Never make a credential only a person can give, and give it once per provider (hq issue 164, ADR 0337)

A Servarr app's API key, an indexer's key and a downloader's password are values the provider's
software holds; the pair path made a random value for every consumer of them, sealed it to both ends
and reported success, and the provider refused it. An offer may now say `"credential": {"issued-by":
"outside"}`: SecretFor never makes a value for it, the plan reads such a pair as given or not given
and sends the consumer no credential file until a person gives it, without refusing its machine;
remakeShared and SharedSecretFor never make a provider's own secret issued outside either.
`secret accept <provider's node> <provider module> <provision>` seals one value to every consumer that
binds the provision from that provider, the provider and the operator, under one generation; the
per-pair form is refused for such a provision, and rotate names the accept. A consumer may wait for a
provision's credential: the controller excuses the wait only when the store bears it out, and its
needs-operator condition names the one accept line.

Adds the replay of issue 164 (TestReplay164), written with only what the controller had before.

cmd/mesh-controller/outside_accept_test.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// One accept for a provider reaches every consumer that binds the provision from it, and each consumer's send
+// places it; the per-pair form naming a consumer is refused for such a provision, naming the provider's form; a
+// value the mesh made before the rule is not placed (novox/hq ADR 0337 §2, §3, §4, issue 164, issue 165). Needs the
+// store (MESH_TEST_POSTGRES), and is named in testdata/store-tests.
+func TestOneAcceptForAProviderIsPlacedForEveryConsumer(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	// Before the rule: tv's offer said nothing of its credential, and the send made one per pair.
+	register(t, open, catalogue.Manifest{Module: "tv", Version: "1",
+		Provides: []catalogue.Offer{{Name: "tv-api", Scope: catalogue.ScopeMesh}}})
+	for _, m := range []string{"requests", "indexer"} {
+		register(t, open, catalogue.Manifest{Module: m, Version: "1", Requires: []string{"tv-api"},
+			Secrets: map[string]string{"tv-api": "/var/lib/mesh/" + m + "/tv-api.secret"}})
+	}
+	for _, a := range [][2]string{{"anchor", "tv"}, {"laptop", "requests"}, {"laptop", "indexer"}} {
+		if _, err := assign(ctx, open, a[0], a[1]); err != nil {
+			t.Fatal(err)
+		}
+	}
+	placed := func(module string) bool {
+		t.Helper()
+		plan, settings, err := planFor(ctx, open, "laptop")
+		if err != nil {
+			t.Fatalf("laptop was refused: %v", err)
+		}
+		declared, err := declarationFor(ctx, open, "laptop", plan, settings)
+		if err != nil {
+			t.Fatalf("laptop did not compose: %v", err)
+		}
+		for _, r := range declared.Resources {
+			if r["path"] == "/var/lib/mesh/"+module+"/tv-api.secret" && r["sealed"] != nil {
+				return true
+			}
+		}
+		return false
+	}
+
+	if !placed("requests") || !placed("indexer") {
+		t.Fatal("before the rule, the send made and placed a credential per pair")
+	}
+	// The offer now says only a person gives it: the values the mesh made are not placed.
+	register(t, open, catalogue.Manifest{Module: "tv", Version: "2",
+		Provides: []catalogue.Offer{{Name: "tv-api", Scope: catalogue.ScopeMesh,
+			Credential: &catalogue.OfferCredential{IssuedBy: catalogue.IssuedOutside}}}})
+	if placed("requests") || placed("indexer") {
+		t.Fatal("a credential nobody gave was placed")
+	}
+
+	// The per-pair form is refused, naming the provider's form, and reads nothing.
+	file := filepath.Join(t.TempDir(), "key")
+	if err := os.WriteFile(file, []byte("the app's key\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	err := secretCommand(ctx, []string{"accept", "laptop", "requests", "tv-api", "--provider", "anchor", "--from", file})
+	if err == nil || !strings.Contains(err.Error(), "secret accept anchor tv tv-api") {
+		t.Fatalf("the per-pair form was not refused naming the provider's: %v", err)
+	}
+
+	consumers, unresolved, err := consumersFrom(ctx, open, "anchor", "tv", "tv-api")
+	if err != nil || len(unresolved) != 0 {
+		t.Fatalf("the consumers of tv on anchor could not be found: %v %v", err, unresolved)
+	}
+	if len(consumers) != 2 {
+		t.Fatalf("the consumers of tv on anchor are %+v; want requests and indexer on laptop", consumers)
+	}
+	if _, err := open.inventory.AcceptSecretForProvision(ctx, "tv-api", "anchor", "tv", "the app's key", consumers); err != nil {
+		t.Fatal(err)
+	}
+	if !placed("requests") || !placed("indexer") {
+		t.Fatal("the value given once for the provider was not placed for every consumer")
+	}
+}