repo_description: PostgreSQL cloud native High Availability and more.
repo_topics: cloud-native consul data-consistency declarative-config disaster-recovery docker etcd golang high-availability kubernetes postgresql standby-cluster synchronous-replication
code: // Copyright 2016 Sorint.lab
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  package postgresql
  
  import (
  	"encoding/binary"
  	"os"
  	"path/filepath"
  	"strconv"
  )
  
  func (p *Manager) GetSystemdID() (string, error) {
  	pgControl, err := os.Open(filepath.Join(p.dataDir, "global", "pg_control"))
  	if err != nil {
  		return "", err
  	}
  	var systemID uint64
  	err = binary.Read(pgControl, binary.LittleEndian, &systemID)
  	if err != nil {
  		return "", err
  	}
  	return strconv.FormatUint(systemID, 10), nil
  }
  