Merge origin/main into feat/335, and pin mesh-host at #98's new head

cmd/mesh-builder/Dockerfile

@@ -11,7 +11,7 @@ WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
 COPY . .
-RUN CGO_ENABLED=0 go build -trimpath -ldflags '-s -w' -o /mesh-builder ./cmd/mesh-builder
+RUN CGO_ENABLED=0 go build -trimpath -buildvcs=false -ldflags '-s -w' -o /mesh-builder ./cmd/mesh-builder
 
 FROM ${ALPINE_BASE}
 # git to clone what it is asked to build, and the docker client to build and push it. The daemon

cmd/mesh-builder/holder.go

@@ -41,6 +41,9 @@ type holder struct {
 	say func(link.HolderState) error
 	// remove runs what a kill needs outside the build: the containers left behind.
 	remove builder.Runner
+	// scratch is where check builds are kept (novox/hq ADR 0350 §5): what the week's sweep lets go of. Nil where
+	// this machine publishes to no artifact store.
+	scratch builder.Scratch
 
 	mu      sync.Mutex
 	paused  bool
@@ -131,6 +134,34 @@ func (h *holder) stateWhilePaused(ctx context.Context, every time.Duration) {
 	}
 }
 
+// expireChecks lets go of every check build older than a week (novox/hq ADR 0350 §5), at start and every while
+// after. Every holder sweeps the one store; what one let go of, another finds gone.
+func (h *holder) expireChecks(ctx context.Context, every time.Duration, now func() time.Time) {
+	sweep := func() {
+		if h.scratch == nil {
+			return
+		}
+		n, err := h.scratch.Expire(ctx, builder.CheckBuildsKept, now())
+		switch {
+		case err != nil:
+			fmt.Fprintf(os.Stderr, "check builds older than %s: %d let go of, and not all: %v\n", builder.CheckBuildsKept, n, err)
+		case n > 0:
+			fmt.Fprintf(os.Stderr, "check builds older than %s: %d check(s)' builds let go of\n", builder.CheckBuildsKept, n)
+		}
+	}
+	sweep()
+	tick := time.NewTicker(every)
+	defer tick.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-tick.C:
+			sweep()
+		}
+	}
+}
+
 // begin records the build this machine took, with the cancel that ends it.
 func (h *holder) begin(request link.BuildRequest, cancel context.CancelFunc) *running {
 	r := &running{request: request, started: time.Now(), cancel: cancel, done: make(chan struct{})}

cmd/mesh-builder/main.go

@@ -18,11 +18,13 @@ package main
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log"
 	"net/url"
 	"os"
 	"os/signal"
+	"sort"
 	"strings"
 	"syscall"
 	"time"
@@ -54,6 +56,8 @@ is dialled except the broker.
   MESH_BINDING       a file the mesh wrote saying where the artifact store is
   MESH_PACKAGE_BINDING  a file the mesh wrote saying where the package registry is
   MESH_NPM_TOKEN_FILE   a file the mesh sealed holding the token for it
+  MESH_GENESIS_PACKAGE_REGISTRY  the document the installer sealed at genesis, read while no
+                     binding is present (novox/hq ADR 0336)
   MESH_NPM_REGISTRY  a package registry URL, when the mesh has not said (a person, the bootstrap)
   MESH_NPM_TOKEN     the token for it, likewise
   MESH_NPM_SCOPE     the scope it answers for (default: @novox)
@@ -108,6 +112,9 @@ func run() error {
 	if err := notReady(); err != nil {
 		return err
 	}
+	// **The builder's own version is part of every reuse key** (novox/hq ADR 0350 §1): a builder that builds
+	// differently never takes a build another one made.
+	builder.Version = builder.SelfVersion(version)
 	if err := undrained(); err != nil {
 		return err
 	}
@@ -193,6 +200,9 @@ func run() error {
 
 	fmt.Fprintf(os.Stderr, "building for the mesh, publishing to %s\n", registry)
 	publisher := builder.Registry{Address: registry, Run: builder.Command}
+	// Check builds are let go of after a week (novox/hq ADR 0350 §5).
+	h.scratch = publisher
+	go h.expireChecks(ctx, time.Hour, time.Now)
 
 	return machine.Take(ctx, func(ctx context.Context, work link.Build) {
 		defer released()
@@ -279,7 +289,11 @@ func answer(ctx context.Context, publisher builder.Publisher, on, workspace stri
 	}
 	say("build", what)
 
-	npmrc, err := packagesFrom()
+	npmrc, err := packagesFrom(on)
+	if err == nil {
+		say("packages", saysRegistry(npmrc))
+	}
+	registryHere, isRegistry := publisher.(builder.Registry)
 	var built builder.Result
 	if request.Check != nil {
 		// **A pull request's merge check, not a build** (novox/hq to-be 45 §9): nothing is built,
@@ -289,12 +303,21 @@ func answer(ctx context.Context, publisher builder.Publisher, on, workspace stri
 		if r, ok := publisher.(builder.Registry); ok {
 			registry = r.Address
 		}
+		spec := checkSpecOf(request)
+		// What the merge would move, built by the check for the walk to take (novox/hq ADR 0350 §1): into the
+		// scratch namespace. **Never with the package registry's credential**: this is code nobody has approved
+		// yet, and a recipe could read the credential it is handed (issue 462). A module that resolves packages
+		// at build time has no reuse key anyway, so nothing is lost by refusing it here.
+		if isRegistry && len(spec.Builds) > 0 {
+			spec.BuildWith = &builder.CheckBuilding{Publish: publisher, Scratch: registryHere, Held: request.Held,
+				Seats: request.Seats}
+		}
 		var v builder.CheckVerdict
-		v, err = builder.Check(building, builder.Command, checkSpecOf(request), workspace, registry, forgeFrom(), say)
+		v, err = builder.Check(building, builder.Command, spec, workspace, registry, forgeFrom(), say)
 		if err == nil {
 			result.Check = &link.CheckOutcome{Verdict: v.Verdict, Summary: v.Summary, Report: v.Report,
 				Took: v.Took.Round(time.Second).String(), Gate: layerOf(v.Gate), RepoCheck: layerOf(v.Repo),
-				Head: v.Head, Trunk: v.Trunk, Beside: v.Beside}
+				Head: v.Head, Trunk: v.Trunk, Beside: v.Beside, Built: checkBuiltOf(v.Built)}
 			// What each of a group's heads was judged as (novox/hq ADR 0323 §6).
 			for _, m := range v.Members {
 				result.Check.Members = append(result.Check.Members, link.CheckedMember{Owner: m.Owner, Repo: m.Repo,
@@ -307,9 +330,30 @@ func answer(ctx context.Context, publisher builder.Publisher, on, workspace stri
 		// after a clone that then fails at npm ci.
 		// Every container it starts is labelled with its id, so a kill finds what outlived the
 		// docker client (ADR 0219).
-		built, err = builder.Build(building, builder.Labelled(builder.Command, request.ID), publisher,
-			request.Repository, request.Path, request.Ref, workspace, request.Held, npmrc,
-			forgeFrom(), say, request.Seats)
+		if request.Reuse != nil && isRegistry && !request.DryRun {
+			// **A walk's build takes the check's build of the same key** (novox/hq ADR 0350 §2).
+			reuse := builder.Reuse{Scratch: registryHere}
+			for _, p := range request.Reuse.Pulls {
+				reuse.Pulls = append(reuse.Pulls, builder.PullRef{Owner: p.Owner, Repo: p.Repo, Number: p.Number})
+			}
+			// Only what a verdict names is taken (ADR 0350 §2).
+			for _, b := range request.Reuse.Builds {
+				named := builder.NamedBuild{Pull: builder.PullRef{Owner: b.Pull.Owner, Repo: b.Pull.Repo,
+					Number: b.Pull.Number}, Check: b.Check, Module: b.Built.Module, Key: b.Built.Key,
+					Digests: map[string]string{}}
+				for _, m := range b.Built.Made {
+					named.Digests[m.Name] = builder.DigestOf(m.Reference)
+				}
+				reuse.Named = append(reuse.Named, named)
+			}
+			built, err = builder.BuildReusing(building, builder.Labelled(builder.Command, request.ID), publisher, reuse,
+				request.Repository, request.Path, request.Ref, workspace, request.Held, npmrc,
+				forgeFrom(), say, request.Seats)
+		} else {
+			built, err = builder.Build(building, builder.Labelled(builder.Command, request.ID), publisher,
+				request.Repository, request.Path, request.Ref, workspace, request.Held, npmrc,
+				forgeFrom(), say, request.Seats)
+		}
 	}
 	// What it copied into the store, whatever became of the build (novox/hq ADR 0257).
 	result.Mirrored = built.Mirrored
@@ -345,6 +389,19 @@ func answer(ctx context.Context, publisher builder.Publisher, on, workspace stri
 			}
 			result.Against = built.Against
 			result.SourceFingerprint = built.Source
+			// What the walk did instead of building, or why it built (novox/hq ADR 0350 §3, §4).
+			result.ReuseKey = built.ReuseKey
+			if built.Reused != nil {
+				f := built.Reused.From
+				result.Reused = built.Reused.Words()
+				result.ReusedFrom = &link.ReusedFrom{Pull: link.PullRef{Owner: f.Pull.Owner, Repo: f.Pull.Repo,
+					Number: f.Pull.Number}, Head: f.Head, Trunk: f.Trunk, Check: f.Check, Key: f.Key}
+			} else if request.Reuse != nil {
+				result.BuiltWhy = built.Why
+				if result.BuiltWhy == "" {
+					result.BuiltWhy = "it has no artifact to build"
+				}
+			}
 			result.Trunk, result.OnTrunk, result.Branches = built.Trunk, built.OnTrunk, built.Branches
 			for _, r := range built.Read {
 				result.Read = append(result.Read, link.ReadRepository{Repository: r.Repository, Ref: r.Ref})
@@ -395,6 +452,10 @@ func checkSpecOf(request link.BuildRequest) builder.CheckSpec {
 	for dir, b := range c.Beside {
 		spec.Beside[dir] = builder.Beside{Repository: b.Repository, Ref: b.Ref}
 	}
+	for _, b := range c.Builds {
+		spec.Builds = append(spec.Builds, builder.CheckBuildSpec{Module: b.Module, Repository: b.Repository, Path: b.Path,
+			Ref: b.Ref, Merged: b.Merged, Tier: b.Tier, Skip: b.Skip})
+	}
 	for _, m := range c.Members {
 		spec.Group = append(spec.Group, builder.GroupHead{Owner: m.Owner, Repo: m.Repo, Repository: m.Repository,
 			Ref: m.Ref, Paths: m.Paths, Base: m.Base})
@@ -402,6 +463,19 @@ func checkSpecOf(request link.BuildRequest) builder.CheckSpec {
 	return spec
 }
 
+// checkBuiltOf is a check's builds for its merge as the outcome carries them (novox/hq ADR 0350 §1).
+func checkBuiltOf(built []builder.CheckBuilt) []link.CheckBuilt {
+	var out []link.CheckBuilt
+	for _, b := range built {
+		c := link.CheckBuilt{Module: b.Module, Key: b.Key, NotBuilt: b.NotBuilt, Took: b.Took.Round(time.Second).String()}
+		for _, m := range b.Made {
+			c.Made = append(c.Made, link.MadeArtifact{Name: m.Name, Kind: m.Kind, Reference: m.Reference})
+		}
+		out = append(out, c)
+	}
+	return out
+}
+
 // layerOf is one layer of a check as the outcome carries it.
 func layerOf(l *builder.Layer) *link.CheckLayer {
 	if l == nil {
@@ -411,79 +485,171 @@ func layerOf(l *builder.Layer) *link.CheckLayer {
 }
 
 // packagesFrom is where a build resolves the mesh's own published packages — the SDK above all
-// (novox/hq ADR 0076, issue 053).
+// (novox/hq ADR 0076, issue 053) — on this machine.
 //
-// Preferably from the mesh: a package-registry binding names the endpoint the way the artifact
-// store's binding does, and a sealed token file the credential the way the broker's does. The
-// environment variables remain for a builder run by a person, and for the bootstrap, where there is
-// no registry yet — there the result is disabled and a build that needs no mesh-published dependency
-// builds anyway.
-func packagesFrom() (builder.Npmrc, error) {
+// **The binding wins, then the genesis document** (novox/hq ADR 0336 §3, §4). The build agent's
+// npm-package-registry requirement is optional: on genesis's node, before the gitea module is assigned,
+// nothing provides it, and the installer sealed the forge it raised to this agent as one document
+// instead. Once the requirement binds, the binding names the endpoint the way the artifact store's
+// does and a sealed token file the credential, and the genesis document is left unread. A binding
+// file named and absent is a requirement not bound here, never a fault: the environment names the
+// path whether or not the mesh wrote it.
+//
+// The environment variables remain for a builder run by a person. With none of the three the result
+// is disabled and says this machine, so a build that needs the registry is refused naming it (§6),
+// and a build that needs none builds anyway.
+func packagesFrom(machine string) (builder.Npmrc, error) {
 	scope := strings.TrimSpace(os.Getenv("MESH_NPM_SCOPE"))
 	if scope == "" {
 		scope = "@novox"
 	}
+	none := builder.Npmrc{Machine: machine}
 
-	registry := strings.TrimSpace(os.Getenv("MESH_NPM_REGISTRY"))
-	var username string
 	if path := strings.TrimSpace(os.Getenv("MESH_PACKAGE_BINDING")); path != "" {
 		raw, err := os.ReadFile(path)
-		if err != nil {
-			return builder.Npmrc{}, fmt.Errorf("cannot read what the mesh said about the package registry: %w", err)
+		switch {
+		case errors.Is(err, os.ErrNotExist):
+			// Not bound on this machine: the genesis document, or nothing.
+		case err != nil:
+			return none, fmt.Errorf("cannot read what the mesh said about the package registry: %w", err)
+		default:
+			return fromBinding(path, raw, scope, machine)
 		}
-		var told struct {
-			From   string         `json:"from"`
-			At     string         `json:"at"`
-			As     string         `json:"as"`
-			Serves map[string]any `json:"serves"`
+	}
+	if path := strings.TrimSpace(os.Getenv("MESH_GENESIS_PACKAGE_REGISTRY")); path != "" {
+		raw, err := os.ReadFile(path)
+		switch {
+		case errors.Is(err, os.ErrNotExist):
+			// Not this mesh's genesis node, or the installer has not sealed it yet.
+		case err != nil:
+			return none, fmt.Errorf("cannot read the genesis document for the package registry: %w", err)
+		default:
+			return fromGenesis(path, raw, scope, machine)
 		}
-		if err := json.Unmarshal(raw, &told); err != nil {
-			return builder.Npmrc{}, fmt.Errorf("%s is not a binding: %w", path, err)
-		}
-		if told.At == "" {
-			return builder.Npmrc{}, fmt.Errorf(
-				"%s says the package registry is on %q and gives no address for it", path, told.From)
-		}
-		// Composed from what the provider serves, so nothing here knows gitea's URL shape from
-		// another registry's: it states its port, the path its registry answers on, and the scheme.
-		scheme := "https"
-		if s, ok := told.Serves["scheme"]; ok {
-			scheme = fmt.Sprintf("%v", s)
-		}
-		port, ok := told.Serves["port"]
-		if !ok {
-			return builder.Npmrc{}, fmt.Errorf("%s says nothing about which port the package registry answers on", path)
-		}
-		npmPath, ok := told.Serves["npm-path"]
-		if !ok {
-			return builder.Npmrc{}, fmt.Errorf("%s says nothing about the path the package registry answers on", path)
-		}
-		registry = fmt.Sprintf("%s://%s:%v%v", scheme, told.At, port, npmPath)
-		username = told.As
 	}
 
-	// The credential the mesh sealed to this machine. The mesh authenticates the ordinary way — a
-	// generated password the provider only applies (novox/hq ADR 0048) — so with a username this is
-	// a password (basic auth); without one it is a bearer token a provider minted.
+	// A builder run by a person.
+	registry := strings.TrimSpace(os.Getenv("MESH_NPM_REGISTRY"))
 	secret := strings.TrimSpace(os.Getenv("MESH_NPM_TOKEN"))
-	if path := strings.TrimSpace(os.Getenv("MESH_NPM_TOKEN_FILE")); path != "" {
-		raw, err := os.ReadFile(path)
+	username := strings.TrimSpace(os.Getenv("MESH_NPM_USER"))
+	if registry == "" && secret == "" {
+		return none, nil
+	}
+	n := builder.Npmrc{Scope: scope, Registry: registry, From: builder.FromEnvironment, Machine: machine}
+	if username != "" {
+		n.Username, n.Password = username, secret
+	} else {
+		n.Token = secret
+	}
+	return n, nil
+}
+
+// fromBinding composes the registry from the npm-package-registry binding the mesh wrote and the
+// credential it sealed beside it. The mesh authenticates the ordinary way — a generated password the
+// provider only applies (novox/hq ADR 0048) — so with a username the secret is a password (basic
+// auth); without one it is a bearer token a provider minted.
+func fromBinding(path string, raw []byte, scope, machine string) (builder.Npmrc, error) {
+	none := builder.Npmrc{Machine: machine}
+	var told struct {
+		From   string         `json:"from"`
+		At     string         `json:"at"`
+		As     string         `json:"as"`
+		Serves map[string]any `json:"serves"`
+	}
+	if err := json.Unmarshal(raw, &told); err != nil {
+		return none, fmt.Errorf("%s is not a binding: %w", path, err)
+	}
+	if told.At == "" {
+		return none, fmt.Errorf(
+			"%s says the package registry is on %q and gives no address for it", path, told.From)
+	}
+	// Composed from what the provider serves, so nothing here knows gitea's URL shape from
+	// another registry's: it states its port, the path its registry answers on, and the scheme.
+	scheme := "https"
+	if s, ok := told.Serves["scheme"]; ok {
+		scheme = fmt.Sprintf("%v", s)
+	}
+	port, ok := told.Serves["port"]
+	if !ok {
+		return none, fmt.Errorf("%s says nothing about which port the package registry answers on", path)
+	}
+	npmPath, ok := told.Serves["npm-path"]
+	if !ok {
+		return none, fmt.Errorf("%s says nothing about the path the package registry answers on", path)
+	}
+	secret := strings.TrimSpace(os.Getenv("MESH_NPM_TOKEN"))
+	if file := strings.TrimSpace(os.Getenv("MESH_NPM_TOKEN_FILE")); file != "" {
+		raw, err := os.ReadFile(file)
 		if err != nil {
-			return builder.Npmrc{}, fmt.Errorf("cannot read this builder's package-registry credential: %w", err)
+			return none, fmt.Errorf("cannot read this builder's package-registry credential: %w", err)
 		}
 		secret = strings.TrimSpace(string(raw))
 	}
-	if u := strings.TrimSpace(os.Getenv("MESH_NPM_USER")); u != "" {
-		username = u
+	n := builder.Npmrc{Scope: scope, Registry: fmt.Sprintf("%s://%s:%v%v", scheme, told.At, port, npmPath),
+		From: builder.FromBinding, Machine: machine}
+	if told.As != "" {
+		n.Username, n.Password = told.As, secret
+	} else {
+		n.Token = secret
 	}
+	return n, nil
+}
 
-	if registry == "" && secret == "" {
-		return builder.Npmrc{}, nil
+// GenesisRegistry is the genesis document (novox/hq ADR 0336 §3): what the installer sealed to the
+// build agent on its node at genesis's packages step, as the `genesis-package-registry` own-secret —
+// the forge it raised, the port this node gave the package registry, its npm path, and the account it
+// made with that account's password. mesh-host writes it; the field names are the two repositories'
+// agreement.
+type GenesisRegistry struct {
+	Scheme   string `json:"scheme"`
+	At       string `json:"at"`
+	Port     int    `json:"port"`
+	NpmPath  string `json:"npm-path"`
+	As       string `json:"as"`
+	Password string `json:"password"`
+}
+
+// fromGenesis composes the registry from the genesis document.
+func fromGenesis(path string, raw []byte, scope, machine string) (builder.Npmrc, error) {
+	none := builder.Npmrc{Machine: machine}
+	var g GenesisRegistry
+	if err := json.Unmarshal(raw, &g); err != nil {
+		return none, fmt.Errorf("%s is not the genesis document for the package registry: %w", path, err)
 	}
-	if username != "" {
-		return builder.Npmrc{Scope: scope, Registry: registry, Username: username, Password: secret}, nil
+	var missing []string
+	for name, value := range map[string]string{"at": g.At, "npm-path": g.NpmPath, "as": g.As, "password": g.Password} {
+		if strings.TrimSpace(value) == "" {
+			missing = append(missing, name)
+		}
 	}
-	return builder.Npmrc{Scope: scope, Registry: registry, Token: secret}, nil
+	if g.Port <= 0 {
+		missing = append(missing, "port")
+	}
+	if len(missing) > 0 {
+		sort.Strings(missing)
+		return none, fmt.Errorf("%s, the genesis document for the package registry, says nothing of %s",
+			path, strings.Join(missing, ", "))
+	}
+	scheme := g.Scheme
+	if scheme == "" {
+		scheme = "http"
+	}
+	return builder.Npmrc{Scope: scope, Registry: fmt.Sprintf("%s://%s:%d%s", scheme, g.At, g.Port, g.NpmPath),
+		Username: g.As, Password: g.Password, From: builder.FromGenesis, Machine: machine}, nil
+}
+
+// saysRegistry is the line each build's log carries about the package registry (novox/hq ADR 0336
+// §4): which of the binding and the genesis document it resolved from, or that it has neither here.
+func saysRegistry(n builder.Npmrc) string {
+	if n.Enabled() {
+		return "the package registry is resolved from " + n.From
+	}
+	machine := n.Machine
+	if machine == "" {
+		machine = "this machine"
+	}
+	return fmt.Sprintf("no package registry: %s is unbound on %s and no genesis document is here; "+
+		"a build needing it is refused", builder.RegistryRequirement, machine)
 }
 
 // forgeFrom is the git credential this builder may offer a clone, composed from the same binding

cmd/mesh-builder/once.go

@@ -84,10 +84,15 @@ func buildOnce(ctx context.Context, args []string) error {
 	}
 	fmt.Fprintln(os.Stderr)
 
-	npmrc, err := packagesFrom()
+	machine := os.Getenv("MESH_NODE")
+	if machine == "" {
+		machine, _ = os.Hostname()
+	}
+	npmrc, err := packagesFrom(machine)
 	if err != nil {
 		return err
 	}
+	fmt.Fprintf(os.Stderr, "  [packages] %s\n", saysRegistry(npmrc))
 	built, buildErr := builder.Build(ctx, builder.Command, publisher, repository, *path, *ref, where, bases, npmrc,
 		forgeFrom(),
 		func(step, message string) { fmt.Fprintf(os.Stderr, "  [%s] %s\n", step, message) })

cmd/mesh-builder/packages_test.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/builder"
+)
+
+// The build agent's package registry (novox/hq ADR 0336, issue 121): its npm-package-registry
+// requirement is optional, so the binding may be absent, and on genesis's node the installer seals
+// the forge it raised as one genesis document instead.
+
+// registryFiles names the three paths the build agent's environment always names, writing only those
+// given.
+func registryFiles(t *testing.T, binding, token, genesis string) {
+	t.Helper()
+	dir := t.TempDir()
+	for env, content := range map[string]string{
+		"MESH_PACKAGE_BINDING":          binding,
+		"MESH_NPM_TOKEN_FILE":           token,
+		"MESH_GENESIS_PACKAGE_REGISTRY": genesis,
+	} {
+		path := filepath.Join(dir, env)
+		t.Setenv(env, path)
+		if content != "" {
+			if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
+				t.Fatal(err)
+			}
+		}
+	}
+	for _, env := range []string{"MESH_NPM_REGISTRY", "MESH_NPM_TOKEN", "MESH_NPM_USER", "MESH_NPM_SCOPE"} {
+		t.Setenv(env, "")
+	}
+}
+
+const (
+	aBinding = `{"from":"gitea","at":"anchor.mesh","as":"anchor-agent",
+	  "serves":{"scheme":"http","port":3000,"npm-path":"/api/packages/novox/npm/"}}`
+	aGenesisDocument = `{"scheme":"http","at":"127.0.0.1","port":3100,"npm-path":"/api/packages/novox/npm/",
+	  "as":"mesh-builder","password":"genesis-secret"}`
+)
+
+func TestUntilTheRequirementBindsTheGenesisDocumentIsRead(t *testing.T) {
+	registryFiles(t, "", "", aGenesisDocument)
+	n, err := packagesFrom("anchor")
+	if err != nil {
+		t.Fatalf("an absent binding beside a genesis document was refused: %v", err)
+	}
+	if n.From != builder.FromGenesis || n.Registry != "http://127.0.0.1:3100/api/packages/novox/npm/" ||
+		n.Username != "mesh-builder" || n.Password != "genesis-secret" || n.Scope != "@novox" {
+		t.Fatalf("the genesis document was not what the registry came from: %+v", n)
+	}
+	file, err := n.File()
+	if err != nil || !strings.Contains(file, "//127.0.0.1:3100/api/packages/novox/npm/:username=mesh-builder") {
+		t.Fatalf("the .npmrc is not written from the genesis document: %v\n%s", err, file)
+	}
+	if got := saysRegistry(n); !strings.Contains(got, "genesis document") {
+		t.Errorf("the log does not say the genesis document: %s", got)
+	}
+}
+
+func TestARealBindingWinsOverTheGenesisDocument(t *testing.T) {
+	registryFiles(t, aBinding, "bound-secret\n", aGenesisDocument)
+	n, err := packagesFrom("anchor")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n.From != builder.FromBinding || n.Registry != "http://anchor.mesh:3000/api/packages/novox/npm/" ||
+		n.Username != "anchor-agent" || n.Password != "bound-secret" {
+		t.Fatalf("the binding did not win over the genesis document: %+v", n)
+	}
+	if got := saysRegistry(n); !strings.Contains(got, "binding") {
+		t.Errorf("the log does not say the binding: %s", got)
+	}
+}
+
+func TestWithNeitherTheAgentHasNoRegistryAndSaysWhere(t *testing.T) {
+	registryFiles(t, "", "", "")
+	n, err := packagesFrom("workstation")
+	if err != nil {
+		t.Fatalf("an unbound optional requirement was a fault: %v", err)
+	}
+	if n.Enabled() || n.Machine != "workstation" {
+		t.Fatalf("a registry came from nowhere: %+v", n)
+	}
+	got := saysRegistry(n)
+	for _, want := range []string{"npm-package-registry", "unbound", "workstation"} {
+		if !strings.Contains(got, want) {
+			t.Errorf("the log does not say %q: %s", want, got)
+		}
+	}
+}
+
+func TestAGenesisDocumentMissingAFieldIsRefusedByName(t *testing.T) {
+	registryFiles(t, "", "", `{"at":"127.0.0.1","port":3000,"npm-path":"/api/packages/novox/npm/","as":"mesh-builder"}`)
+	if _, err := packagesFrom("anchor"); err == nil || !strings.Contains(err.Error(), "password") {
+		t.Fatalf("a genesis document with no password was taken: %v", err)
+	}
+}