Add stdin support for client and daemon

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

io.go

@@ -8,20 +8,31 @@ import (
 type ioConfig struct {
 	StdoutPath string
 	StderrPath string
-	Stdin      io.WriteCloser
-	Stdout     io.ReadCloser
-	Stderr     io.ReadCloser
+	StdinPath  string
+
+	Stdin  io.WriteCloser
+	Stdout io.ReadCloser
+	Stderr io.ReadCloser
 }
 
 func newCopier(i *ioConfig) (*copier, error) {
 	l := &copier{
 		config: i,
 	}
+	if i.StdinPath != "" {
+		f, err := os.OpenFile(i.StdinPath, os.O_RDONLY, 0)
+		if err != nil {
+			return nil, err
+		}
+		l.closers = append(l.closers, f)
+		go io.Copy(i.Stdin, f)
+	}
 	if i.StdoutPath != "" {
 		f, err := os.OpenFile(i.StdoutPath, os.O_RDWR, 0)
 		if err != nil {
 			return nil, err
 		}
+		l.closers = append(l.closers, f)
 		go io.Copy(f, i.Stdout)
 	}
 	if i.StderrPath != "" {
@@ -29,21 +40,19 @@ func newCopier(i *ioConfig) (*copier, error) {
 		if err != nil {
 			return nil, err
 		}
+		l.closers = append(l.closers, f)
 		go io.Copy(f, i.Stderr)
 	}
 	return l, nil
 }
 
 type copier struct {
-	config *ioConfig
+	config  *ioConfig
+	closers []io.Closer
 }
 
 func (l *copier) Close() (err error) {
-	for _, c := range []io.Closer{
-		l.config.Stdin,
-		l.config.Stdout,
-		l.config.Stderr,
-	} {
+	for _, c := range append(l.closers, l.config.Stdin, l.config.Stdout, l.config.Stderr) {
 		if cerr := c.Close(); err == nil {
 			err = cerr
 		}