1 files changed, 260 insertions, 0 deletions
diff --git a/vendor/github.com/sevlyar/go-daemon/daemon_unix.go b/vendor/github.com/sevlyar/go-daemon/daemon_unix.go
new file mode 100644
index 0000000..3bd7dc9
--- /dev/null
+++ b/vendor/github.com/sevlyar/go-daemon/daemon_unix.go
@@ -0,0 +1,260 @@
+// +build darwin dragonfly freebsd linux netbsd openbsd plan9 solaris
+
+package daemon
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"syscall"
+)
+
+// A Context describes daemon context.
+type Context struct {
+	// If PidFileName is non-empty, parent process will try to create and lock
+	// pid file with given name. Child process writes process id to file.
+	PidFileName string
+	// Permissions for new pid file.
+	PidFilePerm os.FileMode
+
+	// If LogFileName is non-empty, parent process will create file with given name
+	// and will link to fd 2 (stderr) for child process.
+	LogFileName string
+	// Permissions for new log file.
+	LogFilePerm os.FileMode
+
+	// If WorkDir is non-empty, the child changes into the directory before
+	// creating the process.
+	WorkDir string
+	// If Chroot is non-empty, the child changes root directory
+	Chroot string
+
+	// If Env is non-nil, it gives the environment variables for the
+	// daemon-process in the form returned by os.Environ.
+	// If it is nil, the result of os.Environ will be used.
+	Env []string
+	// If Args is non-nil, it gives the command-line args for the
+	// daemon-process. If it is nil, the result of os.Args will be used.
+	Args []string
+
+	// Credential holds user and group identities to be assumed by a daemon-process.
+	Credential *syscall.Credential
+	// If Umask is non-zero, the daemon-process call Umask() func with given value.
+	Umask int
+
+	// Struct contains only serializable public fields (!!!)
+	abspath  string
+	pidFile  *LockFile
+	logFile  *os.File
+	nullFile *os.File
+
+	rpipe, wpipe *os.File
+}
+
+func (d *Context) reborn() (child *os.Process, err error) {
+	if !WasReborn() {
+		child, err = d.parent()
+	} else {
+		err = d.child()
+	}
+	return
+}
+
+func (d *Context) search() (daemon *os.Process, err error) {
+	if len(d.PidFileName) > 0 {
+		var pid int
+		if pid, err = ReadPidFile(d.PidFileName); err != nil {
+			return
+		}
+		daemon, err = os.FindProcess(pid)
+	}
+	return
+}
+
+func (d *Context) parent() (child *os.Process, err error) {
+	if err = d.prepareEnv(); err != nil {
+		return
+	}
+
+	defer d.closeFiles()
+	if err = d.openFiles(); err != nil {
+		return
+	}
+
+	attr := &os.ProcAttr{
+		Dir:   d.WorkDir,
+		Env:   d.Env,
+		Files: d.files(),
+		Sys: &syscall.SysProcAttr{
+			//Chroot:     d.Chroot,
+			Credential: d.Credential,
+			Setsid:     true,
+		},
+	}
+
+	if child, err = os.StartProcess(d.abspath, d.Args, attr); err != nil {
+		if d.pidFile != nil {
+			d.pidFile.Remove()
+		}
+		return
+	}
+
+	d.rpipe.Close()
+	encoder := json.NewEncoder(d.wpipe)
+	if err = encoder.Encode(d); err != nil {
+		return
+	}
+	_, err = fmt.Fprint(d.wpipe, "\n\n")
+	return
+}
+
+func (d *Context) openFiles() (err error) {
+	if d.PidFilePerm == 0 {
+		d.PidFilePerm = FILE_PERM
+	}
+	if d.LogFilePerm == 0 {
+		d.LogFilePerm = FILE_PERM
+	}
+
+	if d.nullFile, err = os.Open(os.DevNull); err != nil {
+		return
+	}
+
+	if len(d.PidFileName) > 0 {
+		if d.PidFileName, err = filepath.Abs(d.PidFileName); err != nil {
+			return err
+		}
+		if d.pidFile, err = OpenLockFile(d.PidFileName, d.PidFilePerm); err != nil {
+			return
+		}
+		if err = d.pidFile.Lock(); err != nil {
+			return
+		}
+		if len(d.Chroot) > 0 {
+			// Calculate PID-file absolute path in child's environment
+			if d.PidFileName, err = filepath.Rel(d.Chroot, d.PidFileName); err != nil {
+				return err
+			}
+			d.PidFileName = "/" + d.PidFileName
+		}
+	}
+
+	if len(d.LogFileName) > 0 {
+		if d.logFile, err = os.OpenFile(d.LogFileName,
+			os.O_WRONLY|os.O_CREATE|os.O_APPEND, d.LogFilePerm); err != nil {
+			return
+		}
+	}
+
+	d.rpipe, d.wpipe, err = os.Pipe()
+	return
+}
+
+func (d *Context) closeFiles() (err error) {
+	cl := func(file **os.File) {
+		if *file != nil {
+			(*file).Close()
+			*file = nil
+		}
+	}
+	cl(&d.rpipe)
+	cl(&d.wpipe)
+	cl(&d.logFile)
+	cl(&d.nullFile)
+	if d.pidFile != nil {
+		d.pidFile.Close()
+		d.pidFile = nil
+	}
+	return
+}
+
+func (d *Context) prepareEnv() (err error) {
+	if d.abspath, err = osExecutable(); err != nil {
+		return
+	}
+
+	if len(d.Args) == 0 {
+		d.Args = os.Args
+	}
+
+	mark := fmt.Sprintf("%s=%s", MARK_NAME, MARK_VALUE)
+	if len(d.Env) == 0 {
+		d.Env = os.Environ()
+	}
+	d.Env = append(d.Env, mark)
+
+	return
+}
+
+func (d *Context) files() (f []*os.File) {
+	log := d.nullFile
+	if d.logFile != nil {
+		log = d.logFile
+	}
+
+	f = []*os.File{
+		d.rpipe,    // (0) stdin
+		log,        // (1) stdout
+		log,        // (2) stderr
+		d.nullFile, // (3) dup on fd 0 after initialization
+	}
+
+	if d.pidFile != nil {
+		f = append(f, d.pidFile.File) // (4) pid file
+	}
+	return
+}
+
+var initialized = false
+
+func (d *Context) child() (err error) {
+	if initialized {
+		return os.ErrInvalid
+	}
+	initialized = true
+
+	decoder := json.NewDecoder(os.Stdin)
+	if err = decoder.Decode(d); err != nil {
+		return
+	}
+
+	// create PID file after context decoding to know PID file full path.
+	if len(d.PidFileName) > 0 {
+		d.pidFile = NewLockFile(os.NewFile(4, d.PidFileName))
+		if err = d.pidFile.WritePid(); err != nil {
+			return
+		}
+		defer func() {
+			if err != nil {
+				d.pidFile.Remove()
+			}
+		}()
+	}
+
+	if err = syscallDup(3, 0); err != nil {
+		return
+	}
+
+	if d.Umask != 0 {
+		syscall.Umask(int(d.Umask))
+	}
+	if len(d.Chroot) > 0 {
+		err = syscall.Chroot(d.Chroot)
+		if err != nil {
+			return
+		}
+	}
+
+	return
+}
+
+func (d *Context) release() (err error) {
+	if !initialized {
+		return
+	}
+	if d.pidFile != nil {
+		err = d.pidFile.Remove()
+	}
+	return
+}