zoopb/config.go

package zoopb

// functions to import and export the protobuf
// data to and from config files

import (
	"errors"
	"os"
	"path/filepath"

	"go.wit.com/log"
	"google.golang.org/protobuf/proto"
)

// writes out the cluster information it seperate files
// to make it humanly possible to hand edit things as needed
func (m *Machines) ConfigSave() error {
	data, err := m.Marshal()
	if err != nil {
		log.Info("proto.Marshal() failed len", len(data), err)
		return err
	}
	log.Info("proto.Marshal() worked len", len(data))
	configWrite(data)
	return nil
}

// when running on a single machine, save the file in forge/
// as <hostname>.pb
// write to ~/.config/forge/ unless ENV{FORGE_HOME} is set
func (m *Machine) ConfigSave() error {
	if os.Getenv("FORGE_HOME") == "" {
		homeDir, _ := os.UserHomeDir()
		fullpath := filepath.Join(homeDir, ".config/forge")
		os.Setenv("FORGE_HOME", fullpath)
	}
	data, err := m.Marshal()
	if err != nil {
		log.Info("proto.Marshal() failed len", len(data), err)
		return err
	}

	log.Info("ConfigSave() proto.Marshal() worked len", len(data))

	hostname, _ := os.Hostname()
	fname := hostname + ".pb"
	return m.configWrite(fname, data)
}

func ConfigSaveRaw(data []byte) error {
	configWrite(data)
	return nil
}

func (m *Machines) ConfigLoad() error {
	if m == nil {
		return errors.New("It's not safe to run ConfigLoad() on a nil ?")
	}

	if data, err := loadFile("zookeeper.pb"); err == nil {
		if err = proto.Unmarshal(data, m); err != nil {
			log.Warn("broken zookeeper.pb config file")
			return err
		}
	} else {
		return err
	}
	return nil
}

func (m *Machine) ConfigLoad() error {
	if m == nil {
		return errors.New("It's not safe to run ConfigLoad() on a nil ?")
	}
	if os.Getenv("FORGE_HOME") == "" {
		homeDir, _ := os.UserHomeDir()
		fullpath := filepath.Join(homeDir, ".config/forge")
		os.Setenv("FORGE_HOME", fullpath)
	}

	hostname, _ := os.Hostname()
	fname := hostname + ".pb"

	var data []byte
	var err error
	if data, err = loadFile(fname); err != nil {
		// something went wrong loading the file
		return err
	}

	if data != nil {
		if err = proto.Unmarshal(data, m); err != nil {
			log.Warn("broken zookeeper.pb config file", fname)
			return err
		}
		return nil
	}

	m.Hostname = hostname
	m.Distro = detectDistro()
	m.initPackages()
	log.Info("zoopb.ConfigLoad()", m.Hostname, "runs", m.Distro, "with", m.Packages.Len(), "packages")
	return nil
}

func loadFile(filename string) ([]byte, error) {
	homeDir, err := os.UserHomeDir()
	p := filepath.Join(homeDir, ".config/zookeeper")
	fullname := filepath.Join(p, filename)
	data, err := os.ReadFile(fullname)
	if errors.Is(err, os.ErrNotExist) {
		// if file does not exist, just return nil. this
		// will cause ConfigLoad() to try the next config file like "forge.text"
		// because the user might want to edit the .config by hand
		return nil, nil
	}
	if err != nil {
		// log.Info("open config file :", err)
		return nil, err
	}
	return data, nil
}

func (m *Machine) loadFile(fname string) ([]byte, error) {
	fullname := filepath.Join(os.Getenv("FORGE_HOME"), fname)

	data, err := os.ReadFile(fullname)
	if err != nil {
		// log.Info("open config file :", err)
		return nil, err
	}
	return data, nil
}

func configWrite(data []byte) error {
	homeDir, err := os.UserHomeDir()
	p := filepath.Join(homeDir, ".config/zookeeper")
	fname := filepath.Join(p, "zookeeper.pb")
	cfgfile, err := os.OpenFile(fname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
	defer cfgfile.Close()
	if err != nil {
		log.Warn("open config file :", err)
		return err
	}
	cfgfile.Write(data)
	return nil
}

func (m *Machine) configWrite(fname string, data []byte) error {
	fullname := filepath.Join(os.Getenv("FORGE_HOME"), fname)

	cfgfile, err := os.OpenFile(fullname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
	defer cfgfile.Close()
	if err != nil {
		log.Warn("open config file :", err)
		return err
	}
	cfgfile.Write(data)
	return nil
}