Bring F3 up to its release branch, with both sides' store tests (part 5 of 14)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/builder/builder.go

@@ -268,7 +268,14 @@ func build(ctx context.Context, run Runner, publish Publisher,
 	}
 	// What is judged only where a definition is written (novox/hq ADR 0326 §3, issue 574): a build is
 	// where a changed definition is first read, so it is refused here before anything is made of it.
-	if problems := catalogue.WrittenSettingsProblems(manifest); len(problems) > 0 {
+	// Judged with each template's text in its file, as written in the tree (novox/hq ADR 0349 §2): a template the
+	// module's directory lacks is refused here, before anything is built.
+	judged, err := catalogue.WithTemplatesFrom(manifest, within)
+	if err != nil {
+		say("manifest", "INVALID: %v", err)
+		return Result{}, err
+	}
+	if problems := catalogue.WrittenSettingsProblems(judged); len(problems) > 0 {
 		err := fmt.Errorf("%s", strings.Join(problems, "; "))
 		say("manifest", "INVALID: %v", err)
 		return Result{}, err
@@ -410,6 +417,11 @@ func build(ctx context.Context, run Runner, publish Publisher,
 		}
 	}
 
+	// Each template's text, read back from the archive the build made or took (novox/hq ADR 0349 §2).
+	if built, err = withTemplateTexts(manifest, within, built); err != nil {
+		say("templates", "FAILED: %v", err)
+		return Result{}, err
+	}
 	resolved, err := manifest.Resolve(built)
 	if err != nil {
 		say("resolve", "FAILED: %v", err)
@@ -1076,6 +1088,16 @@ func one(ctx context.Context, run Runner, publish Publisher,
 			return catalogue.Built{}, fmt.Errorf("%s: building %s failed: %w", module, a.Name, err)
 		}
 		say("image", "built, publishing")
+		// Its bases linked into its repository first, so the push needs none of their blobs from this
+		// machine's store, which may not hold them (novox/hq issue 694). Said and not fatal: a push
+		// from a store that holds them works without, and one that fails says which blob it lacked.
+		if lender, can := publish.(BaseLender); can {
+			if n, err := lender.LendBases(ctx, module+"/"+a.Name, buildArgValues(args)); err != nil {
+				say("image", "its bases could not all be linked into %s/%s before the push: %v", module, a.Name, err)
+			} else if n > 0 {
+				say("image", "%d blob(s) of its bases linked into %s/%s before the push", n, module, a.Name)
+			}
+		}
 		reference, err := publish.PublishImage(ctx, local, module+"/"+a.Name)
 		if err != nil {
 			return catalogue.Built{}, err
@@ -1427,6 +1449,19 @@ func standingOn(ctx context.Context, manifest catalogue.Manifest, held map[strin
 	return args, resolved, nil
 }
 
+// buildArgValues is what each --build-arg of a build was handed: the bases, as this mesh holds them.
+func buildArgValues(args []string) []string {
+	var values []string
+	for i := 0; i+1 < len(args); i += 2 {
+		if args[i] == "--build-arg" {
+			if _, value, has := strings.Cut(args[i+1], "="); has {
+				values = append(values, value)
+			}
+		}
+	}
+	return values
+}
+
 // compile runs a module's own code through its toolchain, and says where the result is.
 //
 // **In the module's own directory, under the path the toolchain expects.** A module is compiled

internal/builder/check.go

@@ -103,6 +103,23 @@ type CheckSpec struct {
 	// for the walk to take. None for a group's composed check, whose members' own checks build.
 	Builds    []CheckBuildSpec
 	BuildWith *CheckBuilding
+	// Tests and StoreOnly narrow what the repository's own script runs, for a branch tried before its pull
+	// request (novox/hq issue 686): handed to the script as EnvTests and EnvStoreOnly, which it may read.
+	Tests     string
+	StoreOnly bool
+}
+
+// selection is what a check hands the repository's script to narrow what it runs (novox/hq issue 686): nothing
+// for a pull request's check, which always runs whole.
+func selection(spec CheckSpec) []string {
+	var env []string
+	if spec.Tests != "" {
+		env = append(env, EnvTests+"="+spec.Tests)
+	}
+	if spec.StoreOnly {
+		env = append(env, EnvStoreOnly+"=1")
+	}
+	return env
 }
 
 // GroupHead is one other head of a delivery group's composed check.
@@ -193,6 +210,11 @@ const (
 	// EnvGroup is a delivery group's other heads, as JSON, for the gate (novox/hq ADR 0239); empty for a
 	// pull request checked alone.
 	EnvGroup = "MESH_CHECK_GROUP"
+	// EnvTests is a `go test -run` pattern and EnvStoreOnly is 1 when a branch tried before its pull request
+	// asks for only those tests, or only the store tests (novox/hq issue 686). Never set for a pull request's
+	// check. A script that reads neither runs whole.
+	EnvTests     = "MESH_CHECK_TESTS"
+	EnvStoreOnly = "MESH_CHECK_STORE_ONLY"
 )
 
 // CheckTimeout bounds one check; a check that runs past it is an error, not a pass.
@@ -515,6 +537,7 @@ func Check(ctx context.Context, run Runner, spec CheckSpec, workspace, registry
 		EnvModules + "=" + strings.Join(append(append([]string{}, spec.Modules...), spec.New...), ","),
 		EnvGroup + "=" + groupFile,
 		"GOCACHE=" + filepath.Join(workspace, "go-cache"), "GOMODCACHE=" + filepath.Join(workspace, "go-modules")}
+	env = append(env, selection(spec)...)
 
 	v := CheckVerdict{}
 	modules := append(append([]string{}, spec.Modules...), prefixed("new:", spec.New)...)

internal/builder/check_test.go

@@ -590,3 +590,15 @@ func TestARepositoryInTwoLanguagesIsCheckedInBoth(t *testing.T) {
 		t.Errorf("a part in a toolchain the mesh does not hold answered %+v — never a pass", layer)
 	}
 }
+
+// A branch tried before its pull request may narrow what the repository's script runs (novox/hq issue 686); a
+// pull request's check is handed nothing, and runs whole.
+func TestOnlyATrysSelectionReachesTheScript(t *testing.T) {
+	if env := selection(CheckSpec{Number: 7}); len(env) != 0 {
+		t.Fatalf("a pull request's check was handed a selection: %v", env)
+	}
+	env := selection(CheckSpec{Tests: "^TestX$", StoreOnly: true})
+	if len(env) != 2 || env[0] != "MESH_CHECK_TESTS=^TestX$" || env[1] != "MESH_CHECK_STORE_ONLY=1" {
+		t.Fatalf("a try's selection: %v", env)
+	}
+}

internal/builder/lend.go

@@ -0,0 +1,178 @@
+package builder
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"runtime"
+	"strings"
+)
+
+// **A built image's bases are linked into its repository before it is pushed** (novox/hq issue 694).
+//
+// A push reads every blob of the image out of this machine's store, unless the repository it goes to
+// already holds that blob: the runtime asks the registry first, blob by blob, and reads locally only
+// what the registry lacks. A runtime keeping its images in containerd's store — the default for a
+// fresh install from docker 29 on — does not always hold the compressed layers of the base an image
+// was built FROM: a layer whose unpacked form it already had is never fetched. The push of such an
+// image then fails on a layer this machine never had ("not all of them are available locally"), while
+// the very bytes sit in this registry, under the repository the base was mirrored into.
+//
+// So the base's blobs are mounted into the image's repository first. A mount moves no bytes, and once
+// the repository holds a blob the push asks this machine for nothing of it — whichever store the
+// runtime keeps. A runtime that holds every layer (the classic store) is not changed by this: its push
+// finds the same blobs already there.
+
+// BaseLender links what a build's bases hold into the repository its image is about to be pushed to.
+type BaseLender interface {
+	// LendBases mounts every blob of each base this registry holds — for the platform this machine
+	// builds — into `repository`, and answers how many it mounted.
+	LendBases(ctx context.Context, repository string, bases []string) (int, error)
+}
+
+// platformed is an index's entry: a manifest and the platform it is for.
+type platformed struct {
+	descriptor
+	Platform *struct {
+		OS           string `json:"os"`
+		Architecture string `json:"architecture"`
+	} `json:"platform"`
+}
+
+// LendBases mounts each base's blobs into the repository. A base this registry does not hold under its
+// repository — named by tag, or held somewhere else — lends nothing and is no error: the push reads it
+// from this machine's store as before.
+func (r Registry) LendBases(ctx context.Context, repository string, bases []string) (int, error) {
+	mounted := 0
+	for _, base := range bases {
+		name, digest, pinned := strings.Cut(base, "@")
+		if !pinned || !strings.HasPrefix(digest, "sha256:") {
+			continue
+		}
+		where, err := parseReference(name + "@" + digest)
+		if err != nil {
+			continue
+		}
+		from := where.repository
+		if from == repository {
+			continue
+		}
+		blobs, held, err := r.blobsOf(ctx, from, digest)
+		if err != nil {
+			return mounted, fmt.Errorf("reading %s: %w", base, err)
+		}
+		if !held {
+			continue
+		}
+		for _, blob := range blobs {
+			did, err := r.mount(ctx, repository, from, blob)
+			if err != nil {
+				return mounted, fmt.Errorf("linking %s of %s into %s: %w", blob, base, repository, err)
+			}
+			if did {
+				mounted++
+			}
+		}
+	}
+	return mounted, nil
+}
+
+// blobsOf is the config and layers of the manifest under repository@digest — for an index, of each
+// manifest it names for this machine's platform. False when the registry holds no such manifest there.
+func (r Registry) blobsOf(ctx context.Context, repository, digest string) ([]string, bool, error) {
+	body, held, err := r.manifest(ctx, repository, digest)
+	if err != nil || !held {
+		return nil, held, err
+	}
+	var document struct {
+		Manifests []platformed `json:"manifests"`
+		Config    *descriptor  `json:"config"`
+		Layers    []descriptor `json:"layers"`
+	}
+	if err := json.Unmarshal(body, &document); err != nil {
+		return nil, false, fmt.Errorf("%s@%s is not a manifest: %w", repository, digest, err)
+	}
+	var blobs []string
+	if document.Config != nil {
+		blobs = append(blobs, document.Config.Digest)
+	}
+	for _, l := range document.Layers {
+		blobs = append(blobs, l.Digest)
+	}
+	for _, m := range document.Manifests {
+		if m.Platform == nil || m.Platform.OS != runtime.GOOS || m.Platform.Architecture != runtime.GOARCH {
+			continue
+		}
+		more, held, err := r.blobsOf(ctx, repository, m.Digest)
+		if err != nil {
+			return nil, false, err
+		}
+		if held {
+			blobs = append(blobs, more...)
+		}
+	}
+	return blobs, true, nil
+}
+
+// manifest reads one manifest document from this registry; false when it is not there.
+func (r Registry) manifest(ctx context.Context, repository, digest string) ([]byte, bool, error) {
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet,
+		"http://"+r.Address+"/v2/"+repository+"/manifests/"+digest, nil)
+	if err != nil {
+		return nil, false, err
+	}
+	request.Header.Set("Accept", manifestAccept)
+	response, err := r.client().Do(request)
+	if err != nil {
+		return nil, false, fmt.Errorf("cannot reach the registry at %s: %w", r.Address, err)
+	}
+	defer response.Body.Close()
+	if response.StatusCode == http.StatusNotFound {
+		return nil, false, nil
+	}
+	if response.StatusCode != http.StatusOK {
+		return nil, false, fmt.Errorf("%s/%s@%s: %s", r.Address, repository, digest, response.Status)
+	}
+	body, err := io.ReadAll(io.LimitReader(response.Body, 4<<20))
+	return body, err == nil, err
+}
+
+// mount links one blob from one repository into another; false when the repository already held it.
+func (r Registry) mount(ctx context.Context, repository, from, digest string) (bool, error) {
+	base := "http://" + r.Address + "/v2/" + repository
+	if there, err := r.has(ctx, base+"/blobs/"+digest); err != nil {
+		return false, err
+	} else if there {
+		return false, nil
+	}
+	start, err := http.NewRequestWithContext(ctx, http.MethodPost,
+		base+"/blobs/uploads/?mount="+digest+"&from="+from, nil)
+	if err != nil {
+		return false, err
+	}
+	begun, err := r.client().Do(start)
+	if err != nil {
+		return false, fmt.Errorf("cannot reach the registry at %s: %w", r.Address, err)
+	}
+	begun.Body.Close()
+	if begun.StatusCode == http.StatusCreated {
+		return true, nil
+	}
+	if begun.StatusCode == http.StatusAccepted {
+		// Not mounted, and an upload begun in its place: let go of it, so nothing is left half-open.
+		if location := begun.Header.Get("Location"); location != "" {
+			if strings.HasPrefix(location, "/") {
+				location = "http://" + r.Address + location
+			}
+			if cancel, err := http.NewRequestWithContext(ctx, http.MethodDelete, location, nil); err == nil {
+				if done, err := r.client().Do(cancel); err == nil {
+					done.Body.Close()
+				}
+			}
+		}
+		return false, fmt.Errorf("%s did not mount it from %s", r.Address, from)
+	}
+	return false, fmt.Errorf("%s answered %s when asked to mount it from %s", r.Address, begun.Status, from)
+}