mesh-catalog/modules/mesh-build-node/cmd/mesh-build-node/forge_test.go

package main

// The forge side of a build module (novox/hq ADR 0466 §2 and §4, issue 1484). This file is the same for every build
// module: mesh-build-node takes a copy and changes the three constants below.

import (
	"context"
	"encoding/base64"
	"encoding/binary"
	"encoding/json"
	"os"
	"path/filepath"
	"slices"
	"strings"
	"testing"

	"git.novox.be/novox/mesh-sdk/go/forgekey"
)

const (
	forgeModule  = "mesh-build-node"
	forgeHome    = "/var/lib/mesh-build-node"
	forgeModuleD = "../.." // the module's directory, where module.json and files/ are
)

type forgeManifest struct {
	Requires  []any            `json:"requires"`
	State     []any            `json:"state"`
	Resources []map[string]any `json:"resources"`
	Build     struct {
		Artifacts []map[string]any `json:"artifacts"`
	} `json:"build"`
}

func readForgeManifest(t *testing.T) forgeManifest {
	t.Helper()
	raw, err := os.ReadFile(filepath.Join(forgeModuleD, "module.json"))
	if err != nil {
		t.Fatal(err)
	}
	var m forgeManifest
	if err := json.Unmarshal(raw, &m); err != nil {
		t.Fatal(err)
	}
	return m
}

func forgeTemplate(t *testing.T, r map[string]any) string {
	t.Helper()
	name, _ := r["template"].(string)
	if name == "" {
		t.Fatalf("resource %v names no template", r["id"])
	}
	raw, err := os.ReadFile(filepath.Join(forgeModuleD, filepath.FromSlash(name)))
	if err != nil {
		t.Fatalf("resource %v names %s: %v", r["id"], name, err)
	}
	return string(raw)
}

func forgeResource(t *testing.T, m forgeManifest, id string) map[string]any {
	t.Helper()
	for _, r := range m.Resources {
		if r["id"] == id {
			if r["owner"] != forgeModule {
				t.Errorf("%s is owned by %v, not the module's own account", id, r["owner"])
			}
			if p, _ := r["path"].(string); !strings.HasPrefix(p, "${dir:") || strings.Contains(p, "account-home") {
				t.Errorf("%s is at %q: a path of the account's own home (${dir:...}), never the operator's", id, p)
			}
			return r
		}
	}
	t.Fatalf("no resource %q", id)
	return nil
}

var forgeSample = map[string]string{
	"known_host": "[novox.internal]:222 ssh-ed25519 AAAAC3Nza",
	"host_key":   "ssh-ed25519 AAAAC3Nza",
	"ssh_host":   "novox.internal",
	"ssh_alias":  "mesh-forge",
	"ssh_port":   "222",
	"ssh_base":   "ssh://git@novox.internal:222/",
	"https_base": "https://git.novox.be/",
}

// forgeRender fills ${bound:forge-account:<key>} with the sample values, as the provisioner client does.
func forgeRender(t *testing.T, s string) string {
	t.Helper()
	for k, v := range forgeSample {
		s = strings.ReplaceAll(s, "${bound:forge-account:"+k+"}", v)
	}
	if strings.Contains(s, "${") {
		t.Errorf("unfilled placeholder in %q", s)
	}
	return s
}

// 1484/AC1: given sample bound values, the ssh config has Host mesh-forge, IdentitiesOnly yes and the key under the
// module's own home; known_hosts carries the host key; git's config rewrites https_base to ssh://mesh-forge/; no
// ${ is left.
func TestForgeFilesRenderFromTheBoundValuesInTheModulesOwnHome(t *testing.T) {
	m := readForgeManifest(t)

	cfg := forgeResource(t, m, "ssh-config")
	want := "Host mesh-forge\n  HostName novox.internal\n  Port 222\n  HostKeyAlias mesh-forge\n  User git\n  IdentityFile ~/.ssh/mesh_ed25519\n  IdentitiesOnly yes\n"
	if got := forgeRender(t, forgeTemplate(t, cfg)); got != want {
		t.Errorf("ssh config = %q, want %q", got, want)
	}
	if cfg["path"] != "${dir:ssh-dir}/config" || cfg["mode"] != "0600" || cfg["into"] != nil {
		t.Errorf("ssh config resource = %v, want the whole file ${dir:ssh-dir}/config at mode 0600", cfg)
	}

	kh := forgeResource(t, m, "known-hosts")
	if got := strings.TrimSpace(forgeRender(t, forgeTemplate(t, kh))); got != "mesh-forge ssh-ed25519 AAAAC3Nza" {
		t.Errorf("known_hosts = %q", got)
	}

	g := forgeResource(t, m, "git-config")
	wantGit := "[url \"ssh://mesh-forge/\"]\n\tinsteadOf = https://git.novox.be/\n"
	if got := forgeRender(t, forgeTemplate(t, g)); got != wantGit {
		t.Errorf("git config = %q, want %q", got, wantGit)
	}

	dir := forgeResource(t, m, "ssh-dir")
	if dir["mode"] != "0700" || dir["path"] != "${dir:state}/.ssh" {
		t.Errorf("ssh-dir = %v, want ${dir:state}/.ssh at mode 0700", dir)
	}
}

// 1484/AC2: the module requires forge-account, keeps the state keys, and every file resource takes its text from a
// template in the files/ archive (novox/hq ADR 0349 §2).
func TestManifestRequiresForgeAccountKeepsKeysAndTakesFilesFromTemplates(t *testing.T) {
	m := readForgeManifest(t)
	if !slices.Contains(m.Requires, any("forge-account")) {
		t.Errorf("requires = %v, want forge-account among them", m.Requires)
	}
	keeps := false
	for _, s := range m.State {
		if s == "keys" {
			keeps = true
		}
	}
	if !keeps {
		t.Errorf("state = %v lacks keys", m.State)
	}
	files := 0
	for _, r := range m.Resources {
		if _, inline := r["content"]; inline {
			t.Errorf("resource %v keeps its text inline", r["id"])
		}
		if r["type"] == "file" {
			files++
			forgeTemplate(t, r)
		}
	}
	if files == 0 {
		t.Errorf("no file resource: the forge's ssh files are missing")
	}
	packs := 0
	for _, a := range m.Build.Artifacts {
		if a["kind"] == "archive" && a["from"] == "files" && a["name"] == "files" {
			packs++
		}
	}
	if packs != 1 {
		t.Errorf("the build packs files/ into %d archives named files, not one", packs)
	}
}

// forgeEd25519Line is a public key line with a well-formed ed25519 blob.
func forgeEd25519Line(comment string) string {
	blob := []byte{}
	for _, part := range [][]byte{[]byte("ssh-ed25519"), make([]byte, 32)} {
		l := make([]byte, 4)
		binary.BigEndian.PutUint32(l, uint32(len(part)))
		blob = append(append(blob, l...), part...)
	}
	return "ssh-ed25519 " + base64.StdEncoding.EncodeToString(blob) + " " + comment
}

type forgeKeys struct{ puts map[string][]byte }

func (f *forgeKeys) Put(key string, value any) (uint64, error) {
	raw, _ := json.Marshal(value)
	if f.puts == nil {
		f.puts = map[string][]byte{}
	}
	f.puts[key] = raw
	return uint64(len(f.puts)), nil
}

// forgeKeygen stands in for ssh-keygen: it writes the pair the command names.
func forgeKeygen(_ context.Context, _ []string, name string, args ...string) forgekey.Ran {
	var file, comment string
	for i, a := range args {
		switch a {
		case "-f":
			file = args[i+1]
		case "-C":
			comment = args[i+1]
		}
	}
	if name != "ssh-keygen" || file == "" {
		return forgekey.Ran{Status: 1, Stderr: "unexpected"}
	}
	os.WriteFile(file, []byte("PRIVATE\n"), 0o600)
	os.WriteFile(file+".pub", []byte(forgeEd25519Line(comment)+"\n"), 0o644)
	return forgekey.Ran{}
}

// 1484/AC3: given the bundle started with an empty home, the keeper writes <node>.<module> with kind builder, and
// the key is in the home's .ssh.
func TestTheKeeperWritesTheModulesEntryWithKindBuilder(t *testing.T) {
	home, st := t.TempDir(), &forgeKeys{}
	if err := keeperFor(home, "ace", forgeModule, forgeKeygen, st).Once(context.Background()); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(filepath.Join(home, ".ssh", "mesh_ed25519")); err != nil {
		t.Errorf("no key in an empty home: %v", err)
	}
	raw, ok := st.puts["ace."+forgeModule]
	if !ok || len(st.puts) != 1 {
		t.Fatalf("entries = %v, want one at ace.%s", st.puts, forgeModule)
	}
	var e forgekey.KeyEntry
	if err := json.Unmarshal(raw, &e); err != nil {
		t.Fatal(err)
	}
	if e.Kind != "builder" || e.Node != "ace" || e.Account != forgeModule || !strings.HasPrefix(e.Public, "ssh-ed25519 ") {
		t.Errorf("entry = %s", raw)
	}
	if strings.Contains(strings.ToUpper(string(raw)), "PRIVATE") {
		t.Errorf("the entry carries private material: %s", raw)
	}
}

// The home the manifest places is the one the account is given, so the keeper's home and the templates' agree.
func TestTheAccountsHomeIsTheOneTheManifestNames(t *testing.T) {
	m := readForgeManifest(t)
	for _, r := range m.Resources {
		if r["type"] == "user" && r["name"] == forgeModule && r["home"] != forgeHome {
			t.Errorf("the account's home is %v, want %s", r["home"], forgeHome)
		}
	}
}