Example #1
0
func (p *Process) assumePrimary(downstream *discoverd.Instance) (err error) {
	log := p.log.New("fn", "assumePrimary")
	if downstream != nil {
		log = log.New("downstream", downstream.Addr)
	}

	if p.running() && p.config().Role == state.RoleSync {
		log.Info("promoting to primary")

		if err := ioutil.WriteFile(p.triggerPath(), nil, 0655); err != nil {
			log.Error("error creating trigger file", "path", p.triggerPath(), "err", err)
			return err
		}

		p.waitForSync(downstream, true)

		return nil
	}

	log.Info("starting as primary")

	if p.running() {
		panic(fmt.Sprintf("unexpected state running role=%s", p.config().Role))
	}

	if err := p.initDB(); err != nil {
		return err
	}

	if err := os.Remove(p.recoveryConfPath()); err != nil && !os.IsNotExist(err) {
		log.Error("error removing recovery.conf", "path", p.recoveryConfPath(), "err", err)
		return err
	}

	if err := p.writeConfig(configData{ReadOnly: downstream != nil}); err != nil {
		log.Error("error writing postgres.conf", "path", p.configPath(), "err", err)
		return err
	}

	if err := p.start(); err != nil {
		return err
	}

	var tx *pgx.Tx
	defer func() {
		if err != nil {
			if tx != nil {
				tx.Rollback()
			}
			p.db.Close()
			if err := p.stop(); err != nil {
				log.Debug("ignoring error stopping postgres", "err", err)
			}
		}
	}()

	tx, err = p.db.Begin()
	if err != nil {
		log.Error("error acquiring connection", "err", err)
		return err
	}
	if _, err := tx.Exec("SET TRANSACTION READ WRITE"); err != nil {
		log.Error("error setting transaction read-write", "err", err)
		return err
	}
	if _, err := tx.Exec(fmt.Sprintf(`
		DO
		$body$
		BEGIN
		   IF NOT EXISTS (
			  SELECT * FROM pg_catalog.pg_user
			  WHERE	usename = 'flynn')
		   THEN
			  CREATE USER flynn WITH SUPERUSER CREATEDB CREATEROLE REPLICATION PASSWORD '%s';
		   END IF;
		END
		$body$;
	`, p.password)); err != nil {
		log.Error("error creating superuser", "err", err)
		return err
	}
	if err := tx.Commit(); err != nil {
		log.Error("error committing transaction", "err", err)
		return err
	}

	if downstream != nil {
		p.waitForSync(downstream, true)
	}

	return nil
}