Name every held kind of each module the flip takes in the converge preview and its digest (hq ADR 0103)

cmd/mesh-controller/adopting_test.go

@@ -168,7 +168,7 @@ func TestConvergingPreviewsThenChangesAndAdoptingKeepsWhatWasTaken(t *testing.T)
 		// The anchor faces inward and is on the private network: the derived filter admits ssh
 		// from the mesh only.
 		"WILL CLOSE to everything outside the private network — ssh stays open from the mesh",
-		"notes\n      replacing the found file /etc/notes.conf (original kept at",
+		"notes\n      replacing the found file /etc/notes.conf (notes.conf), original kept at",
 		"assigns nftables",
 		"the found firewall (ufw) is disabled, never flushed",
 		// What it routes is not a listener: said not to be previewed, and to be dropped.
@@ -431,3 +431,45 @@ func TestTheFlipHoldsTheNodeWhileItSends(t *testing.T) {
 	}
 	release()
 }
+
+// novox/hq ADR 0103: the preview names every kind of thing a module the flip takes holds as found,
+// not only its files, and the digest changes when any of them does.
+func TestThePreviewNamesEveryHeldKind(t *testing.T) {
+	open, _ := anAdoptedAnchor(t)
+	ctx := t.Context()
+	if _, err := take(ctx, open, "anchor", "hello-web"); err != nil {
+		t.Fatal(err)
+	}
+	since := time.Now()
+	held := []link.Held{heldFile,
+		{ID: "notes.data", Module: "notes", Kind: "directory", Target: "/var/lib/notes", Since: since},
+		{ID: "notes.daemon", Module: "notes", Kind: "service", Target: "notes.service", Since: since},
+		{ID: "notes.seed", Module: "notes", Kind: "archive", Target: "/srv/notes", Since: since},
+		{ID: "notes.worker", Module: "notes", Kind: "process", Target: "notes-worker", Since: since},
+		{ID: "notes.account", Module: "notes", Kind: "user", Target: "notes", Since: since},
+	}
+	reportsHolding(t, open, held...)
+	preview, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, want := range []string{
+		"replacing the found directory /var/lib/notes (notes.data)",
+		"replacing the found service notes.service (notes.daemon)",
+		"replacing the found archive /srv/notes (notes.seed)",
+		"replacing the found process notes-worker (notes.worker)",
+		"replacing the found user notes (notes.account)",
+	} {
+		if !strings.Contains(preview, want) {
+			t.Errorf("the preview does not say %q:\n%s", want, preview)
+		}
+	}
+	reportsHolding(t, open, held[:len(held)-1]...)
+	fewer, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if digestIn(t, fewer) == digestIn(t, preview) {
+		t.Fatal("the digest does not change with what is held")
+	}
+}

cmd/mesh-controller/adoption.go

@@ -119,7 +119,7 @@ func take(ctx context.Context, open *stores, node, module string) (string, error
 	var replaces []string
 	for _, h := range reported.Held {
 		if h.Module == module {
-			replaces = append(replaces, fmt.Sprintf("  %s %s (%s)", h.Kind, h.Target, h.ID))
+			replaces = append(replaces, "  "+heldLine(h))
 		}
 	}
 	if len(replaces) > 0 {
@@ -347,14 +347,18 @@ func previewOf(node string, reported inventory.Adoption, derived derivedFilter,
 	for _, m := range takes {
 		fmt.Fprintf(&b, "    %s\n", m)
 		said = append(said, "take "+m)
+		// Every kind it holds — a directory, a service, an archive, a process, a user as well as a
+		// file (novox/hq ADR 0103) — each said, and each part of what the flip is asked to act on.
 		for _, h := range reported.Held {
-			if h.Module == m && h.Kind == "file" {
-				fmt.Fprintf(&b, "      replacing the found file %s", h.Target)
-				if h.Kept != "" {
-					fmt.Fprintf(&b, " (original kept at %s)", h.Kept)
-				}
-				b.WriteString("\n")
+			if h.Module != m {
+				continue
 			}
+			fmt.Fprintf(&b, "      replacing the found %s", heldLine(h))
+			if h.Kept != "" {
+				fmt.Fprintf(&b, ", original kept at %s", h.Kept)
+			}
+			b.WriteString("\n")
+			said = append(said, "replace "+m+" "+heldLine(h)+" "+h.Kept)
 		}
 	}
 	if !filterAssigned {
@@ -427,6 +431,11 @@ func (d derivedFilter) fate(r inventory.Reach) string {
 	return "WILL CLOSE — no module assigned here declares it"
 }
 
+// heldLine is one thing a node holds as found, as take and the converge preview both say it.
+func heldLine(h inventory.Held) string {
+	return fmt.Sprintf("%s %s (%s)", h.Kind, h.Target, h.ID)
+}
+
 // loopback is an address nothing off the machine reaches.
 func loopback(address string) bool {
 	a := strings.Trim(address, "[]")