f-50: lab: image vérifiée, disques et seeds des VM #50

Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>

internal/lab/provision/provision.go

@@ -0,0 +1,151 @@
+package provision
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	"git.g3e.fr/syonad/two/internal/lab/render"
+	"git.g3e.fr/syonad/two/internal/lab/topology"
+)
+
+const (
+	KeyFile   = "lab_ed25519"
+	KeyLabel  = "two-lab"
+	DiskSize  = "20G"
+	SeedLabel = "cidata"
+
+	ArgsFile = "qemu.args"
+)
+
+var SeedFiles = []string{"user-data", "meta-data", "network-config"}
+
+type Runner interface {
+	Run(ctx context.Context, name string, args ...string) error
+}
+
+type ExecRunner struct{}
+
+func (ExecRunner) Run(ctx context.Context, name string, args ...string) error {
+	out, err := exec.CommandContext(ctx, name, args...).CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("%s: %w: %s", name, err, strings.TrimSpace(string(out)))
+	}
+	return nil
+}
+
+type Options struct {
+	RunDir  string
+	Fetcher Fetcher
+	Runner  Runner
+}
+
+func Prepare(ctx context.Context, p *topology.Plan, o Options) ([]render.Node, error) {
+	if !filepath.IsAbs(o.RunDir) {
+		return nil, fmt.Errorf("run dir %q must be an absolute path", o.RunDir)
+	}
+	if err := os.MkdirAll(o.RunDir, 0o700); err != nil {
+		return nil, err
+	}
+
+	images := map[string]string{}
+	for _, n := range p.Nodes {
+		if _, ok := images[n.Image]; ok {
+			continue
+		}
+		img, ok := imageNamed(p, n.Image)
+		if !ok {
+			return nil, fmt.Errorf("node %s: image %q is not declared", n.Name, n.Image)
+		}
+		base, err := o.Fetcher.Image(ctx, img)
+		if err != nil {
+			return nil, err
+		}
+		images[n.Image] = base
+	}
+
+	key, err := EnsureKey(ctx, o.Runner, o.RunDir)
+	if err != nil {
+		return nil, err
+	}
+	nodes, err := render.Render(p, render.Options{RunDir: o.RunDir, AuthorizedKeys: []string{key}})
+	if err != nil {
+		return nil, err
+	}
+	for i, n := range nodes {
+		if err := Stage(ctx, o.Runner, n, images[p.Nodes[i].Image]); err != nil {
+			return nil, fmt.Errorf("node %s: %w", n.Name, err)
+		}
+	}
+	return nodes, nil
+}
+
+func EnsureKey(ctx context.Context, r Runner, dir string) (string, error) {
+	private := filepath.Join(dir, KeyFile)
+	if _, err := os.Stat(private); errors.Is(err, os.ErrNotExist) {
+		if err := r.Run(ctx, "ssh-keygen", "-q", "-t", "ed25519", "-N", "", "-C", KeyLabel, "-f", private); err != nil {
+			return "", err
+		}
+	} else if err != nil {
+		return "", err
+	}
+	data, err := os.ReadFile(private + ".pub")
+	if err != nil {
+		return "", err
+	}
+	key := strings.TrimSpace(string(data))
+	if key == "" || strings.ContainsAny(key, "\r\n") {
+		return "", fmt.Errorf("%s.pub: not a single public key", private)
+	}
+	return key, nil
+}
+
+func WriteFiles(n render.Node) error {
+	if err := os.MkdirAll(n.Dir, 0o700); err != nil {
+		return err
+	}
+	files := map[string][]byte{
+		ArgsFile:         []byte(strings.Join(n.QEMU, "\n") + "\n"),
+		"meta-data":      n.MetaData,
+		"user-data":      n.UserData,
+		"network-config": n.NetworkConfig,
+	}
+	for name, content := range files {
+		if err := os.WriteFile(filepath.Join(n.Dir, name), content, 0o600); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func Stage(ctx context.Context, r Runner, n render.Node, base string) error {
+	if !filepath.IsAbs(base) {
+		return fmt.Errorf("base image %q must be an absolute path", base)
+	}
+	if err := WriteFiles(n); err != nil {
+		return err
+	}
+	disk := filepath.Join(n.Dir, render.DiskFile)
+	seed := filepath.Join(n.Dir, render.SeedFile)
+	if err := r.Run(ctx, "qemu-img", "create", "-q", "-f", "qcow2", "-F", "qcow2", "-b", base, disk, DiskSize); err != nil {
+		return err
+	}
+	args := []string{"-quiet", "-output", seed, "-volid", SeedLabel, "-joliet", "-rock"}
+	for _, f := range SeedFiles {
+		args = append(args, filepath.Join(n.Dir, f))
+	}
+	return r.Run(ctx, "genisoimage", args...)
+}
+
+func imageNamed(p *topology.Plan, name string) (topology.Image, bool) {
+	for _, i := range p.Images {
+		if i.Name == name {
+			return i, true
+		}
+	}
+	return topology.Image{}, false
+}