vmID string) (string, error) {
+	outputFname := filepath.Join(cacheDir, "nixos", vmID)
+	err := run("nix-shell", "-p", "nixos-generators", "--run", "nixos-generate -f qcow -o "+outputFname+" -c "+configFname)
+	if err != nil {
+		return "", err
+	}
+
+	return outputFname, nil
+}

var/xe-base.nix

@@ -0,0 +1,28 @@
+{ config, pkgs, modulesPath, ... }:
+
+{
+  imports = [ (modulesPath + "/profiles/qemu-guest.nix") ];
+
+  boot.initrd.availableKernelModules =
+    [ "ata_piix" "uhci_hcd" "virtio_pci" "sr_mod" "virtio_blk" ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ ];
+  boot.extraModulePackages = [ ];
+
+  users.users.xe = {
+    isNormalUser = true;
+    initialPassword = "hunter2";
+    extraGroups = [ "wheel" ];
+    openssh.authorizedKeys.keys = [
+      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPg9gYKVglnO2HQodSJt4z4mNrUSUiyJQ7b+J798bwD9"
+    ];
+  };
+
+  services.openssh.enable = true;
+
+  security.sudo.wheelNeedsPassword = false;
+  services.cloud-init = {
+    enable = true;
+    ext4.enable = true;
+  };
+}