stability: move events log from $SNAP_COMMON to $SNAP_DATA

.drone.jsonnet

@@ -10,7 +10,7 @@ local bootstrap = '25.02';
 local nginx = '1.24.0';
 local python = '3.12-slim-bookworm';
 local alpine = '3.21';
-local visual_diff_skip_build = '2786';
+local visual_diff_skip_build = '2837';
 
 local build(arch, testUI) = [{
   kind: 'pipeline',

backend/cmd/stability/main.go

@@ -1,38 +1,29 @@
 package main
 
 import (
-	"context"
-	"os"
-	"os/signal"
+	"path"
 	"syscall"
 
+	"github.com/syncloud/platform/hook"
 	"github.com/syncloud/platform/log"
 	"github.com/syncloud/platform/stability"
 )
 
 func main() {
 	logger := log.Default()
-	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
-	defer cancel()
-
 	mem := stability.NewMemInfo("/proc")
-	commonDir := os.Getenv("SNAP_COMMON")
-	if commonDir == "" {
-		commonDir = "/var/snap/platform/common"
-	}
-	events := stability.NewEventLog(commonDir + "/stability-events.jsonl")
-	z := stability.NewZram(mem, stability.SwaponSyscall, stability.SwapoffSyscall, events, logger)
-	if err := z.EnsureConfigured(); err != nil {
+	eventsPath := path.Join(hook.DataDir, "stability-events.jsonl")
+	stability.MigrateEventLog(path.Join(hook.CommonDir, "stability-events.jsonl"), eventsPath, logger)
+	events := stability.NewEventLog(eventsPath)
+	zram := stability.NewZram(mem, stability.SwaponSyscall, stability.SwapoffSyscall, events, logger)
+	if err := zram.EnsureConfigured(); err != nil {
 		logger.Sugar().Warnf("stability: zram setup failed (continuing): %v", err)
 	}
 
-	scan := stability.NewProcScanner("/proc")
-	w := stability.NewWatcher(mem, scan, func(pid int, sig syscall.Signal) error {
+	scanner := stability.NewProcScanner("/proc")
+	watcher := stability.NewWatcher(mem, scanner, func(pid int, sig syscall.Signal) error {
 		return syscall.Kill(pid, sig)
 	}, events, logger)
 
-	if err := w.Run(ctx); err != nil && err != context.Canceled {
-		logger.Sugar().Errorf("stability: watcher exited: %v", err)
-		os.Exit(1)
-	}
+	watcher.Run()
 }

backend/ioc/common.go

@@ -572,8 +572,8 @@ func Init(userConfig string, systemConfig string, backupDir string, varDir strin
 		return nil, err
 	}
 
-	err = c.Singleton(func() *stability.EventLog {
-		return stability.NewEventLog("/var/snap/platform/common/stability-events.jsonl")
+	err = c.Singleton(func(systemConfig *config.SystemConfig) *stability.EventLog {
+		return stability.NewEventLog(path.Join(systemConfig.DataDir(), "stability-events.jsonl"))
 	})
 	if err != nil {
 		return nil, err

backend/stability/migrate.go

@@ -0,0 +1,25 @@
+package stability
+
+import (
+	"errors"
+	"os"
+
+	"go.uber.org/zap"
+)
+
+func MigrateEventLog(oldPath, newPath string, logger *zap.Logger) {
+	if _, err := os.Stat(newPath); err == nil {
+		return
+	} else if !errors.Is(err, os.ErrNotExist) {
+		logger.Warn("stability: stat new event log failed", zap.Error(err))
+		return
+	}
+	if _, err := os.Stat(oldPath); err != nil {
+		return
+	}
+	if err := os.Rename(oldPath, newPath); err != nil {
+		logger.Warn("stability: migrate event log failed", zap.String("from", oldPath), zap.String("to", newPath), zap.Error(err))
+		return
+	}
+	logger.Info("stability: migrated event log", zap.String("from", oldPath), zap.String("to", newPath))
+}

backend/stability/migrate_test.go

@@ -0,0 +1,54 @@
+package stability
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
+)
+
+func TestMigrateMovesWhenOnlyOldExists(t *testing.T) {
+	dir := t.TempDir()
+	old := filepath.Join(dir, "common", "events.jsonl")
+	newP := filepath.Join(dir, "data", "events.jsonl")
+	require.NoError(t, os.MkdirAll(filepath.Dir(old), 0755))
+	require.NoError(t, os.MkdirAll(filepath.Dir(newP), 0755))
+	require.NoError(t, os.WriteFile(old, []byte("{\"kind\":\"x\"}\n"), 0644))
+
+	MigrateEventLog(old, newP, zap.NewNop())
+
+	_, errOld := os.Stat(old)
+	assert.True(t, os.IsNotExist(errOld))
+	body, err := os.ReadFile(newP)
+	require.NoError(t, err)
+	assert.Equal(t, "{\"kind\":\"x\"}\n", string(body))
+}
+
+func TestMigrateSkipsWhenNewAlreadyExists(t *testing.T) {
+	dir := t.TempDir()
+	old := filepath.Join(dir, "events.jsonl")
+	newP := filepath.Join(dir, "new.jsonl")
+	require.NoError(t, os.WriteFile(old, []byte("old"), 0644))
+	require.NoError(t, os.WriteFile(newP, []byte("new"), 0644))
+
+	MigrateEventLog(old, newP, zap.NewNop())
+
+	oldBody, _ := os.ReadFile(old)
+	newBody, _ := os.ReadFile(newP)
+	assert.Equal(t, "old", string(oldBody), "old file untouched if new exists")
+	assert.Equal(t, "new", string(newBody), "new file untouched if new exists")
+}
+
+func TestMigrateNoopWhenOldMissing(t *testing.T) {
+	dir := t.TempDir()
+	old := filepath.Join(dir, "missing.jsonl")
+	newP := filepath.Join(dir, "new.jsonl")
+
+	MigrateEventLog(old, newP, zap.NewNop())
+
+	_, err := os.Stat(newP)
+	assert.True(t, os.IsNotExist(err))
+}

backend/stability/oom.go

@@ -1,7 +1,6 @@
 package stability
 
 import (
-	"context"
 	"errors"
 	"os"
 	"syscall"
@@ -42,22 +41,17 @@ func NewWatcher(mem *MemInfo, scan *ProcScanner, kill KillFn, events *EventLog,
 	}
 }
 
-func (w *Watcher) Run(ctx context.Context) error {
+func (w *Watcher) Run() {
 	t := time.NewTicker(w.interval)
 	defer t.Stop()
 	w.log.Info("oom-watcher: started",
 		zap.Duration("interval", w.interval),
 		zap.Float64("avail_min", w.availMin),
 		zap.Float64("psi_max", w.psiMax),
 	)
-	for {
-		select {
-		case <-ctx.Done():
-			return ctx.Err()
-		case <-t.C:
-			if err := w.tick(); err != nil {
-				w.log.Warn("oom-watcher: tick error", zap.Error(err))
-			}
+	for range t.C {
+		if err := w.tick(); err != nil {
+			w.log.Warn("oom-watcher: tick error", zap.Error(err))
 		}
 	}
 }