Merge pull request sorintlab#541 from sgotti/postgres_consider_standby_if_recovery.conf_exists

postgres: simplify standby role detection

Author: sgotti

internal/postgresql/postgresql.go

@@ -650,18 +650,13 @@ func (p *Manager) IsInitialized() (bool, error) {
 	return true, nil
 }
 
-func (p *Manager) GetRoleFromDB() (common.Role, error) {
-	ctx, cancel := context.WithTimeout(context.Background(), p.requestTimeout)
-	defer cancel()
-	return getRole(ctx, p.localConnParams)
-}
-
 func (p *Manager) GetRole() (common.Role, error) {
-	curConnParams, err := p.GetPrimaryConninfo()
-	if err != nil {
-		return "", fmt.Errorf("error retrieving primary conn info: %v", err)
+	// if recovery.conf exists then consider it as a standby
+	_, err := os.Stat(filepath.Join(p.dataDir, "recovery.conf"))
+	if err != nil && !os.IsNotExist(err) {
+		return "", fmt.Errorf("error determining if recovery.conf exists: %v", err)
 	}
-	if curConnParams == nil {
+	if os.IsNotExist(err) {
 		return common.RoleMaster, nil
 	}
 	return common.RoleStandby, nil
@@ -709,26 +704,6 @@ func (p *Manager) GetPrimarySlotName() (string, error) {
 	return "", nil
 }
 
-func (p *Manager) HasConnParams() (bool, error) {
-	regex := regexp.MustCompile(`primary_conninfo`)
-
-	fh, err := os.Open(filepath.Join(p.dataDir, "recovery.conf"))
-	if os.IsNotExist(err) {
-		return false, nil
-	}
-	defer fh.Close()
-
-	scanner := bufio.NewScanner(fh)
-	scanner.Split(bufio.ScanLines)
-
-	for scanner.Scan() {
-		if regex.MatchString(scanner.Text()) {
-			return true, nil
-		}
-	}
-	return false, nil
-}
-
 func (p *Manager) WriteConf() error {
 	return common.WriteFileAtomicFunc(filepath.Join(p.dataDir, postgresConf), 0600,
 		func(f io.Writer) error {

internal/postgresql/utils.go

@@ -206,31 +206,6 @@ func dropReplicationSlot(ctx context.Context, connParams ConnParams, name string
 	return err
 }
 
-func getRole(ctx context.Context, connParams ConnParams) (common.Role, error) {
-	db, err := sql.Open("postgres", connParams.ConnString())
-	if err != nil {
-		return "", err
-	}
-	defer db.Close()
-
-	rows, err := query(ctx, db, "select pg_is_in_recovery from pg_is_in_recovery()")
-	if err != nil {
-		return "", err
-	}
-	defer rows.Close()
-	for rows.Next() {
-		var isInRecovery bool
-		if err := rows.Scan(&isInRecovery); err != nil {
-			return "", err
-		}
-		if isInRecovery {
-			return common.RoleStandby, nil
-		}
-		return common.RoleMaster, nil
-	}
-	return "", fmt.Errorf("no rows returned")
-}
-
 func getSyncStandbys(ctx context.Context, connParams ConnParams) ([]string, error) {
 	db, err := sql.Open("postgres", connParams.ConnString())
 	if err != nil {