Also remove wal directory when destroying data

If a wal directory is supplied then it's important to clean-out our wals
along with our data directory. This commit renames the existing
RemoveAll method to RemoveAllIfInitialized, which better represents what
it does, and has it rely on a RemoveAll method that cleans-up both data
directory and wal.

cmd/keeper/cmd/keeper.go

@@ -830,7 +830,7 @@ func (p *PostgresKeeper) resync(db, followedDB *cluster.DB, tryPgrewind bool) er
 		replSlot = common.StolonName(db.UID)
 	}
 
-	if err := pgm.RemoveAll(); err != nil {
+	if err := pgm.RemoveAllIfInitialized(); err != nil {
 		return fmt.Errorf("failed to remove the postgres data dir: %v", err)
 	}
 	if slog.IsDebug() {
@@ -1023,7 +1023,7 @@ func (p *PostgresKeeper) postgresKeeperSM(pctx context.Context) {
 		}
 
 		// Clean up cluster db datadir
-		if err = pgm.RemoveAll(); err != nil {
+		if err = pgm.RemoveAllIfInitialized(); err != nil {
 			log.Errorw("failed to remove the postgres data dir", zap.Error(err))
 			return
 		}
@@ -1082,7 +1082,7 @@ func (p *PostgresKeeper) postgresKeeperSM(pctx context.Context) {
 				log.Errorw("failed to stop pg instance", zap.Error(err))
 				return
 			}
-			if err = pgm.RemoveAll(); err != nil {
+			if err = pgm.RemoveAllIfInitialized(); err != nil {
 				log.Errorw("failed to remove the postgres data dir", zap.Error(err))
 				return
 			}
@@ -1144,7 +1144,7 @@ func (p *PostgresKeeper) postgresKeeperSM(pctx context.Context) {
 				log.Errorw("failed to stop pg instance", zap.Error(err))
 				return
 			}
-			if err = pgm.RemoveAll(); err != nil {
+			if err = pgm.RemoveAllIfInitialized(); err != nil {
 				log.Errorw("failed to remove the postgres data dir", zap.Error(err))
 				return
 			}

internal/postgresql/postgresql.go

@@ -208,7 +208,7 @@ func (p *Manager) Init(initConfig *InitConfig) error {
 	}
 	// remove the dataDir, so we don't end with an half initialized database
 	if err != nil {
-		os.RemoveAll(p.dataDir)
+		p.RemoveAll()
 		return err
 	}
 	return nil
@@ -237,7 +237,7 @@ func (p *Manager) Restore(command string) error {
 	// On every error remove the dataDir, so we don't end with an half initialized database
 out:
 	if err != nil {
-		os.RemoveAll(p.dataDir)
+		p.RemoveAll()
 		return err
 	}
 	return nil
@@ -853,7 +853,7 @@ func (p *Manager) SyncFromFollowed(followedConnParams ConnParams, replSlot strin
 	return nil
 }
 
-func (p *Manager) RemoveAll() error {
+func (p *Manager) RemoveAllIfInitialized() error {
 	initialized, err := p.IsInitialized()
 	if err != nil {
 		return fmt.Errorf("failed to retrieve instance state: %v", err)
@@ -869,6 +869,17 @@ func (p *Manager) RemoveAll() error {
 	if started {
 		return fmt.Errorf("cannot remove postregsql database. Instance is active")
 	}
+
+	return p.RemoveAll()
+}
+
+// RemoveAll entirely cleans up the data directory, including any wal directory if that
+// exists outside of the data directory.
+func (p *Manager) RemoveAll() error {
+	if p.walDir != "" {
+		os.RemoveAll(p.walDir)
+	}
+
 	return os.RemoveAll(p.dataDir)
 }