restic: keep a backup taken by hand past the next thinning, until a later night and keep-hand-taken-days, so the restore point taken against a risky change is still there when it is needed (novox/hq issue 453)

modules/restic/cmd/restic-backups/backups.go

@@ -8,7 +8,7 @@
 //	path <directory>      a directory the module's snapshot keeps
 //
 // Each module gets one snapshot a night, tagged with its name, so a module is listed, kept and
-// restored on its own. Everything lands in one repository on the machine — deduplicated, so every
+// restored on its own; one taken by hand is tagged as such too, and kept apart (hand.go). Everything lands in one repository on the machine — deduplicated, so every
 // night is a complete restore point and only what changed costs space — and is thinned by the machine's
 // settings keep-daily, keep-weekly and keep-monthly (retention.go). Against mistakes, not disasters:
 // nothing leaves the machine. How the last night and thinning went is the module's health (health.go).
@@ -277,7 +277,7 @@ func (b *Backups) ensureRepository(ctx context.Context) error {
 
 // one is one module's night: its run lines, then one snapshot of its paths. A failure is that
 // module's alone.
-func (b *Backups) one(ctx context.Context, d Declared) Night {
+func (b *Backups) one(ctx context.Context, d Declared, hand bool) Night {
 	n := Night{At: b.Now().UTC()}
 	fail := func(err error) Night {
 		n.Error = err.Error()
@@ -301,7 +301,11 @@ func (b *Backups) one(ctx context.Context, d Declared) Night {
 	if len(missing) > 0 {
 		return fail(fmt.Errorf("%s does not exist", strings.Join(missing, ", ")))
 	}
-	out, err := b.restic(ctx, append([]string{"backup", "--json", "--tag", tagOf(d.Module)}, d.Paths...)...)
+	args := []string{"backup", "--json", "--tag", tagOf(d.Module)}
+	if hand {
+		args = append(args, "--tag", HandTag)
+	}
+	out, err := b.restic(ctx, append(args, d.Paths...)...)
 	if err != nil {
 		return fail(err)
 	}
@@ -332,6 +336,11 @@ func snapshotOf(out string) string {
 // BackUp is a night: every module, or one, then the rotation. It answers each module's outcome, and
 // keeps how the night as a whole and its thinning went for the health (novox/hq issue 454).
 func (b *Backups) BackUp(ctx context.Context, only string) (map[string]Night, error) {
+	return b.backUp(ctx, only, false)
+}
+
+// backUp is a night, or a backup taken by hand (hand.go): the same but for the restore points' tag.
+func (b *Backups) backUp(ctx context.Context, only string, hand bool) (map[string]Night, error) {
 	run := b.LastRun()
 	run.At = b.Now().UTC()
 	failed := func(err error) (map[string]Night, error) {
@@ -368,7 +377,7 @@ func (b *Backups) BackUp(ctx context.Context, only string) (map[string]Night, er
 	}
 	outcome := map[string]Night{}
 	for _, d := range chosen {
-		outcome[d.Module] = b.one(ctx, d)
+		outcome[d.Module] = b.one(ctx, d, hand)
 		b.record(d.Module, outcome[d.Module])
 	}
 	// A retention that does not read thins nothing: keeping too much costs space, thinning by a value
@@ -378,18 +387,42 @@ func (b *Backups) BackUp(ctx context.Context, only string) (map[string]Night, er
 	if err != nil {
 		thinned.Refused = err.Error()
 		b.Say("the retention does not read, so nothing is thinned and every restore point is kept: %v", err)
-	} else if _, err := b.restic(ctx, "forget", "--prune", "--group-by", "host,tags",
-		"--keep-daily", fmt.Sprint(keep.Daily), "--keep-weekly", fmt.Sprint(keep.Weekly), "--keep-monthly", fmt.Sprint(keep.Monthly)); err != nil {
+	} else if letGo, err := b.thin(ctx, keep); err != nil {
 		thinned.Kept, thinned.Error = &keep, err.Error()
 		b.Say("thinning the restore points failed, and every one is kept: %v", err)
 	} else {
-		thinned.Kept, thinned.OK = &keep, true
+		thinned.Kept, thinned.OK, thinned.LetGo = &keep, true, letGo
 	}
 	run.Failed, run.Thinned = "", &thinned
 	b.keepRun(run)
 	return outcome, nil
 }
 
+// thin forgets the restore points taken by hand that are past their days and have a later night of their
+// module, by id, then thins the rest by the counts, keeping every one still tagged as taken by hand (novox/hq
+// issue 453). It answers the short ids it let go. A list that does not read thins nothing: a restore point
+// taken by hand is never lost to a list nobody could read.
+func (b *Backups) thin(ctx context.Context, keep Retention) ([]string, error) {
+	snaps, err := b.Snapshots(ctx, "")
+	if err != nil {
+		return nil, fmt.Errorf("the restore points could not be listed: %w", err)
+	}
+	var ids, letGo []string
+	for _, s := range handLetGo(snaps, b.Now(), keep.Hand) {
+		ids, letGo = append(ids, s.ID), append(letGo, s.ShortID)
+	}
+	if len(ids) > 0 {
+		if _, err := b.restic(ctx, append([]string{"forget"}, ids...)...); err != nil {
+			return nil, err
+		}
+		b.Say("let go the restore points taken by hand past %d days with a later night: %s", keep.Hand, strings.Join(letGo, ", "))
+	}
+	_, err = b.restic(ctx, "forget", "--prune", "--group-by", "host,tags",
+		"--keep-daily", fmt.Sprint(keep.Daily), "--keep-weekly", fmt.Sprint(keep.Weekly), "--keep-monthly", fmt.Sprint(keep.Monthly),
+		"--keep-tag", HandTag)
+	return letGo, err
+}
+
 // Run is how the last night, or backup asked for now, went as a whole: whether it ran at all, and its
 // thinning. Each module's own outcome is its Night.
 type Run struct {
@@ -406,6 +439,8 @@ type Thinning struct {
 	Kept    *Retention `json:"kept,omitempty"`
 	Refused string     `json:"refused,omitempty"`
 	Error   string     `json:"error,omitempty"`
+	// LetGo is the restore points taken by hand it forgot, past their days and with a later night (hand.go).
+	LetGo []string `json:"letGo,omitempty"`
 }
 
 func (b *Backups) runFile() string { return filepath.Join(b.Where.State, "run.json") }
@@ -469,6 +504,8 @@ type ModuleBackups struct {
 	// Data is every item the module declares, measured, with its newest good backup (novox/hq ADR
 	// 0233): what the controller's self-check reads.
 	Data []ItemReport `json:"data"`
+	// HandTaken is its restore points taken by hand, each with until when it is kept (novox/hq issue 453).
+	HandTaken []HandKept `json:"handTaken"`
 }
 
 // BackedUp is what is backed up here: each module, what it declared, its last night and its restore
@@ -496,7 +533,8 @@ func (b *Backups) BackedUp(ctx context.Context, module string) ([]ModuleBackups,
 		}
 		listed[d.Module] = true
 		m := ModuleBackups{Module: d.Module, Runs: len(d.Runs), Paths: d.Paths, Retention: inForce, Thinned: thinned,
-			Data: itemReports(items[d.Module], measured[d.Module], d.Paths, good[d.Module])}
+			Data:      itemReports(items[d.Module], measured[d.Module], d.Paths, good[d.Module]),
+			HandTaken: handKept(d.Module, snaps, inForce)}
 		if n, ok := nights[d.Module]; ok {
 			m.LastNight = &n
 		}
@@ -514,7 +552,7 @@ func (b *Backups) BackedUp(ctx context.Context, module string) ([]ModuleBackups,
 		if listed[name] || (module != "" && name != module) {
 			continue
 		}
-		out = append(out, ModuleBackups{Module: name, Paths: []string{}, Data: itemReports(its, measured[name], nil, time.Time{})})
+		out = append(out, ModuleBackups{Module: name, Paths: []string{}, HandTaken: []HandKept{}, Data: itemReports(its, measured[name], nil, time.Time{})})
 	}
 	return out, nil
 }

modules/restic/cmd/restic-backups/backups_test.go

@@ -26,7 +26,7 @@ func placed(t *testing.T, declared string) Where {
 	must(t, os.WriteFile(filepath.Join(dir, "backups.conf"), []byte(declared), 0o600))
 	must(t, os.WriteFile(filepath.Join(dir, "pw"), []byte("secret\n"), 0o600))
 	// The retention file every machine has, as the mesh writes it with the defaults (novox/hq issue 454).
-	must(t, os.WriteFile(filepath.Join(dir, RetentionFile), []byte("daily=14\nweekly=8\nmonthly=6\n"), 0o600))
+	must(t, os.WriteFile(filepath.Join(dir, RetentionFile), []byte("daily=14\nweekly=8\nmonthly=6\nhand=7\n"), 0o600))
 	return Where{Declared: filepath.Join(dir, "backups.conf"), Repository: filepath.Join(dir, "repo"),
 		PasswordFile: filepath.Join(dir, "pw"), State: dir}
 }
@@ -107,7 +107,8 @@ func TestANightDumpsBeforeEachSnapshotAndOneFailingModuleFailsOnlyItself(t *test
 		"restic backup --json --tag module=pg /",
 		"sh -c fail-it",
 		"restic backup --json --tag module=mail /",
-		"restic forget --prune --group-by host,tags --keep-daily 14 --keep-weekly 8 --keep-monthly 6",
+		"restic snapshots --json",
+		"restic forget --prune --group-by host,tags --keep-daily 14 --keep-weekly 8 --keep-monthly 6 --keep-tag hand",
 	}
 	if !reflect.DeepEqual(calls, want) {
 		t.Errorf("ran\n%s\nwant\n%s", strings.Join(calls, "\n"), strings.Join(want, "\n"))

modules/restic/cmd/restic-backups/hand.go

@@ -0,0 +1,108 @@
+package main
+
+// A backup taken by hand (novox/hq issue 453): `node-backup.now`, asked by a person before a risky change or by
+// the mesh before a module moves (ADR 0233, the bus's snapshot before its upgrade). The thinning after every
+// backup keeps only the newest restore point of each day, so one taken at 02:35 was forgotten by the night at
+// 03:01 — while the night's may already hold the damage it was taken against.
+//
+// So a backup taken by hand is tagged HandTag beside its module's tag, and is kept by restic's own --keep-tag:
+// with the thinning grouping by tags, it is its own group too, never counted against the nights. It is kept
+// until a later good night of its module exists, and for the machine's keep-hand-taken-days in any case; past
+// both, the thinning forgets it by its id (handLetGo). The nights are thinned by their counts alone: no rule
+// that keeps one keeps every night.
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"strings"
+	"time"
+)
+
+// HandTag marks a restore point taken by hand.
+const HandTag = "hand"
+
+// BackUpNow is a backup asked for now, of every module or one: as a night, each restore point tagged HandTag.
+func (b *Backups) BackUpNow(ctx context.Context, only string) (map[string]Night, error) {
+	return b.backUp(ctx, only, true)
+}
+
+// isHand is whether a restore point was taken by hand.
+func isHand(s Snapshot) bool { return slices.Contains(s.Tags, HandTag) }
+
+// moduleOf is the module a restore point is of; empty when it carries no module's tag.
+func moduleOf(s Snapshot) string {
+	for _, t := range s.Tags {
+		if m, ok := strings.CutPrefix(t, "module="); ok && m != "" {
+			return m
+		}
+	}
+	return ""
+}
+
+// isNight is whether a restore point is a night's: its module's tag and nothing else — neither taken by hand
+// nor a retired item's last one. Restic writes a snapshot only for a backup that succeeded, so each is good.
+func isNight(s Snapshot) bool { return len(s.Tags) == 1 && moduleOf(s) != "" }
+
+// latestNights is the time of each module's newest night.
+func latestNights(snaps []Snapshot) map[string]time.Time {
+	latest := map[string]time.Time{}
+	for _, s := range snaps {
+		if m := moduleOf(s); isNight(s) && s.Time.After(latest[m]) {
+			latest[m] = s.Time
+		}
+	}
+	return latest
+}
+
+// handLetGo is the restore points taken by hand that the thinning forgets: older than days, and with a night of
+// the same module after them. Every other one taken by hand is kept.
+func handLetGo(snaps []Snapshot, now time.Time, days int) []Snapshot {
+	latest := latestNights(snaps)
+	cutoff := now.AddDate(0, 0, -days)
+	var out []Snapshot
+	for _, s := range snaps {
+		if isHand(s) && s.Time.Before(cutoff) && latest[moduleOf(s)].After(s.Time) {
+			out = append(out, s)
+		}
+	}
+	return out
+}
+
+// HandKept is one restore point taken by hand, as `backed-up` says it.
+type HandKept struct {
+	Snapshot string    `json:"snapshot"`
+	At       time.Time `json:"at"`
+	// KeptAtLeastUntil is when its days are up; WaitsForANight that no later good night of its module exists
+	// yet, and it is kept until one does as well. The first thinning after both forgets it.
+	KeptAtLeastUntil time.Time `json:"keptAtLeastUntil"`
+	WaitsForANight   bool      `json:"waitsForANight"`
+	Kept             string    `json:"kept"`
+}
+
+// handKept is a module's restore points taken by hand, oldest first, said with the retention in force.
+func handKept(module string, snaps []Snapshot, keep InForce) []HandKept {
+	latest := latestNights(snaps)
+	out := []HandKept{}
+	for _, s := range snaps {
+		if !isHand(s) || moduleOf(s) != module {
+			continue
+		}
+		k := HandKept{Snapshot: s.ShortID, At: s.Time, WaitsForANight: !latest[module].After(s.Time)}
+		switch {
+		case keep.Retention == nil:
+			k.Kept = "kept: nothing is thinned while the retention is refused"
+		case k.WaitsForANight:
+			k.KeptAtLeastUntil = s.Time.AddDate(0, 0, keep.Hand)
+			k.Kept = fmt.Sprintf("kept as taken by hand until a later good night of %s exists, and at least until %s",
+				module, k.KeptAtLeastUntil.UTC().Format(time.RFC3339))
+		default:
+			k.KeptAtLeastUntil = s.Time.AddDate(0, 0, keep.Hand)
+			k.Kept = fmt.Sprintf("kept as taken by hand until %s; the first thinning after forgets it",
+				k.KeptAtLeastUntil.UTC().Format(time.RFC3339))
+		}
+		out = append(out, k)
+	}
+	slices.SortFunc(out, func(a, b HandKept) int { return a.At.Compare(b.At) })
+	return out
+}

modules/restic/cmd/restic-backups/hand_test.go

@@ -0,0 +1,256 @@
+package main
+
+// A backup taken by hand — `node-backup.now`, asked by a person or by the mesh before a module moves (novox/hq
+// ADR 0233) — is kept by the thinning as its own restore point: until a later good night of the same module
+// exists, and for the machine's keep-hand-taken-days in any case (novox/hq issue 453: one taken at 02:35 was
+// forgotten by the night at 03:01, as keep-daily keeps only the newest restore point of each day).
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"slices"
+	"strings"
+	"testing"
+	"time"
+)
+
+// handRestic is a fake restic that remembers each command and lists the snapshots it is given.
+type handRestic struct {
+	calls []string
+	snaps []Snapshot
+}
+
+func (h *handRestic) run(_ context.Context, name string, args ...string) (string, error) {
+	if name != "restic" {
+		return "", nil
+	}
+	line := "restic " + strings.Join(args[5:], " ")
+	h.calls = append(h.calls, line)
+	switch args[5] {
+	case "backup":
+		return "{\"message_type\":\"summary\",\"snapshot_id\":\"abcdef0123456789\"}\n", nil
+	case "snapshots":
+		raw, _ := json.Marshal(h.snaps)
+		return string(raw), nil
+	}
+	return "", nil
+}
+
+func (h *handRestic) with(prefix string) []string {
+	var out []string
+	for _, c := range h.calls {
+		if strings.HasPrefix(c, prefix) {
+			out = append(out, c)
+		}
+	}
+	return out
+}
+
+func TestAHandTakenBackupIsTaggedAndTheThinningKeepsThatTag(t *testing.T) {
+	h := &handRestic{}
+	b := &Backups{Where: placed(t, "# pg\npath /\n"), Run: h.run,
+		Now: func() time.Time { return time.Date(2026, 10, 11, 2, 35, 0, 0, time.UTC) }, Say: quiet}
+	_, err := b.BackUpNow(context.Background(), "pg")
+	must(t, err)
+	if got := h.with("restic backup"); len(got) != 1 || got[0] != "restic backup --json --tag module=pg --tag hand /" {
+		t.Errorf("backed up by hand with %q, want it tagged hand", got)
+	}
+	_, err = b.BackUp(context.Background(), "")
+	must(t, err)
+	if got := h.with("restic backup"); len(got) != 2 || got[1] != "restic backup --json --tag module=pg /" {
+		t.Errorf("the night backed up with %q, want it tagged with its module alone", got)
+	}
+	want := "restic forget --prune --group-by host,tags --keep-daily 14 --keep-weekly 8 --keep-monthly 6 --keep-tag hand"
+	for _, f := range h.with("restic forget") {
+		if f != want {
+			t.Errorf("thinned with %q, want %q", f, want)
+		}
+		// No rule that would keep every night as well: the hand tag is the only thing kept beyond the counts.
+		if strings.Contains(f, "--keep-within") || strings.Contains(f, "--keep-last") {
+			t.Errorf("thinned with %q, a rule that keeps nights too", f)
+		}
+	}
+	if len(h.with("restic forget")) != 2 {
+		t.Errorf("thinned %d times, want after each of the two backups", len(h.with("restic forget")))
+	}
+}
+
+func TestAHandTakenRestorePointIsLetGoOnlyPastItsBoundAndAfterALaterNight(t *testing.T) {
+	now := time.Date(2026, 10, 20, 3, 0, 0, 0, time.UTC)
+	at := func(days float64) time.Time { return now.Add(-time.Duration(days * 24 * float64(time.Hour))) }
+	snap := func(id string, when time.Time, tags ...string) Snapshot {
+		return Snapshot{ID: id + "0000000000", ShortID: id, Time: when, Tags: tags}
+	}
+	snaps := []Snapshot{
+		snap("oldhand1", at(10), "module=pg", HandTag),   // past the bound, a night after it: let go
+		snap("night001", at(9), "module=pg"),             // the night after it
+		snap("freshhnd", at(2), "module=pg", HandTag),    // within the bound: kept
+		snap("lonehand", at(12), "module=mail", HandTag), // past the bound, no night of mail after it: kept
+		snap("mailnite", at(13), "module=mail"),          // a night of mail, but before it
+		snap("pghand02", at(8.5), "module=pg", HandTag),  // past the bound, night001 is before it, but a night of
+		snap("pgnight2", at(1), "module=pg"),             // pg after it exists: let go
+		snap("retired1", at(30), "module=pg", "retired=data"),
+		snap("otherhnd", at(11), "module=web", HandTag),          // a night of another module after it is no night of its own
+		snap("ret-hand", at(11), "module=web", "retired=x"),      // a retired restore point is no night either
+		snap("webnight", at(10.5), "module=web", "retired=data"), // nor this
+	}
+	got := handLetGo(snaps, now, 7)
+	var ids []string
+	for _, s := range got {
+		ids = append(ids, s.ShortID)
+	}
+	slices.Sort(ids)
+	if want := []string{"oldhand1", "pghand02"}; !slices.Equal(ids, want) {
+		t.Errorf("let go %v, want %v", ids, want)
+	}
+}
+
+// The thinning forgets a hand-taken restore point past its bound by its id, and records which.
+func TestTheThinningForgetsAnExpiredHandTakenRestorePointByItsId(t *testing.T) {
+	now := time.Date(2026, 10, 20, 3, 0, 0, 0, time.UTC)
+	h := &handRestic{snaps: []Snapshot{
+		{ID: "aaaaaaaa11", ShortID: "aaaaaaaa", Time: now.AddDate(0, 0, -9), Tags: []string{"module=pg", HandTag}},
+		{ID: "bbbbbbbb11", ShortID: "bbbbbbbb", Time: now, Tags: []string{"module=pg"}},
+	}}
+	b := &Backups{Where: placed(t, "# pg\npath /\n"), Run: h.run, Now: func() time.Time { return now }, Say: quiet}
+	_, err := b.BackUp(context.Background(), "")
+	must(t, err)
+	forgets := h.with("restic forget")
+	if len(forgets) != 2 || forgets[0] != "restic forget aaaaaaaa11" || !strings.HasPrefix(forgets[1], "restic forget --prune") {
+		t.Fatalf("thinned with %q, want the expired one forgotten by id, then the rotation", forgets)
+	}
+	th := b.LastRun().Thinned
+	if th == nil || !th.OK || !slices.Equal(th.LetGo, []string{"aaaaaaaa"}) {
+		t.Errorf("recorded %+v, want aaaaaaaa let go", th)
+	}
+}
+
+// When the restore points cannot be listed, nothing is thinned: a hand-taken one is never lost to a list
+// that did not read.
+func TestARestorePointListThatFailsThinsNothing(t *testing.T) {
+	var forgot []string
+	run := func(_ context.Context, name string, args ...string) (string, error) {
+		if name != "restic" {
+			return "", nil
+		}
+		switch args[5] {
+		case "backup":
+			return "{\"message_type\":\"summary\",\"snapshot_id\":\"abcdef0123456789\"}\n", nil
+		case "snapshots":
+			return "", errors.New("Fatal: repository is already locked")
+		case "forget":
+			forgot = append(forgot, strings.Join(args[5:], " "))
+		}
+		return "", nil
+	}
+	b := &Backups{Where: placed(t, "# pg\npath /\n"), Run: run, Now: time.Now, Say: quiet}
+	_, err := b.BackUp(context.Background(), "")
+	must(t, err)
+	if len(forgot) != 0 {
+		t.Errorf("thinned with %q", forgot)
+	}
+	if th := b.LastRun().Thinned; th == nil || th.OK || !strings.Contains(th.Error, "already locked") {
+		t.Errorf("recorded %+v, want the failure", th)
+	}
+}
+
+// backed-up says each hand-taken restore point and until when it is kept.
+func TestBackedUpSaysWhichRestorePointsAreKeptAsHandTakenAndUntilWhen(t *testing.T) {
+	now := time.Date(2026, 10, 11, 12, 0, 0, 0, time.UTC)
+	early, late := now.Add(-10*time.Hour), now.Add(-time.Hour)
+	h := &handRestic{snaps: []Snapshot{
+		{ID: "aaaaaaaa11", ShortID: "aaaaaaaa", Time: early, Tags: []string{"module=pg", HandTag}},
+		{ID: "bbbbbbbb11", ShortID: "bbbbbbbb", Time: now.Add(-5 * time.Hour), Tags: []string{"module=pg"}},
+		{ID: "cccccccc11", ShortID: "cccccccc", Time: late, Tags: []string{"module=pg", HandTag}},
+	}}
+	b := &Backups{Where: placed(t, "# pg\npath /\n"), Run: h.run, Now: func() time.Time { return now }, Say: quiet}
+	listed, err := b.BackedUp(context.Background(), "pg")
+	must(t, err)
+	if len(listed) != 1 || len(listed[0].HandTaken) != 2 {
+		t.Fatalf("listed %+v, want pg with two hand-taken restore points", listed)
+	}
+	first, second := listed[0].HandTaken[0], listed[0].HandTaken[1]
+	if first.Snapshot != "aaaaaaaa" || !first.KeptAtLeastUntil.Equal(early.AddDate(0, 0, 7)) || first.WaitsForANight {
+		t.Errorf("the first: %+v, want kept until 7 days after it, a night of pg after it already there", first)
+	}
+	if second.Snapshot != "cccccccc" || !second.KeptAtLeastUntil.Equal(late.AddDate(0, 0, 7)) || !second.WaitsForANight {
+		t.Errorf("the second: %+v, want kept at least 7 days and until a later night", second)
+	}
+	if !strings.Contains(second.Kept, "a later good night of pg") || !strings.Contains(first.Kept, early.AddDate(0, 0, 7).Format(time.RFC3339)) {
+		t.Errorf("said %q and %q", first.Kept, second.Kept)
+	}
+}
+
+// The real thing, where restic is installed: the issue as it was seen — a backup taken by hand, then a night
+// the same day — and the hand-taken restore point is still there; a week and a day later, with a later night
+// of its module, the thinning lets it go.
+func TestWithTheRealResticAHandTakenBackupOutlivesTheNightTheSameDay(t *testing.T) {
+	if _, err := exec.LookPath("restic"); err != nil {
+		t.Skip("restic is not installed")
+	}
+	root := t.TempDir()
+	data := filepath.Join(root, "data")
+	must(t, os.Mkdir(data, 0o700))
+	must(t, os.WriteFile(filepath.Join(data, "library"), []byte("before the migration\n"), 0o600))
+	where := placed(t, "# plex\npath "+data+"\n")
+	// A machine whose counts are full, as ace's plex was: restic keeps the oldest restore point of a period not
+	// yet filled, which would hide the issue on a fresh repository.
+	conf, err := os.ReadFile(filepath.Join(where.State, RetentionFile))
+	must(t, err)
+	must(t, os.WriteFile(filepath.Join(where.State, RetentionFile),
+		[]byte(strings.Replace(string(conf), "daily=14\nweekly=8\nmonthly=6", "daily=1\nweekly=1\nmonthly=1", 1)), 0o600))
+	// As in the other real test: the directories above the test's own are said to be root's, so the restore
+	// beside is what is tested.
+	run := func(ctx context.Context, name string, args ...string) (string, error) {
+		if name == "stat" && len(args) > 0 && strings.HasPrefix(root, strings.TrimSuffix(args[len(args)-1], "/")+"/") {
+			return "0 755 directory\n", nil
+		}
+		out, err := exec.CommandContext(ctx, name, args...).Output()
+		if ee, ok := err.(*exec.ExitError); ok {
+			return string(out), errors.New(string(ee.Stderr))
+		}
+		return string(out), err
+	}
+	clock := time.Now()
+	b := &Backups{Where: where, Run: run, Now: func() time.Time { return clock }, Say: quiet}
+	ctx := context.Background()
+
+	hand, err := b.BackUpNow(ctx, "plex")
+	must(t, err)
+	must(t, os.WriteFile(filepath.Join(data, "library"), []byte("the damage\n"), 0o600))
+	night, err := b.BackUp(ctx, "")
+	must(t, err)
+	if !hand["plex"].OK || !night["plex"].OK {
+		t.Fatalf("hand %+v, night %+v", hand, night)
+	}
+	listed, err := b.BackedUp(ctx, "plex")
+	must(t, err)
+	if listed[0].RestorePoints != 2 {
+		t.Fatalf("%d restore points after the night, want the hand-taken one kept beside the night's", listed[0].RestorePoints)
+	}
+	if len(listed[0].HandTaken) != 1 || listed[0].HandTaken[0].Snapshot != hand["plex"].Snapshot {
+		t.Fatalf("hand-taken %+v, want %s", listed[0].HandTaken, hand["plex"].Snapshot)
+	}
+	r, err := b.Restore(ctx, "plex", hand["plex"].Snapshot, "")
+	must(t, err)
+	if raw, _ := os.ReadFile(filepath.Join(r.Restored[0], "library")); string(raw) != "before the migration\n" {
+		t.Errorf("the hand-taken restore point holds %q", raw)
+	}
+
+	// Eight days on, a night of plex later than it exists: the thinning lets it go.
+	clock = clock.AddDate(0, 0, 8)
+	_, err = b.BackUp(ctx, "")
+	must(t, err)
+	listed, err = b.BackedUp(ctx, "plex")
+	must(t, err)
+	if len(listed[0].HandTaken) != 0 {
+		t.Errorf("hand-taken %+v eight days on, want it let go", listed[0].HandTaken)
+	}
+	if th := b.LastRun().Thinned; th == nil || !slices.Equal(th.LetGo, []string{hand["plex"].Snapshot}) {
+		t.Errorf("recorded %+v, want the hand-taken restore point let go", th)
+	}
+}

modules/restic/cmd/restic-backups/health.go

@@ -113,8 +113,8 @@ func Judge(s Seen) Health {
 	r := s.Retention
 	switch {
 	case r.Refused == "" && r.Retention != nil:
-		said = append(said, fmt.Sprintf("The next thinning keeps %d daily, %d weekly and %d monthly restore points of each module.",
-			r.Daily, r.Weekly, r.Monthly))
+		said = append(said, fmt.Sprintf("The next thinning keeps %d daily, %d weekly and %d monthly restore points of each module, "+
+			"and each taken by hand until a later good night and %d days at least.", r.Daily, r.Weekly, r.Monthly, r.Hand))
 	case r.Setting != "":
 		value := "not set"
 		if r.Value != "" {
@@ -138,7 +138,7 @@ func Judge(s Seen) Health {
 	case strings.Contains(r.Refused, RetentionFile+": "):
 		// Read, and not in the form the mesh writes: something other than the mesh wrote it.
 		found = append(found, fmt.Sprintf("The retention is refused: %s; nothing is thinned and every restore point is "+
-			"kept, so the repository grows. The mesh writes only daily=, weekly= and monthly=, so something else wrote "+
+			"kept, so the repository grows. The mesh writes only daily=, weekly=, monthly= and hand=, so something else wrote "+
 			"this file; push this machine (mesh-controller.push) so the mesh writes it again.", r.Refused))
 	default:
 		found = append(found, fmt.Sprintf("The retention is refused: %s; nothing is thinned and every restore point is "+
@@ -173,8 +173,8 @@ func healthySaid(s Seen, said []string) string {
 	case t == nil:
 		parts = append(parts, "No thinning is recorded yet.")
 	case t.OK && t.Kept != nil:
-		parts = append(parts, fmt.Sprintf("The last thinning, at %s, kept %d daily, %d weekly and %d monthly restore points.",
-			clock(t.At), t.Kept.Daily, t.Kept.Weekly, t.Kept.Monthly))
+		parts = append(parts, fmt.Sprintf("The last thinning, at %s, kept %d daily, %d weekly and %d monthly restore points%s.",
+			clock(t.At), t.Kept.Daily, t.Kept.Weekly, t.Kept.Monthly, letGoSaid(t.LetGo)))
 	case t.Refused != "":
 		parts = append(parts, fmt.Sprintf("The last thinning, at %s, thinned nothing: its retention was refused then.", clock(t.At)))
 	}
@@ -187,3 +187,11 @@ func (b *Backups) Health(ctx context.Context) Health {
 	return Judge(Seen{Declared: declared, DeclaredErr: err, Nights: b.Nights(), Good: b.Good(), Run: b.LastRun(),
 		Retention: b.inForce(ctx), Awake: b.LastAwake(), Now: b.Now()})
 }
+
+// letGoSaid is the restore points taken by hand a thinning let go, as the health says them (novox/hq issue 453).
+func letGoSaid(ids []string) string {
+	if len(ids) == 0 {
+		return ""
+	}
+	return ", and let go " + strings.Join(ids, ", ") + ", taken by hand, past their days and a later night"
+}

modules/restic/cmd/restic-backups/health_test.go

@@ -363,7 +363,7 @@ func TestAHealthyAnswerSaysOnlyWhatWasSeen(t *testing.T) {
 	if h := Judge(seen); !strings.Contains(h.Why, "thinned nothing") || strings.Contains(h.Why, "kept 14") {
 		t.Fatalf("after a refused thinning: %q", h.Why)
 	}
-	seen.Run.Thinned = &Thinning{At: good, OK: true, Kept: &Retention{7, 4, 24}}
+	seen.Run.Thinned = &Thinning{At: good, OK: true, Kept: &Retention{7, 4, 24, 10}}
 	if h := Judge(seen); !strings.Contains(h.Why, "kept 7 daily, 4 weekly and 24 monthly") {
 		t.Fatalf("after a thinning: %q", h.Why)
 	}

modules/restic/cmd/restic-backups/main.go

@@ -148,13 +148,13 @@ func tools(b *Backups) []stdio.Tool {
 		verb("backed-up", "What this machine backs up: each module, what it declared, its last good night, how many restore points are kept.",
 			map[string]any{"module": str("one module (optional)")},
 			func(a map[string]any) (any, error) { return b.BackedUp(context.Background(), arg(a, "module")) }),
-		verb("now", "Take a backup now, of one module or of every module on this machine — before a migration, a retirement or anything else that could go wrong. Answers when it has started; `backed-up` says how it went.",
+		verb("now", "Take a backup now, of one module or of every module on this machine — before a migration, a retirement or anything else that could go wrong. Kept as taken by hand until a later good night of the module exists, and for keep-hand-taken-days in any case. Answers when it has started; `backed-up` says how it went.",
 			map[string]any{"module": str("one module (optional)")},
 			func(a map[string]any) (any, error) {
 				only := arg(a, "module")
 				// A night of a large store outlasts any call; it is started, and its outcome recorded.
 				go func() {
-					if _, err := b.BackUp(context.Background(), only); err != nil {
+					if _, err := b.BackUpNow(context.Background(), only); err != nil {
 						say("a backup asked for now failed: %v", err)
 					}
 				}()

modules/restic/cmd/restic-backups/retention.go

@@ -1,7 +1,7 @@
 package main
 
 // The retention as a preference (novox/hq issue 416, ADR 0262). The mesh writes the settings
-// keep-daily, keep-weekly and keep-monthly into RetentionFile in this module's state, each defaulting
+// keep-daily, keep-weekly and keep-monthly, and keep-hand-taken-days (novox/hq issue 453), into RetentionFile in this module's state, each defaulting
 // to today's rotation, so a machine that sets none thins exactly as before. The controller does not
 // type a setting yet (ADR 0164 is proposed), so this program is where a bad value is caught: it is
 // refused here and never handed to restic (issue 346: a raw setting is an injection point).
@@ -18,16 +18,19 @@ import (
 	"strings"
 )
 
-// Retention is how many restore points each period keeps.
+// Retention is how many restore points each period keeps, and how many days a restore point taken by hand is
+// kept at least (hand.go).
 type Retention struct {
 	Daily   int `json:"daily"`
 	Weekly  int `json:"weekly"`
 	Monthly int `json:"monthly"`
+	Hand    int `json:"handDays"`
 }
 
 // TodaysRetention is the rotation before it was a preference (novox/hq ADR 0214), and still the
-// manifest's default — never a fallback for a file that is not there (novox/hq issue 454).
-var TodaysRetention = Retention{14, 8, 6}
+// manifest's default — never a fallback for a file that is not there (novox/hq issue 454). A restore point
+// taken by hand is kept a week at least: long enough to notice what a change broke (novox/hq issue 453).
+var TodaysRetention = Retention{14, 8, 6, 7}
 
 // RetentionFile is the file the mesh writes the retention into, in this module's state.
 const RetentionFile = "retention.conf"
@@ -36,10 +39,11 @@ const RetentionFile = "retention.conf"
 // past four digits is a typo, not a policy.
 var count = regexp.MustCompile(`^[1-9][0-9]{0,3}$`)
 
-// ParseRetention reads daily=, weekly= and monthly=, each once and each a count; anything else is
+// ParseRetention reads daily=, weekly=, monthly= and hand=, each once and each a count; anything else is
 // refused naming the setting it came from.
 func ParseRetention(text string) (Retention, error) {
-	settingOf := map[string]string{"daily": "keep-daily", "weekly": "keep-weekly", "monthly": "keep-monthly"}
+	settingOf := map[string]string{"daily": "keep-daily", "weekly": "keep-weekly", "monthly": "keep-monthly",
+		"hand": "keep-hand-taken-days"}
 	seen := map[string]int{}
 	for _, l := range strings.Split(text, "\n") {
 		l = strings.TrimSpace(l)
@@ -54,7 +58,7 @@ func ParseRetention(text string) (Retention, error) {
 		setting, known := settingOf[k]
 		switch {
 		case !known:
-			return Retention{}, fmt.Errorf("%q is no retention this module reads (daily, weekly, monthly)", k)
+			return Retention{}, fmt.Errorf("%q is no retention this module reads (daily, weekly, monthly, hand)", k)
 		case seen[k] != 0:
 			return Retention{}, fmt.Errorf("%s is given twice", k)
 		case !count.MatchString(v):
@@ -62,12 +66,12 @@ func ParseRetention(text string) (Retention, error) {
 		}
 		seen[k], _ = strconv.Atoi(v)
 	}
-	for _, k := range []string{"daily", "weekly", "monthly"} {
+	for _, k := range []string{"daily", "weekly", "monthly", "hand"} {
 		if seen[k] == 0 {
 			return Retention{}, &SettingRefused{Setting: settingOf[k]}
 		}
 	}
-	return Retention{seen["daily"], seen["weekly"], seen["monthly"]}, nil
+	return Retention{seen["daily"], seen["weekly"], seen["monthly"], seen["hand"]}, nil
 }
 
 // SettingRefused is one retention setting the night refuses: the operator's to give again.

modules/restic/cmd/restic-backups/retention_test.go

@@ -49,9 +49,9 @@ func thinning(t *testing.T, retention *string) (string, []string) {
 }
 
 func TestANightThinsByTheRetentionTheMeshWrote(t *testing.T) {
-	conf := "# Written by the mesh.\ndaily=7\nweekly=4\nmonthly=24\n"
+	conf := "# Written by the mesh.\ndaily=7\nweekly=4\nmonthly=24\nhand=10\n"
 	got, _ := thinning(t, &conf)
-	if want := "restic forget --prune --group-by host,tags --keep-daily 7 --keep-weekly 4 --keep-monthly 24"; got != want {
+	if want := "restic forget --prune --group-by host,tags --keep-daily 7 --keep-weekly 4 --keep-monthly 24 --keep-tag hand"; got != want {
 		t.Errorf("ran %q, want %q", got, want)
 	}
 }
@@ -145,6 +145,8 @@ func TestARetentionThatIsNotACountThinsNothingAndSaysWhich(t *testing.T) {
 		{"daily=14\nweekly=8\nmonthly=6\nlast=1\n", "last"},
 		{"daily=14\ndaily=3\nweekly=8\nmonthly=6\n", "daily"},
 		{"daily 14\nweekly=8\nmonthly=6\n", "key=value"},
+		{"daily=14\nweekly=8\nmonthly=6\nhand=0\n", "keep-hand-taken-days"},
+		{"daily=14\nweekly=8\nmonthly=6\n", "keep-hand-taken-days"},
 	} {
 		got, said := thinning(t, &c.conf)
 		if got != "" {
@@ -171,7 +173,7 @@ func TestTheManifestsDefaultsAreTodaysRetention(t *testing.T) {
 		Resources []map[string]any `json:"resources"`
 	}
 	must(t, json.Unmarshal(raw, &m))
-	want := map[string]float64{"keep-daily": 14, "keep-weekly": 8, "keep-monthly": 6}
+	want := map[string]float64{"keep-daily": 14, "keep-weekly": 8, "keep-monthly": 6, "keep-hand-taken-days": 7}
 	for k, v := range want {
 		s, ok := m.Settings[k]
 		if !ok || s.Kind != "preference" || s.Default != v || s.Why == "" {

modules/restic/module.json

@@ -52,6 +52,11 @@
       "kind": "preference",
       "default": 6,
       "why": "half a year of monthly restore points behind the weeklies; a count from 1 to 9999, refused by the night like keep-daily; lowering it deletes the restore points beyond the new count at the next night, and that cannot be undone"
+    },
+    "keep-hand-taken-days": {
+      "kind": "preference",
+      "default": 7,
+      "why": "a restore point taken by hand (node-backup.now, or the mesh's before a module moves) is kept until a later good night of its module exists, and this many days in any case, so the next thinning never takes the one taken against a risky change (novox/hq issue 453); a count from 1 to 9999, refused by the night like keep-daily; lowering it lets go of the restore points taken by hand that are older than the new count, past a later night, at the next thinning, and that cannot be undone"
     }
   },
   "resources": [
@@ -86,7 +91,7 @@
       "path": "${dir:state}/retention.conf",
       "mode": "0644",
       "trusted": true,
-      "content": "# How many restore points the night keeps, written by the mesh from this machine's settings keep-daily,\n# keep-weekly and keep-monthly (novox/hq issue 416). Replaced on every push; change the settings, never this file.\ndaily=${setting:keep-daily}\nweekly=${setting:keep-weekly}\nmonthly=${setting:keep-monthly}\n"
+      "content": "# How many restore points the night keeps, written by the mesh from this machine's settings keep-daily,\n# keep-weekly, keep-monthly (novox/hq issue 416) and keep-hand-taken-days (novox/hq issue 453). Replaced on every push; change the settings, never this file.\ndaily=${setting:keep-daily}\nweekly=${setting:keep-weekly}\nmonthly=${setting:keep-monthly}\nhand=${setting:keep-hand-taken-days}\n"
     },
     {
       "id": "tool",