Let a file resource name a template file in its module's repository: the templates and their tests

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-13 23:57:33 +00:00
parent d43fbc202c
commit 1ce4ab8c2a
3 changed files with 255 additions and 0 deletions
@@ -0,0 +1,94 @@
+package builder
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"path/filepath"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// withTemplateTexts is what was built with each template's text, for a module whose files name templates
+// (novox/hq ADR 0349 §2): its templates archive gains the text of every file in it, read back from the packed
+// bytes, by its path inside the archive. Resolve reads them into the files' content.
+//
+// **Read from the archive, proven by its digest.** The module's files/ is packed again, as the build packs it,
+// and the bytes are read only when they hash to the digest the build made or took: a fresh build's own archive,
+// or a check's build a walk copied by digest without building (novox/hq ADR 0350 §2). Packing is deterministic,
+// so one source packs to one digest; a tree that packs to another is not the archive, and its text is refused.
+func withTemplateTexts(manifest catalogue.Manifest, within string, built []catalogue.Built) ([]catalogue.Built, error) {
+	if !manifest.Templated() {
+		return built, nil
+	}
+	name := catalogue.TemplatesArtifact(manifest)
+	at := -1
+	for i, b := range built {
+		if b.Name == name {
+			at = i
+		}
+	}
+	if name == "" || at < 0 {
+		return nil, fmt.Errorf("%s names templates and built no archive of %s/ to read them from",
+			manifest.Module, catalogue.TemplatesDir)
+	}
+	body, err := pack(filepath.Join(within, catalogue.TemplatesDir))
+	if err != nil {
+		return nil, fmt.Errorf("%s: packing %s/ to read its templates back failed: %w", manifest.Module,
+			catalogue.TemplatesDir, err)
+	}
+	sum := sha256.Sum256(body)
+	digest := "sha256:" + hex.EncodeToString(sum[:])
+	if built[at].Digest != digest {
+		return nil, fmt.Errorf("%s: %s/ packs to the digest %s, and the archive %q built or taken is %s: the "+
+			"templates are read only from the archive the mesh records", manifest.Module, catalogue.TemplatesDir,
+			digest, name, orNone(built[at].Digest))
+	}
+	texts, err := unpackTexts(body)
+	if err != nil {
+		return nil, fmt.Errorf("%s: reading the archive %q back failed: %w", manifest.Module, name, err)
+	}
+	out := append([]catalogue.Built(nil), built...)
+	out[at].Texts = texts
+	return out, nil
+}
+
+// unpackTexts is every file of a packed archive (pack), by its path inside it.
+func unpackTexts(body []byte) (map[string]string, error) {
+	zipped, err := gzip.NewReader(bytes.NewReader(body))
+	if err != nil {
+		return nil, err
+	}
+	defer zipped.Close()
+	reader := tar.NewReader(zipped)
+	texts := map[string]string{}
+	for {
+		header, err := reader.Next()
+		if errors.Is(err, io.EOF) {
+			return texts, nil
+		}
+		if err != nil {
+			return nil, err
+		}
+		if header.Typeflag != tar.TypeReg {
+			continue
+		}
+		text, err := io.ReadAll(reader)
+		if err != nil {
+			return nil, err
+		}
+		texts[header.Name] = string(text)
+	}
+}
+
+func orNone(digest string) string {
+	if digest == "" {
+		return "no digest"
+	}
+	return digest
+}
@@ -0,0 +1,136 @@
+package builder
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// A module's files kept as template files in its repository (novox/hq ADR 0349 §2, design 57 package T1, issue
+// 654): the build packs files/ into the module's templates archive and reads each template's text back from the
+// packed bytes into the file's content, so the manifest the mesh holds is the one it would hold for the text inline.
+
+const templatedModule = `{"module":"meshboard","version":"1",
+  "build":{"artifacts":[
+    {"name":"server","kind":"image","from":"Dockerfile"},
+    {"name":"files","kind":"archive","from":"files"}]},
+  "resources":[
+    {"id":"svc","type":"container","name":"meshboard","artifact":"server"},
+    {"id":"conf","type":"file","path":"/etc/meshboard/meshboard.conf","template":"files/meshboard.conf"},
+    {"id":"deeper","type":"file","path":"/etc/meshboard/deeper.conf","template":"files/a/deeper.conf"}]}`
+
+var templatedFiles = map[string]string{
+	"Dockerfile": "FROM scratch", "files/meshboard.conf": "listen = 8080\n\"quoted\" é\n",
+	"files/a/deeper.conf": "deeper\n", "files/unused.conf": "packed, named by nothing",
+}
+
+func contentOf(t *testing.T, m catalogue.Manifest, id string) string {
+	t.Helper()
+	for _, r := range m.Resources {
+		if r["id"] == id {
+			if _, has := r[catalogue.TemplateField]; has {
+				t.Fatalf("%s still names its template in the built manifest: %v", id, r)
+			}
+			text, ok := r["content"].(string)
+			if !ok {
+				t.Fatalf("%s carries no content: %v", id, r)
+			}
+			return text
+		}
+	}
+	t.Fatalf("no resource %s in %v", id, m.Resources)
+	return ""
+}
+
+func TestABuildReadsEachTemplateBackFromItsArchive(t *testing.T) {
+	r, workspace := aRepository(t, templatedModule, templatedFiles)
+	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "", workspace, nil,
+		Npmrc{}, GitCredential{}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if text := contentOf(t, got.Manifest, "conf"); text != templatedFiles["files/meshboard.conf"] {
+		t.Fatalf("the template's text is %q, not the file's", text)
+	}
+	if text := contentOf(t, got.Manifest, "deeper"); text != templatedFiles["files/a/deeper.conf"] {
+		t.Fatalf("the template's text is %q, not the file's", text)
+	}
+	if r.archives["meshboard/files"] == "" {
+		t.Fatalf("the templates archive was not published: %v", r.archives)
+	}
+	if problem := catalogue.HeldTemplateProblem(got.Manifest); problem != "" {
+		t.Fatal(problem)
+	}
+}
+
+func TestABuildWhoseTemplateIsMissingFailsNamingIt(t *testing.T) {
+	files := map[string]string{}
+	for k, v := range templatedFiles {
+		files[k] = v
+	}
+	delete(files, "files/a/deeper.conf")
+	r, workspace := aRepository(t, templatedModule, files)
+	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "", workspace, nil,
+		Npmrc{}, GitCredential{}, nil)
+	if err == nil || !strings.Contains(err.Error(), "files/a/deeper.conf") {
+		t.Fatalf("a build whose template is missing did not fail naming it: %v", err)
+	}
+}
+
+// A walk that takes its check's build copies the archive by digest and builds nothing: the templates are read back
+// from the tree packed again, which is the archive only when it packs to the digest taken.
+func TestAWalkTakingAChecksBuildReadsTheTemplatesBackToo(t *testing.T) {
+	withVersion(t, "builder-1")
+	contents := map[string]string{"mod/" + ManifestName: templatedModule}
+	for k, v := range templatedFiles {
+		contents["mod/"+k] = v
+	}
+	scratch := newScratch()
+	r, run, workspace := aModuleWith(t, "tree-one", contents)
+	checked := aCheckBuiltBy(t, scratch, r, run, workspace)
+
+	r, run, workspace = aModuleWith(t, "tree-one", contents)
+	got, err := BuildReusing(t.Context(), run, r, Reuse{Scratch: scratch, Pulls: []PullRef{aPull}, Named: named(checked)},
+		"https://forge.invalid/meshboard.git", "mod", "main", workspace, nil, Npmrc{}, GitCredential{}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.Reused == nil || len(r.archives) > 0 {
+		t.Fatalf("the walk built again: reused %+v, why %q, published %v", got.Reused, got.Why, r.archives)
+	}
+	if text := contentOf(t, got.Manifest, "conf"); text != templatedFiles["files/meshboard.conf"] {
+		t.Fatalf("the template's text is %q, not the file's", text)
+	}
+}
+
+// The tree packed again must be the archive taken; text read from anything else is not the archive's.
+func TestTemplateTextsAreRefusedWhenTheTreeDoesNotPackToTheDigestTaken(t *testing.T) {
+	m, err := catalogue.ParseManifest([]byte(templatedModule))
+	if err != nil {
+		t.Fatal(err)
+	}
+	within := writeTree(t, t.TempDir(), templatedFiles)
+	built := []catalogue.Built{{Name: "files", Kind: catalogue.ArtifactArchive, Digest: "sha256:" + strings.Repeat("0", 64)}}
+	if _, err := withTemplateTexts(m, within, built); err == nil || !strings.Contains(err.Error(), "digest") {
+		t.Fatalf("text was read from a tree that does not pack to the archive taken: %v", err)
+	}
+}
+
+// writeTree writes files under dir and answers dir.
+func writeTree(t *testing.T, dir string, files map[string]string) string {
+	t.Helper()
+	for name, body := range files {
+		full := filepath.Join(dir, filepath.FromSlash(name))
+		if err := os.MkdirAll(filepath.Dir(full), 0o755); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(full, []byte(body), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return dir
+}
@@ -0,0 +1,25 @@
+package inventory
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// The manifest the mesh holds carries each file's text (novox/hq ADR 0349 §2): one still naming a template — a
+// build by a builder that predates templates, or a manifest handed over unbuilt — would compose a file with no
+// text, and is refused by name.
+func TestAManifestStillNamingATemplateIsNotRegistered(t *testing.T) {
+	inv := ForTest(t)
+	m := catalogue.Manifest{Module: "notifier", Version: "1", Resources: []map[string]any{
+		{"id": "conf", "type": "file", "path": "/etc/notifier.conf", "template": "files/notifier.conf"}}}
+	err := inv.RegisterModule(t.Context(), m, Source{})
+	if err == nil || !strings.Contains(err.Error(), "files/notifier.conf") {
+		t.Fatalf("a manifest naming a template was registered: %v", err)
+	}
+	m.Resources[0] = map[string]any{"id": "conf", "type": "file", "path": "/etc/notifier.conf", "content": "x"}
+	if err := inv.RegisterModule(t.Context(), m, Source{}); err != nil {
+		t.Fatalf("the same manifest with its text was refused: %v", err)
+	}
+}