Merge pull request 'Fetch templates over HTTP instead of shelling out to git' (#7) from benvin/templates-http into main

Reviewed-on: #7

README.md

@@ -88,7 +88,7 @@ internal/model/      Host/Interface data model (incl. pxe_enabled gate)
 internal/netbox/     NetBox client (reads + pxe_enabled write) + TTL cache, behind an interface
 internal/catalog/    distro catalog: NetBox host -> boot images/kickstart
 internal/render/     text/template engine (swappable Set), selection, loader
-internal/gitsync/    periodic git pull + atomic template reload (last-good)
+internal/gitsync/    periodic templates-tarball fetch + atomic reload (last-good)
 internal/server/     chi HTTP handlers + Prometheus metrics
 templates/           embedded defaults: kickstart, iPXE, catalog/*.yaml
 docs/                see above

cmd/bootapi/main.go

@@ -9,7 +9,6 @@ import (
 	"log/slog"
 	"os"
 	"os/signal"
-	"path/filepath"
 	"syscall"
 
 	"git.unkin.net/unkin/bootapi/internal/config"
@@ -133,10 +132,10 @@ func runValidate(dir string) int {
 	return 0
 }
 
-// buildEngine constructs the render Engine and, when a templates git repo is
-// configured, a Syncer that reloads it periodically. Precedence: git repo →
-// local override dir → embedded defaults only. Git/dir failures degrade to the
-// embedded defaults rather than failing startup.
+// buildEngine constructs the render Engine and, when a templates repo is
+// configured, a Syncer that reloads it periodically. Precedence: templates repo
+// → local override dir → embedded defaults only. Fetch/dir failures degrade to
+// the embedded defaults rather than failing startup.
 func buildEngine(ctx context.Context, cfg *config.Config, rcfg render.RenderConfig) (*render.Engine, *gitsync.Syncer, error) {
 	switch {
 	case cfg.TemplateGitURL != "":
@@ -145,11 +144,10 @@ func buildEngine(ctx context.Context, cfg *config.Config, rcfg render.RenderConf
 			Branch:   cfg.TemplateGitBranch,
 			Token:    cfg.TemplateGitToken,
 			Interval: cfg.TemplateGitInterval,
-			WorkDir:  filepath.Join(os.TempDir(), "bootapi-templates"),
 		}, templates.FS)
 		set, gerr := syncer.Bootstrap(ctx)
 		if gerr != nil {
-			slog.Warn("template git bootstrap degraded to embedded defaults", "err", gerr)
+			slog.Warn("template bootstrap degraded to embedded defaults", "err", gerr)
 		}
 		engine := render.NewEngine(rcfg, set)
 		syncer.SetEngine(engine)

docs/deployment.md

@@ -44,10 +44,9 @@ Create `apps/base/bootapi/` following the argocd-apps `AGENTS.md` pattern:
    as `BOOTAPI_NETBOX_TOKEN_FILE` / `BOOTAPI_PROVISION_TOKEN_FILE` /
    `BOOTAPI_ROOT_PASSWORD_HASH_FILE` (mount the Secret). Least-privilege
    securityContext (`runAsNonRoot`, `drop: [all]`). Baseline resources: requests
-   `512Mi`/`1`, limits `2Gi`/`2` cpu. The pod needs `git` on PATH for template
-   sync (the distroless image includes only the static binary — either add a git
-   layer, use an initContainer that seeds the checkout, or fall back to a
-   ConfigMap; simplest is a small alpine+git base for this service).
+   `512Mi`/`1`, limits `2Gi`/`2` cpu. No `git` binary and no writable volume
+   are needed: template sync is an HTTP fetch of the repo's branch tarball, held
+   in memory.
 6. **Service + exposure**: see the Gateway section below.
 7. Register in `argocd/applicationsets/platform.yaml` (`apps/overlays/*/bootapi`)
    and the platform AppProject destinations.

docs/template-authoring.md

@@ -8,7 +8,8 @@ bootapi ships an embedded default set and lets you override or extend it.
   `templates/ipxe/*.ipxe.tmpl` and `templates/catalog/*.yaml`, compiled into the
   binary (`templates/embed.go`). These are the always-available startup fallback.
 - **Template git repo** (preferred in prod): `BOOTAPI_TEMPLATE_GIT_URL`. bootapi
-  clones it at startup and re-pulls every `BOOTAPI_TEMPLATE_GIT_INTERVAL`
+  fetches the branch tarball (`<repo>/archive/<branch>.tar.gz`) over HTTP at
+  startup and re-fetches every `BOOTAPI_TEMPLATE_GIT_INTERVAL`
   (default 3m, like argocd), atomically swapping the loaded set on change. A
   parse failure keeps the **last-good** set and is only logged + counted
   (`bootapi_template_sync_failures_total`), so a bad push can't take bootapi

internal/config/config.go

@@ -46,14 +46,15 @@ type Config struct {
 	DefaultTemplate string
 
 	// --- template git-sync (preferred over TemplateDir) ---
-	// TemplateGitURL, when set, makes bootapi clone a templates repo and re-pull
+	// TemplateGitURL, when set, makes bootapi fetch a templates repo's branch
+	// tarball over HTTP (<repo>/archive/<branch>.tar.gz) and re-fetch
 	// it every TemplateGitInterval, atomically swapping the loaded set on change
 	// and keeping the last-good set on a parse failure.
 	TemplateGitURL      string
 	TemplateGitBranch   string
 	TemplateGitInterval time.Duration
 	// TemplateGitToken is an optional token for a private templates repo,
-	// injected into the HTTPS clone URL. Empty for a public repo.
+	// sent as a Gitea token header. Empty for a public repo.
 	TemplateGitToken string
 
 	// BaseURL is the http:// base PXE clients use to reach bootapi. It is baked

internal/gitsync/gitsync.go

@@ -1,42 +1,63 @@
-// Package gitsync keeps bootapi's template Set in step with a git repo. It
-// clones the templates repo at startup and re-pulls it every interval (default
-// 3m, like argocd), atomically swapping the Engine's active Set when the repo
-// changes. A parse failure keeps the last-good Set and is only logged/counted,
-// so a bad template push can never take bootapi down. The embedded defaults
-// remain the fallback when git is unreachable at startup.
+// Package gitsync keeps bootapi's template Set in step with the templates repo.
+// It fetches the repo's branch tarball over plain HTTP (Gitea's
+// /archive/<branch>.tar.gz) every interval (default 3m, like argocd), holds the
+// template files in memory, and atomically swaps the Engine's active Set when
+// the content changes. A parse failure keeps the last-good Set and is only
+// logged/counted, so a bad template push can never take bootapi down. The
+// embedded defaults remain the fallback when the repo is unreachable at startup.
+//
+// The repo is only ever read as a file tree plus a change signal, so no git
+// binary is involved: the runtime image stays distroless and the pod needs no
+// writable volume.
 package gitsync
 
 import (
+	"archive/tar"
+	"compress/gzip"
 	"context"
+	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
+	"io"
 	"io/fs"
 	"log/slog"
-	"os"
-	"os/exec"
+	"net/http"
+	"path"
+	"sort"
 	"strings"
 	"sync/atomic"
+	"testing/fstest"
 	"time"
 
 	"git.unkin.net/unkin/bootapi/internal/render"
 )
 
+// maxArchiveBytes caps the downloaded tarball. The templates repo is a handful
+// of text files (~12KB compressed); this only exists to bound a hostile or
+// broken response.
+const maxArchiveBytes = 32 << 20
+
+// maxFileBytes caps a single extracted template.
+const maxFileBytes = 1 << 20
+
 // Options configures the syncer.
 type Options struct {
-	URL      string
+	URL      string // repo URL, e.g. https://git.unkin.net/unkin/bootapi-templates.git
 	Branch   string
-	Token    string // optional; injected into the HTTPS URL for a private repo
+	Token    string // optional; sent as a Gitea token header for a private repo
 	Interval time.Duration
-	WorkDir  string // local checkout path
+	Client   *http.Client // optional; defaults to a 30s-timeout client
 }
 
-// Syncer pulls a templates repo and reloads an Engine on change.
+// Syncer fetches a templates repo and reloads an Engine on change.
 type Syncer struct {
 	opt      Options
 	embedded fs.FS
 	engine   *render.Engine
 
+	digest     string       // content digest of the last fetched tree
 	syncs      atomic.Int64 // successful reloads (Set swapped)
-	failures   atomic.Int64 // pull or parse failures (last-good kept)
+	failures   atomic.Int64 // fetch or parse failures (last-good kept)
 	generation atomic.Int64 // increments on every successful swap
 }
 
@@ -50,6 +71,9 @@ func New(opt Options, embedded fs.FS) *Syncer {
 	if opt.Interval <= 0 {
 		opt.Interval = 3 * time.Minute
 	}
+	if opt.Client == nil {
+		opt.Client = &http.Client{Timeout: 30 * time.Second}
+	}
 	return &Syncer{opt: opt, embedded: embedded}
 }
 
@@ -61,35 +85,46 @@ func (s *Syncer) Syncs() int64      { return s.syncs.Load() }
 func (s *Syncer) Failures() int64   { return s.failures.Load() }
 func (s *Syncer) Generation() int64 { return s.generation.Load() }
 
-// Bootstrap clones the repo and builds the initial Set from embedded + the
-// checkout. On any git/parse failure it returns an embedded-only Set plus a
-// non-nil error (which the caller logs but treats as non-fatal, so bootapi
+// ArchiveURL is the branch tarball URL derived from the repo URL.
+func (o Options) ArchiveURL() string {
+	base := strings.TrimSuffix(strings.TrimRight(o.URL, "/"), ".git")
+	return base + "/archive/" + o.Branch + ".tar.gz"
+}
+
+// Bootstrap fetches the repo and builds the initial Set from embedded + the
+// fetched tree. On any fetch/parse failure it returns an embedded-only Set plus
+// a non-nil error (which the caller logs but treats as non-fatal, so bootapi
 // always starts with at least the embedded defaults).
 func (s *Syncer) Bootstrap(ctx context.Context) (*render.Set, error) {
-	if err := s.clone(ctx); err != nil {
-		set, berr := render.BuildSet(s.embedded, nil)
-		if berr != nil {
-			return nil, berr // embedded defaults broken: genuinely fatal
-		}
-		return set, fmt.Errorf("git clone failed, using embedded defaults: %w", err)
-	}
-	set, err := render.BuildSet(s.embedded, os.DirFS(s.opt.WorkDir))
+	tree, digest, commit, err := s.fetch(ctx)
 	if err != nil {
-		emb, berr := render.BuildSet(s.embedded, nil)
-		if berr != nil {
-			return nil, berr
-		}
-		return emb, fmt.Errorf("git templates failed to parse, using embedded defaults: %w", err)
+		return s.embeddedSet(fmt.Errorf("template fetch failed, using embedded defaults: %w", err))
+	}
+	s.digest = digest
+	set, err := render.BuildSet(s.embedded, tree)
+	if err != nil {
+		return s.embeddedSet(fmt.Errorf("fetched templates failed to parse, using embedded defaults: %w", err))
 	}
 	s.generation.Add(1)
+	slog.Info("templates loaded", "commit", commit, "digest", digest)
 	return set, nil
 }
 
+// embeddedSet returns the embedded-only Set alongside the degrade reason. A
+// broken embedded set is genuinely fatal.
+func (s *Syncer) embeddedSet(reason error) (*render.Set, error) {
+	set, err := render.BuildSet(s.embedded, nil)
+	if err != nil {
+		return nil, err
+	}
+	return set, reason
+}
+
 // Run polls the repo every interval until ctx is cancelled.
 func (s *Syncer) Run(ctx context.Context) {
 	t := time.NewTicker(s.opt.Interval)
 	defer t.Stop()
-	slog.Info("template git-sync started", "url", s.opt.URL, "branch", s.opt.Branch, "interval", s.opt.Interval)
+	slog.Info("template sync started", "url", s.opt.ArchiveURL(), "interval", s.opt.Interval)
 	for {
 		select {
 		case <-ctx.Done():
@@ -101,78 +136,133 @@ func (s *Syncer) Run(ctx context.Context) {
 }
 
 func (s *Syncer) pollOnce(ctx context.Context) {
-	changed, head, err := s.pull(ctx)
+	tree, digest, commit, err := s.fetch(ctx)
 	if err != nil {
 		s.failures.Add(1)
-		slog.Error("template git pull failed; keeping last-good set", "err", err)
+		slog.Error("template fetch failed; keeping last-good set", "err", err)
 		return
 	}
-	if !changed {
+	if digest == s.digest {
 		return
 	}
-	set, err := render.BuildSet(s.embedded, os.DirFS(s.opt.WorkDir))
+	// Record the new digest before parsing so an unchanged bad push is counted
+	// once, not on every poll.
+	s.digest = digest
+	set, err := render.BuildSet(s.embedded, tree)
 	if err != nil {
 		s.failures.Add(1)
-		slog.Error("template reload failed to parse; keeping last-good set", "commit", head, "err", err)
+		slog.Error("template reload failed to parse; keeping last-good set", "commit", commit, "err", err)
 		return
 	}
 	s.engine.Swap(set)
 	s.syncs.Add(1)
 	s.generation.Add(1)
-	slog.Info("templates reloaded from git", "commit", head, "generation", s.generation.Load())
+	slog.Info("templates reloaded", "commit", commit, "digest", digest, "generation", s.generation.Load())
 }
 
-// authURL injects a token into the HTTPS clone URL when configured.
-func (s *Syncer) authURL() string {
-	if s.opt.Token == "" {
-		return s.opt.URL
-	}
-	if rest, ok := strings.CutPrefix(s.opt.URL, "https://"); ok {
-		return "https://" + s.opt.Token + "@" + rest
-	}
-	return s.opt.URL
-}
-
-func (s *Syncer) clone(ctx context.Context) error {
-	if err := os.RemoveAll(s.opt.WorkDir); err != nil {
-		return err
-	}
-	return run(ctx, "", "git", "clone", "--depth", "1", "--branch", s.opt.Branch, s.authURL(), s.opt.WorkDir)
-}
-
-// pull fetches origin/branch and hard-resets to it, reporting whether HEAD moved.
-func (s *Syncer) pull(ctx context.Context) (changed bool, head string, err error) {
-	old, _ := s.head(ctx)
-	if err := run(ctx, s.opt.WorkDir, "git", "fetch", "--depth", "1", "origin", s.opt.Branch); err != nil {
-		return false, "", err
-	}
-	if err := run(ctx, s.opt.WorkDir, "git", "reset", "--hard", "origin/"+s.opt.Branch); err != nil {
-		return false, "", err
-	}
-	newHead, err := s.head(ctx)
+// fetch downloads the branch tarball and extracts it into an in-memory FS. The
+// digest is taken over the extracted tree (not the gzip bytes) so a
+// re-compressed but identical archive is not treated as a change. commit is the
+// source commit Gitea advertises in its immutable Link header, for logging only.
+func (s *Syncer) fetch(ctx context.Context) (fs.FS, string, string, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, s.opt.ArchiveURL(), nil)
 	if err != nil {
-		return false, "", err
+		return nil, "", "", err
 	}
-	return old != newHead, newHead, nil
-}
-
-func (s *Syncer) head(ctx context.Context) (string, error) {
-	out, err := output(ctx, s.opt.WorkDir, "git", "rev-parse", "HEAD")
-	return strings.TrimSpace(out), err
-}
-
-func run(ctx context.Context, dir, name string, args ...string) error {
-	cmd := exec.CommandContext(ctx, name, args...)
-	cmd.Dir = dir
-	if out, err := cmd.CombinedOutput(); err != nil {
-		return fmt.Errorf("%s %s: %w: %s", name, strings.Join(args, " "), err, strings.TrimSpace(string(out)))
+	if s.opt.Token != "" {
+		req.Header.Set("Authorization", "token "+s.opt.Token)
 	}
-	return nil
+	resp, err := s.opt.Client.Do(req)
+	if err != nil {
+		return nil, "", "", err
+	}
+	defer func() { _ = resp.Body.Close() }()
+	if resp.StatusCode != http.StatusOK {
+		return nil, "", "", fmt.Errorf("GET %s: %s", s.opt.ArchiveURL(), resp.Status)
+	}
+
+	tree, err := extract(io.LimitReader(resp.Body, maxArchiveBytes))
+	if err != nil {
+		return nil, "", "", err
+	}
+	if len(tree) == 0 {
+		return nil, "", "", fmt.Errorf("archive contained no files")
+	}
+	return tree, digest(tree), commitFromLink(resp.Header.Get("Link")), nil
 }
 
-func output(ctx context.Context, dir, name string, args ...string) (string, error) {
-	cmd := exec.CommandContext(ctx, name, args...)
-	cmd.Dir = dir
-	out, err := cmd.Output()
-	return string(out), err
+// extract reads a gzipped tar and returns its regular files keyed by path with
+// the archive's single top-level directory stripped (Gitea prefixes every entry
+// with "<repo>/"). Entries that would escape the tree are skipped rather than
+// trusted: the archive is a network input.
+func extract(r io.Reader) (fstest.MapFS, error) {
+	gz, err := gzip.NewReader(r)
+	if err != nil {
+		return nil, fmt.Errorf("gzip: %w", err)
+	}
+	defer func() { _ = gz.Close() }()
+
+	out := fstest.MapFS{}
+	tr := tar.NewReader(gz)
+	for {
+		h, err := tr.Next()
+		if err == io.EOF {
+			return out, nil
+		}
+		if err != nil {
+			return nil, fmt.Errorf("tar: %w", err)
+		}
+		if h.Typeflag != tar.TypeReg {
+			continue
+		}
+		name := stripRoot(h.Name)
+		if name == "" || !fs.ValidPath(name) {
+			continue
+		}
+		b, err := io.ReadAll(io.LimitReader(tr, maxFileBytes))
+		if err != nil {
+			return nil, fmt.Errorf("tar %s: %w", h.Name, err)
+		}
+		out[name] = &fstest.MapFile{Data: b, Mode: 0o444}
+	}
+}
+
+// stripRoot removes the archive's leading directory component.
+func stripRoot(name string) string {
+	clean := path.Clean(strings.TrimPrefix(name, "./"))
+	if strings.HasPrefix(clean, "/") || strings.HasPrefix(clean, "..") {
+		return ""
+	}
+	_, rest, ok := strings.Cut(clean, "/")
+	if !ok {
+		return ""
+	}
+	return rest
+}
+
+// digest hashes the extracted tree: every path and its contents, in path order.
+func digest(tree fstest.MapFS) string {
+	names := make([]string, 0, len(tree))
+	for n := range tree {
+		names = append(names, n)
+	}
+	sort.Strings(names)
+
+	h := sha256.New()
+	for _, n := range names {
+		_, _ = fmt.Fprintf(h, "%s\x00%d\x00", n, len(tree[n].Data))
+		_, _ = h.Write(tree[n].Data)
+	}
+	return hex.EncodeToString(h.Sum(nil))[:16]
+}
+
+// commitFromLink pulls the commit SHA out of Gitea's immutable-archive Link
+// header: <.../archive/<sha>.tar.gz?rev=<sha>>; rel="immutable".
+func commitFromLink(link string) string {
+	_, rev, ok := strings.Cut(link, "rev=")
+	if !ok {
+		return ""
+	}
+	sha, _, _ := strings.Cut(rev, ">")
+	return strings.TrimSpace(sha)
 }

internal/gitsync/gitsync_test.go

@@ -1,11 +1,14 @@
 package gitsync
 
 import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
 	"context"
-	"os"
-	"os/exec"
-	"path/filepath"
+	"net/http"
+	"net/http/httptest"
 	"strings"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -14,31 +17,81 @@ import (
 	"git.unkin.net/unkin/bootapi/templates"
 )
 
-// gitRepo creates a real git repo at dir with an initial almalinux9 override.
-func gitRepo(t *testing.T, dir string) {
+// archive builds a gzipped tar shaped like Gitea's: every entry under a single
+// "<repo>/" root, plus the directory entries Gitea includes.
+func archive(t *testing.T, files map[string]string) []byte {
 	t.Helper()
-	gitCmd(t, "", "git", "init", "-b", "main", dir)
-	gitCmd(t, dir, "git", "config", "user.email", "t@example.net")
-	gitCmd(t, dir, "git", "config", "user.name", "test")
-	writeKS(t, dir, "GITSYNC-V1 {{ .Hostname }}\n")
-	gitCmd(t, dir, "git", "add", "-A")
-	gitCmd(t, dir, "git", "commit", "-m", "v1")
-}
-
-func writeKS(t *testing.T, dir, body string) {
-	t.Helper()
-	if err := os.WriteFile(filepath.Join(dir, "almalinux9.ks.tmpl"), []byte(body), 0o600); err != nil {
+	var buf bytes.Buffer
+	gz := gzip.NewWriter(&buf)
+	tw := tar.NewWriter(gz)
+	if err := tw.WriteHeader(&tar.Header{Name: "bootapi-templates/", Typeflag: tar.TypeDir, Mode: 0o755}); err != nil {
 		t.Fatal(err)
 	}
+	for name, body := range files {
+		h := &tar.Header{Name: "bootapi-templates/" + name, Typeflag: tar.TypeReg, Mode: 0o644, Size: int64(len(body))}
+		if err := tw.WriteHeader(h); err != nil {
+			t.Fatal(err)
+		}
+		if _, err := tw.Write([]byte(body)); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := tw.Close(); err != nil {
+		t.Fatal(err)
+	}
+	if err := gz.Close(); err != nil {
+		t.Fatal(err)
+	}
+	return buf.Bytes()
 }
 
-func gitCmd(t *testing.T, dir, name string, args ...string) {
+// repo serves a mutable archive at Gitea's /archive path and counts requests.
+type repo struct {
+	t       *testing.T
+	srv     *httptest.Server
+	body    atomic.Value // []byte
+	status  atomic.Int64
+	fetches atomic.Int64
+}
+
+func newRepo(t *testing.T, files map[string]string) *repo {
 	t.Helper()
-	cmd := exec.Command(name, args...)
-	cmd.Dir = dir
-	if out, err := cmd.CombinedOutput(); err != nil {
-		t.Fatalf("%s %v: %v: %s", name, args, err, out)
+	r := &repo{t: t}
+	r.body.Store(archive(t, files))
+	r.status.Store(http.StatusOK)
+	mux := http.NewServeMux()
+	mux.HandleFunc("/unkin/bootapi-templates/archive/main.tar.gz", func(w http.ResponseWriter, _ *http.Request) {
+		r.fetches.Add(1)
+		if code := int(r.status.Load()); code != http.StatusOK {
+			w.WriteHeader(code)
+			return
+		}
+		w.Header().Set("Link", `<https://git.example.net/api/v1/repos/unkin/bootapi-templates/archive/abc123.tar.gz?rev=abc123>; rel="immutable"`)
+		_, _ = w.Write(r.body.Load().([]byte))
+	})
+	r.srv = httptest.NewServer(mux)
+	t.Cleanup(r.srv.Close)
+	return r
+}
+
+func (r *repo) url() string                  { return r.srv.URL + "/unkin/bootapi-templates.git" }
+func (r *repo) push(files map[string]string) { r.body.Store(archive(r.t, files)) }
+func ks(body string) map[string]string       { return map[string]string{"almalinux9.ks.tmpl": body} }
+
+func syncer(t *testing.T, r *repo) *Syncer {
+	t.Helper()
+	return New(Options{URL: r.url(), Branch: "main", Interval: time.Hour}, templates.FS)
+}
+
+func engineFor(t *testing.T, s *Syncer) *render.Engine {
+	t.Helper()
+	set, err := s.Bootstrap(context.Background())
+	if err != nil {
+		t.Fatalf("Bootstrap: %v", err)
 	}
+	eng := render.NewEngine(render.RenderConfig{DefaultTemplate: "almalinux9", ArtifactBase: "https://af"}, set)
+	s.SetEngine(eng)
+	return eng
 }
 
 func renderKS(t *testing.T, e *render.Engine) string {
@@ -51,33 +104,32 @@ func renderKS(t *testing.T, e *render.Engine) string {
 	return string(out)
 }
 
+func TestArchiveURL(t *testing.T) {
+	for _, tc := range []struct{ in, want string }{
+		{"https://git.unkin.net/unkin/bootapi-templates.git", "https://git.unkin.net/unkin/bootapi-templates/archive/main.tar.gz"},
+		{"https://git.unkin.net/unkin/bootapi-templates", "https://git.unkin.net/unkin/bootapi-templates/archive/main.tar.gz"},
+		{"https://git.unkin.net/unkin/bootapi-templates/", "https://git.unkin.net/unkin/bootapi-templates/archive/main.tar.gz"},
+	} {
+		if got := (Options{URL: tc.in, Branch: "main"}).ArchiveURL(); got != tc.want {
+			t.Errorf("ArchiveURL(%q) = %q, want %q", tc.in, got, tc.want)
+		}
+	}
+}
+
 func TestBootstrapAndReload(t *testing.T) {
-	if _, err := exec.LookPath("git"); err != nil {
-		t.Skip("git not available")
-	}
-	src := t.TempDir()
-	gitRepo(t, src)
+	r := newRepo(t, ks("SYNC-V1 {{ .Hostname }}\n"))
+	s := syncer(t, r)
+	eng := engineFor(t, s)
 
-	s := New(Options{URL: src, Branch: "main", Interval: time.Hour, WorkDir: filepath.Join(t.TempDir(), "co")}, templates.FS)
-	set, err := s.Bootstrap(context.Background())
-	if err != nil {
-		t.Fatalf("Bootstrap: %v", err)
-	}
-	eng := render.NewEngine(render.RenderConfig{DefaultTemplate: "almalinux9", ArtifactBase: "https://af"}, set)
-	s.SetEngine(eng)
-
-	if got := renderKS(t, eng); !contains(got, "GITSYNC-V1 web01") {
+	if got := renderKS(t, eng); !strings.Contains(got, "SYNC-V1 web01") {
 		t.Fatalf("initial render missing v1 override:\n%s", got)
 	}
 	gen1 := s.Generation()
 
-	// Commit v2 upstream, then poll: the engine must swap to the new content.
-	writeKS(t, src, "GITSYNC-V2 {{ .Hostname }}\n")
-	gitCmd(t, src, "git", "add", "-A")
-	gitCmd(t, src, "git", "commit", "-m", "v2")
-
+	r.push(ks("SYNC-V2 {{ .Hostname }}\n"))
 	s.pollOnce(context.Background())
-	if got := renderKS(t, eng); !contains(got, "GITSYNC-V2 web01") {
+
+	if got := renderKS(t, eng); !strings.Contains(got, "SYNC-V2 web01") {
 		t.Fatalf("after reload, render missing v2:\n%s", got)
 	}
 	if s.Generation() <= gen1 {
@@ -88,30 +140,33 @@ func TestBootstrapAndReload(t *testing.T) {
 	}
 }
 
-func TestReloadKeepsLastGoodOnParseError(t *testing.T) {
-	if _, err := exec.LookPath("git"); err != nil {
-		t.Skip("git not available")
-	}
-	src := t.TempDir()
-	gitRepo(t, src)
-
-	s := New(Options{URL: src, Branch: "main", Interval: time.Hour, WorkDir: filepath.Join(t.TempDir(), "co")}, templates.FS)
-	set, err := s.Bootstrap(context.Background())
-	if err != nil {
-		t.Fatal(err)
-	}
-	eng := render.NewEngine(render.RenderConfig{DefaultTemplate: "almalinux9", ArtifactBase: "https://af"}, set)
-	s.SetEngine(eng)
-
-	// Push a template that fails to parse.
-	writeKS(t, src, "BROKEN {{ .Hostname \n")
-	gitCmd(t, src, "git", "add", "-A")
-	gitCmd(t, src, "git", "commit", "-m", "broken")
+func TestUnchangedContentDoesNotReload(t *testing.T) {
+	r := newRepo(t, ks("SYNC-V1 {{ .Hostname }}\n"))
+	s := syncer(t, r)
+	engineFor(t, s)
 
+	// Re-archiving the same files yields fresh gzip bytes; the digest is taken
+	// over the extracted tree, so this must NOT count as a change.
+	r.push(ks("SYNC-V1 {{ .Hostname }}\n"))
 	s.pollOnce(context.Background())
 
-	// The last-good v1 set must still be served, and a failure recorded.
-	if got := renderKS(t, eng); !contains(got, "GITSYNC-V1 web01") {
+	if s.Syncs() != 0 {
+		t.Errorf("syncs = %d, want 0 (identical content is not a change)", s.Syncs())
+	}
+	if s.Failures() != 0 {
+		t.Errorf("failures = %d, want 0", s.Failures())
+	}
+}
+
+func TestReloadKeepsLastGoodOnParseError(t *testing.T) {
+	r := newRepo(t, ks("SYNC-V1 {{ .Hostname }}\n"))
+	s := syncer(t, r)
+	eng := engineFor(t, s)
+
+	r.push(ks("BROKEN {{ .Hostname \n"))
+	s.pollOnce(context.Background())
+
+	if got := renderKS(t, eng); !strings.Contains(got, "SYNC-V1 web01") {
 		t.Fatalf("last-good not kept after parse failure:\n%s", got)
 	}
 	if s.Failures() != 1 {
@@ -120,11 +175,19 @@ func TestReloadKeepsLastGoodOnParseError(t *testing.T) {
 	if s.Syncs() != 0 {
 		t.Errorf("syncs = %d, want 0 (bad push must not count as a sync)", s.Syncs())
 	}
+
+	// The same bad content on the next poll must not be counted again.
+	s.pollOnce(context.Background())
+	if s.Failures() != 1 {
+		t.Errorf("failures = %d, want 1 (an unchanged bad push is counted once)", s.Failures())
+	}
 }
 
 func TestBootstrapDegradesToEmbedded(t *testing.T) {
-	// A bogus URL must not fail startup: Bootstrap returns the embedded set.
-	s := New(Options{URL: "/nonexistent/repo", Branch: "main", Interval: time.Hour, WorkDir: filepath.Join(t.TempDir(), "co")}, templates.FS)
+	r := newRepo(t, ks("SYNC-V1 {{ .Hostname }}\n"))
+	r.status.Store(http.StatusNotFound)
+	s := syncer(t, r)
+
 	set, err := s.Bootstrap(context.Background())
 	if err == nil {
 		t.Error("expected a non-nil (non-fatal) error describing the degrade")
@@ -133,10 +196,43 @@ func TestBootstrapDegradesToEmbedded(t *testing.T) {
 		t.Fatal("expected the embedded fallback Set, got nil")
 	}
 	eng := render.NewEngine(render.RenderConfig{DefaultTemplate: "almalinux9", ArtifactBase: "https://af"}, set)
-	// Embedded almalinux9 template still renders.
-	if got := renderKS(t, eng); !contains(got, "rootpw") {
+	if got := renderKS(t, eng); !strings.Contains(got, "rootpw") {
 		t.Errorf("embedded fallback did not render a real kickstart:\n%s", got)
 	}
 }
 
-func contains(s, sub string) bool { return strings.Contains(s, sub) }
+func TestExtractStripsRootAndSkipsEscapes(t *testing.T) {
+	tree, err := extract(bytes.NewReader(archive(t, map[string]string{
+		"catalog/almalinux9.yaml": "name: almalinux9\n",
+		"../escape.ks.tmpl":       "nope\n",
+	})))
+	if err != nil {
+		t.Fatalf("extract: %v", err)
+	}
+	if _, ok := tree["catalog/almalinux9.yaml"]; !ok {
+		t.Errorf("root not stripped; got keys %v", keys(tree))
+	}
+	for k := range tree {
+		if strings.Contains(k, "escape") {
+			t.Errorf("traversal entry was kept: %q", k)
+		}
+	}
+}
+
+func TestCommitFromLink(t *testing.T) {
+	link := `<https://git.unkin.net/api/v1/repos/unkin/bootapi-templates/archive/5df1894.tar.gz?rev=5df1894>; rel="immutable"`
+	if got := commitFromLink(link); got != "5df1894" {
+		t.Errorf("commitFromLink = %q, want 5df1894", got)
+	}
+	if got := commitFromLink(""); got != "" {
+		t.Errorf("commitFromLink(\"\") = %q, want empty", got)
+	}
+}
+
+func keys[V any](m map[string]V) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	return out
+}