slice 8B (controller half): app-consistent backup quiesce loop (v0.36.0)

internal/quiesce: poll /backup/due -> quiesce (stop app stacks) -> POST /backup
-> poll /backup/status -> unquiesce (restart exactly those). Crash-safety:
persisted marker before stopping, guaranteed unquiesce (defer), max-quiesce
guard, startup Recover, single-flight. agentapi BackupDue/StartBackup/
BackupStatus; stacks.RunningAppStacks(); config QuiesceConfig; main wiring.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
2026-06-10 10:44:52 +02:00
parent 10685b771c
commit 68fc153d9c
7 changed files with 813 additions and 0 deletions
+302
View File
@@ -0,0 +1,302 @@
package quiesce
import (
"context"
"io"
"log"
"os"
"path/filepath"
"sync"
"testing"
"time"
)
// fakeStacks records stop/start calls in order.
type fakeStacks struct {
mu sync.Mutex
running []string
stopped []string
started []string
stopErr map[string]error
}
func (f *fakeStacks) RunningAppStacks() []string {
f.mu.Lock()
defer f.mu.Unlock()
return append([]string(nil), f.running...)
}
func (f *fakeStacks) StopStack(name string) error {
f.mu.Lock()
defer f.mu.Unlock()
f.stopped = append(f.stopped, name)
if f.stopErr != nil {
return f.stopErr[name]
}
return nil
}
func (f *fakeStacks) StartStack(name string) error {
f.mu.Lock()
defer f.mu.Unlock()
f.started = append(f.started, name)
return nil
}
func (f *fakeStacks) startedNames() []string {
f.mu.Lock()
defer f.mu.Unlock()
return append([]string(nil), f.started...)
}
func (f *fakeStacks) stoppedNames() []string {
f.mu.Lock()
defer f.mu.Unlock()
return append([]string(nil), f.stopped...)
}
// fakeBackend drives the agent-side responses.
type fakeBackend struct {
due bool
dueErr error
startErr error
jobID string
phases []string // returned in sequence by BackupStatus; last value repeats
statusErr error
startCalls int
statusCalls int
mu sync.Mutex
}
func (b *fakeBackend) Due(context.Context) (bool, error) { return b.due, b.dueErr }
func (b *fakeBackend) StartBackup(context.Context) (string, error) {
b.mu.Lock()
b.startCalls++
b.mu.Unlock()
if b.startErr != nil {
return "", b.startErr
}
if b.jobID == "" {
b.jobID = "job-1"
}
return b.jobID, nil
}
func (b *fakeBackend) BackupStatus(context.Context) (string, error) {
if b.statusErr != nil {
return "", b.statusErr
}
b.mu.Lock()
defer b.mu.Unlock()
i := b.statusCalls
b.statusCalls++
if i >= len(b.phases) {
if len(b.phases) == 0 {
return PhaseRunning, nil
}
return b.phases[len(b.phases)-1], nil
}
return b.phases[i], nil
}
const PhaseRunning = "running" // local alias for readability in tests
func testLoop(t *testing.T, be Backend, st Stacks) *Loop {
t.Helper()
l := New(Options{
Backend: be,
Stacks: st,
MarkerPath: filepath.Join(t.TempDir(), "quiesce-state.json"),
Poll: time.Hour,
StatusPoll: time.Millisecond,
MaxQuiesce: 5 * time.Second,
Logger: log.New(io.Discard, "", 0),
})
return l
}
// Happy path: due → stop running stacks → start backup → poll to done → restart exactly those → clear marker.
func TestRunOnce_HappyPath(t *testing.T) {
be := &fakeBackend{due: true, phases: []string{"running", "running", "done"}}
st := &fakeStacks{running: []string{"nextcloud", "vaultwarden"}}
l := testLoop(t, be, st)
if err := l.runOnce(context.Background()); err != nil {
t.Fatalf("runOnce: %v", err)
}
if got := st.stoppedNames(); len(got) != 2 || got[0] != "nextcloud" || got[1] != "vaultwarden" {
t.Fatalf("stopped wrong/order: %v", got)
}
if got := st.startedNames(); len(got) != 2 || got[0] != "nextcloud" || got[1] != "vaultwarden" {
t.Fatalf("started wrong/order: %v", got)
}
if be.startCalls != 1 {
t.Fatalf("expected 1 backup, got %d", be.startCalls)
}
if _, ok := l.readMarker(); ok {
t.Fatal("marker not cleared after a successful cycle")
}
}
// Not due → nothing happens.
func TestRunOnce_NotDue(t *testing.T) {
be := &fakeBackend{due: false}
st := &fakeStacks{running: []string{"a"}}
l := testLoop(t, be, st)
if err := l.runOnce(context.Background()); err != nil {
t.Fatal(err)
}
if len(st.stoppedNames()) != 0 || be.startCalls != 0 {
t.Fatal("acted while not due")
}
}
// Backup START fails → stacks STILL restarted (guaranteed unquiesce).
func TestRunOnce_BackupStartFails_StillRestarts(t *testing.T) {
be := &fakeBackend{due: true, startErr: errString("boom")}
st := &fakeStacks{running: []string{"a", "b"}}
l := testLoop(t, be, st)
_ = l.runOnce(context.Background())
if got := st.startedNames(); len(got) != 2 {
t.Fatalf("stacks not restarted after a backup-start failure: %v", got)
}
if _, ok := l.readMarker(); ok {
t.Fatal("marker not cleared after a failed backup")
}
}
// Backup reports failed → stacks restarted.
func TestRunOnce_BackupFailedPhase_Restarts(t *testing.T) {
be := &fakeBackend{due: true, phases: []string{"running", "failed"}}
st := &fakeStacks{running: []string{"a"}}
l := testLoop(t, be, st)
_ = l.runOnce(context.Background())
if got := st.startedNames(); len(got) != 1 || got[0] != "a" {
t.Fatalf("not restarted after failed phase: %v", got)
}
}
// Max-quiesce guard: status never reaches done → stacks restarted at the bound.
func TestRunOnce_MaxQuiesceGuard(t *testing.T) {
be := &fakeBackend{due: true, phases: []string{"running"}} // never done
st := &fakeStacks{running: []string{"a", "b"}}
l := testLoop(t, be, st)
// shrink the bound + use a controllable clock so the guard fires fast
base := time.Now()
steps := 0
l.now = func() time.Time {
steps++
return base.Add(time.Duration(steps) * time.Minute) // each call advances 1m
}
l.maxQuiesce = 2 * time.Minute
done := make(chan error, 1)
go func() { done <- l.runOnce(context.Background()) }()
select {
case err := <-done:
if err != nil {
t.Fatalf("runOnce returned error: %v", err)
}
case <-time.After(2 * time.Second):
t.Fatal("runOnce did not return — max-quiesce guard did not fire")
}
if got := st.startedNames(); len(got) != 2 {
t.Fatalf("stacks not restarted at the max-quiesce bound: %v", got)
}
if _, ok := l.readMarker(); ok {
t.Fatal("marker not cleared after the guard fired")
}
}
// Crash recovery: a marker present at startup → recorded stacks restarted, marker cleared.
func TestRecover_RestartsFromMarker(t *testing.T) {
st := &fakeStacks{}
l := testLoop(t, &fakeBackend{}, st)
// simulate a crash mid-quiesce: an active marker with stopped stacks
if err := l.writeMarker(Marker{Active: true, StoppedStacks: []string{"nextcloud", "immich"}, JobID: "job-x"}); err != nil {
t.Fatal(err)
}
l.Recover()
if got := st.startedNames(); len(got) != 2 || got[0] != "nextcloud" || got[1] != "immich" {
t.Fatalf("recovery did not restart the recorded stacks: %v", got)
}
if _, ok := l.readMarker(); ok {
t.Fatal("recovery did not clear the marker")
}
}
// Recover with no marker is a no-op.
func TestRecover_NoMarker(t *testing.T) {
st := &fakeStacks{}
l := testLoop(t, &fakeBackend{}, st)
l.Recover()
if len(st.startedNames()) != 0 {
t.Fatal("recovery restarted stacks with no marker present")
}
}
// Single-flight: a cycle that begins with an active marker present is a no-op (no second backup).
func TestRunOnce_SingleFlight(t *testing.T) {
be := &fakeBackend{due: true, phases: []string{"done"}}
st := &fakeStacks{running: []string{"a"}}
l := testLoop(t, be, st)
if err := l.writeMarker(Marker{Active: true, StoppedStacks: []string{"a"}}); err != nil {
t.Fatal(err)
}
if err := l.runOnce(context.Background()); err != nil {
t.Fatal(err)
}
if be.startCalls != 0 {
t.Fatal("started a backup while a marker was already active")
}
}
// Only the stacks we stopped are restarted: an already-stopped stack is not in RunningAppStacks,
// so unquiesce never starts it.
func TestRunOnce_OnlyRestartsWhatWeStopped(t *testing.T) {
// "db" was already stopped before quiesce → not in running → not restarted.
be := &fakeBackend{due: true, phases: []string{"done"}}
st := &fakeStacks{running: []string{"web"}} // only web is up
l := testLoop(t, be, st)
if err := l.runOnce(context.Background()); err != nil {
t.Fatal(err)
}
for _, s := range st.startedNames() {
if s == "db" {
t.Fatal("restarted a stack that was already stopped before quiesce")
}
}
if got := st.startedNames(); len(got) != 1 || got[0] != "web" {
t.Fatalf("expected only web restarted, got %v", got)
}
}
// Marker is written BEFORE stacks are stopped (crash-safety ordering): if stop is observed, the
// marker must already exist on disk.
func TestRunOnce_MarkerWrittenBeforeStop(t *testing.T) {
st := &fakeStacks{running: []string{"a"}}
l := testLoop(t, &fakeBackend{due: true, phases: []string{"done"}}, st)
// Wrap StopStack via a stacks decorator that checks the marker file exists at stop time.
markerSeen := false
dec := &stopObserver{inner: st, onStop: func() {
if _, err := os.Stat(l.markerPath); err == nil {
markerSeen = true
}
}}
l.stacks = dec
if err := l.runOnce(context.Background()); err != nil {
t.Fatal(err)
}
if !markerSeen {
t.Fatal("marker was not on disk when the first stack was stopped (crash-safety ordering violated)")
}
}
type stopObserver struct {
inner Stacks
onStop func()
}
func (s *stopObserver) RunningAppStacks() []string { return s.inner.RunningAppStacks() }
func (s *stopObserver) StopStack(n string) error { s.onStop(); return s.inner.StopStack(n) }
func (s *stopObserver) StartStack(n string) error { return s.inner.StartStack(n) }
type errString string
func (e errString) Error() string { return string(e) }