kvm2: domain and volume XML, metadata element and NoCloud seed builders

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-16 16:57:30 +00:00
parent 95768281be
commit 1f10a51f82
9 changed files with 1473 additions and 2 deletions
@@ -0,0 +1,264 @@
+package kvm2
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/textproto"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/kdomanski/iso9660"
+)
+
+// readSeed builds a seed and returns its files by name plus the label.
+func readSeed(t *testing.T, name, userData, vendorData string) (map[string]string, string) {
+	t.Helper()
+	var buf bytes.Buffer
+	if err := buildSeedISO(name, userData, vendorData, &buf); err != nil {
+		t.Fatalf("buildSeedISO: %v", err)
+	}
+	img, err := iso9660.OpenImage(bytes.NewReader(buf.Bytes()))
+	if err != nil {
+		t.Fatalf("OpenImage: %v", err)
+	}
+	root, err := img.RootDir()
+	if err != nil {
+		t.Fatalf("RootDir: %v", err)
+	}
+	children, err := root.GetChildren()
+	if err != nil {
+		t.Fatalf("GetChildren: %v", err)
+	}
+	files := make(map[string]string, len(children))
+	for _, c := range children {
+		if c.IsDir() {
+			t.Errorf("unexpected directory %q in seed", c.Name())
+			continue
+		}
+		data, err := io.ReadAll(c.Reader())
+		if err != nil {
+			t.Fatalf("reading %s: %v", c.Name(), err)
+		}
+		files[c.Name()] = string(data)
+	}
+	label, err := img.Label()
+	if err != nil {
+		t.Fatalf("Label: %v", err)
+	}
+	return files, label
+}
+
+func TestSeedISO_filesAndLabel(t *testing.T) {
+	t.Parallel()
+	userData := "#cloud-config\npackages: [squid]\n"
+	vendorData := "#!/bin/sh\necho hi\n"
+	files, label := readSeed(t, "proxy-abc", userData, vendorData)
+	if label != seedLabel {
+		t.Errorf("label = %q, want %q", label, seedLabel)
+	}
+	want := map[string]string{
+		"user-data":   userData,
+		"meta-data":   "instance-id: proxy-abc\nlocal-hostname: proxy-abc\n",
+		"vendor-data": vendorData,
+	}
+	if len(files) != len(want) {
+		t.Errorf("seed has %d files %v, want exactly %d", len(files), keys(files), len(want))
+	}
+	for name, content := range want {
+		if got, ok := files[name]; !ok {
+			t.Errorf("seed lacks %s", name)
+		} else if got != content {
+			t.Errorf("%s = %q, want %q", name, got, content)
+		}
+	}
+}
+
+func keys(m map[string]string) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	return out
+}
+
+func TestSeedISO_userDataByteForByte(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name     string
+		userData string
+	}{
+		{name: "mime multipart with CRLF", userData: "MIME-Version: 1.0\r\nContent-Type: multipart/mixed; boundary=\"b\"\r\n\r\n--b\r\nContent-Type: text/cloud-config\r\n\r\n#cloud-config\r\npackages: [squid]\r\n--b--\r\n"},
+		{name: "jinja header", userData: "## template: jinja\n#cloud-config\nhostname: {{ v1.local_hostname }}\n"},
+		{name: "no trailing newline", userData: "#cloud-config\nruncmd:\n  - echo done"},
+		{name: "bytes above 0x7f", userData: "#cloud-config\nwrite_files:\n  - content: \"caf\xc3\xa9 \xff\xfe\x80\"\n"},
+		{name: "empty", userData: ""},
+		{name: "trailing whitespace preserved", userData: "#!/bin/sh\necho x \n\n\n"},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			files, _ := readSeed(t, "proxy-abc", tc.userData, "")
+			if got := files["user-data"]; got != tc.userData {
+				t.Errorf("user-data changed:\n got %q\nwant %q", got, tc.userData)
+			}
+		})
+	}
+}
+
+// Not parallel: it changes TMPDIR for the process.
+func TestSeedISO_tempDirRemoved(t *testing.T) {
+	tmp := t.TempDir()
+	t.Setenv("TMPDIR", tmp)
+	if got := os.TempDir(); got != tmp {
+		t.Fatalf("os.TempDir() = %q, want %q", got, tmp)
+	}
+	var buf bytes.Buffer
+	if err := buildSeedISO("proxy-abc", "#cloud-config\n", guestAgentScript, &buf); err != nil {
+		t.Fatalf("buildSeedISO: %v", err)
+	}
+	if buf.Len() == 0 {
+		t.Fatal("seed ISO is empty")
+	}
+	entries, err := os.ReadDir(tmp)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(entries) != 0 {
+		names := make([]string, 0, len(entries))
+		for _, e := range entries {
+			names = append(names, e.Name())
+		}
+		t.Errorf("staging left behind in TMPDIR: %v", names)
+	}
+}
+
+func TestSeedISO_emptyVendorDataStillHasFile(t *testing.T) {
+	t.Parallel()
+	files, _ := readSeed(t, "proxy-abc", "#cloud-config\n", "")
+	got, ok := files["vendor-data"]
+	if !ok {
+		t.Fatalf("seed lacks vendor-data; files: %v", keys(files))
+	}
+	if got != "" {
+		t.Errorf("vendor-data = %q, want empty", got)
+	}
+}
+
+func TestSeedISO_rejectsEmptyName(t *testing.T) {
+	t.Parallel()
+	var buf bytes.Buffer
+	if err := buildSeedISO("", "#cloud-config\n", "", &buf); err == nil {
+		t.Fatal("buildSeedISO with empty name succeeded")
+	}
+	if buf.Len() != 0 {
+		t.Errorf("wrote %d bytes alongside the error", buf.Len())
+	}
+}
+
+func TestVendorData_isShellScriptNotCloudConfig(t *testing.T) {
+	t.Parallel()
+	got, err := buildVendorData("", true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.HasPrefix(got, "#!/bin/sh\n") {
+		t.Errorf("vendor-data starts with %q, want #!/bin/sh", firstLine(got))
+	}
+	if strings.HasPrefix(got, "#cloud-config") {
+		t.Error("vendor-data is a cloud-config; cloud-init would merge it away")
+	}
+	for _, want := range []string{"qemu-guest-agent", "set -e", "apt-get", "dnf", "yum", "zypper", "apk", "systemctl enable --now qemu-guest-agent", "rc-update", "installGuestAgent: false", "DEBIAN_FRONTEND=noninteractive"} {
+		if !strings.Contains(got, want) {
+			t.Errorf("script lacks %q", want)
+		}
+	}
+	if strings.Contains(got, "MIME-Version") {
+		t.Error("script alone should not be wrapped in a multipart")
+	}
+}
+
+func firstLine(s string) string {
+	line, _, _ := strings.Cut(s, "\n")
+	return line
+}
+
+func bufioReader(s string) *bufio.Reader {
+	return bufio.NewReader(strings.NewReader(s))
+}
+
+func TestVendorData_multipartWhenExtraProvided(t *testing.T) {
+	t.Parallel()
+	configured := "#cloud-config\nntp:\n  enabled: true\n"
+	got, err := buildVendorData(configured, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.HasPrefix(got, "MIME-Version: 1.0\r\n") {
+		t.Errorf("vendor-data starts with %q, want MIME-Version: 1.0", firstLine(got))
+	}
+	r := textproto.NewReader(bufioReader(got))
+	hdr, err := r.ReadMIMEHeader()
+	if err != nil {
+		t.Fatalf("reading top-level headers: %v", err)
+	}
+	mediaType, params, err := mime.ParseMediaType(hdr.Get("Content-Type"))
+	if err != nil {
+		t.Fatalf("parsing Content-Type %q: %v", hdr.Get("Content-Type"), err)
+	}
+	if mediaType != "multipart/mixed" {
+		t.Errorf("media type = %q, want multipart/mixed", mediaType)
+	}
+	mr := multipart.NewReader(r.R, params["boundary"])
+	type part struct{ contentType, body string }
+	var parts []part
+	for {
+		p, err := mr.NextPart()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			t.Fatalf("NextPart: %v", err)
+		}
+		body, err := io.ReadAll(p)
+		if err != nil {
+			t.Fatalf("reading part: %v", err)
+		}
+		parts = append(parts, part{p.Header.Get("Content-Type"), string(body)})
+	}
+	want := []part{{"text/plain", configured}, {"text/x-shellscript", guestAgentScript}}
+	if len(parts) != len(want) {
+		t.Fatalf("got %d parts, want %d", len(parts), len(want))
+	}
+	for i := range want {
+		if parts[i] != want[i] {
+			t.Errorf("part %d = {%q, %q}, want {%q, %q}", i, parts[i].contentType, firstLine(parts[i].body), want[i].contentType, firstLine(want[i].body))
+		}
+	}
+}
+
+func TestVendorData_offWithoutConfiguredIsEmpty(t *testing.T) {
+	t.Parallel()
+	got, err := buildVendorData("", false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "" {
+		t.Errorf("vendor-data = %q, want empty", got)
+	}
+}
+
+func TestVendorData_offWithConfiguredPassesThrough(t *testing.T) {
+	t.Parallel()
+	configured := "#cloud-config\nntp:\n  enabled: true"
+	got, err := buildVendorData(configured, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != configured {
+		t.Errorf("vendor-data = %q, want the configured document unchanged", got)
+	}
+}