process.go

// Copyright © 2014 Terry Mao, LiuDing All rights reserved.
// This file is part of gosnowflake.

// gosnowflake is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// gosnowflake is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with gosnowflake.  If not, see <http://www.gnu.org/licenses/>.

package main

import (
	"fmt"
	"io/ioutil"
	"os"
)

const (
	defaultUser  = "nobody"
	defaultGroup = "nobody"
)

// InitProcess create pid file, set working dir, setgid and setuid.
func InitProcess() (err error) {
	// change working dir
	if err = os.Chdir(MyConf.Dir); err != nil {
		return
	}
	// create pid file
	if err = ioutil.WriteFile(MyConf.PidFile, []byte(fmt.Sprintf("%d\n", os.Getpid())), 0644); err != nil {
		return
	}
	/*
		// setuid and setgid
		ug := strings.SplitN(MyConf.User, " ", 2)
		usr := defaultUser
		grp := defaultGroup
		if len(ug) == 0 {
			// default user and group (nobody)
		} else if len(ug) == 1 {
			usr = ug[0]
			grp = ""
		} else if len(ug) == 2 {
			usr = ug[0]
			grp = ug[1]
		}
		uid := 0
		gid := 0
		ui, err := user.Lookup(usr)
		if err != nil {
			return err
		}
		uid, _ = strconv.Atoi(ui.Uid)
		// group no set
		if grp == "" {
			gid, _ = strconv.Atoi(ui.Gid)
		} else {
			// use user's group instread
			// TODO LookupGroup
			gid, _ = strconv.Atoi(ui.Gid)
		}
		if err := syscall.Setgid(gid); err != nil {
			return err
		}
		if err := syscall.Setuid(uid); err != nil {
			return err
		}
	*/
	return
}