Move linux only Process.InitializeIO behind the linux build flag.

Signed-off-by: David Calavera <david.calavera@gmail.com>

libcontainer/process.go

@@ -5,7 +5,6 @@ import (
 	"io"
 	"math"
 	"os"
-	"syscall"
 )
 
 type processOperations interface {
@@ -86,47 +85,6 @@ type IO struct {
 	Stderr io.ReadCloser
 }
 
-// InitializeIO creates pipes for use with the process's STDIO
-// and returns the opposite side for each
-func (p *Process) InitializeIO(rootuid int) (i *IO, err error) {
-	var fds []uintptr
-	i = &IO{}
-	// cleanup in case of an error
-	defer func() {
-		if err != nil {
-			for _, fd := range fds {
-				syscall.Close(int(fd))
-			}
-		}
-	}()
-	// STDIN
-	r, w, err := os.Pipe()
-	if err != nil {
-		return nil, err
-	}
-	fds = append(fds, r.Fd(), w.Fd())
-	p.Stdin, i.Stdin = r, w
-	// STDOUT
-	if r, w, err = os.Pipe(); err != nil {
-		return nil, err
-	}
-	fds = append(fds, r.Fd(), w.Fd())
-	p.Stdout, i.Stdout = w, r
-	// STDERR
-	if r, w, err = os.Pipe(); err != nil {
-		return nil, err
-	}
-	fds = append(fds, r.Fd(), w.Fd())
-	p.Stderr, i.Stderr = w, r
-	// change ownership of the pipes incase we are in a user namespace
-	for _, fd := range fds {
-		if err := syscall.Fchown(int(fd), rootuid, rootuid); err != nil {
-			return nil, err
-		}
-	}
-	return i, nil
-}
-
 // NewConsole creates new console for process and returns it
 func (p *Process) NewConsole(rootuid int) (Console, error) {
 	console, err := NewConsole(rootuid, rootuid)

libcontainer/process_linux.go

@@ -320,3 +320,44 @@ func getPipeFds(pid int) ([]string, error) {
 	}
 	return fds, nil
 }
+
+// InitializeIO creates pipes for use with the process's STDIO
+// and returns the opposite side for each
+func (p *Process) InitializeIO(rootuid int) (i *IO, err error) {
+	var fds []uintptr
+	i = &IO{}
+	// cleanup in case of an error
+	defer func() {
+		if err != nil {
+			for _, fd := range fds {
+				syscall.Close(int(fd))
+			}
+		}
+	}()
+	// STDIN
+	r, w, err := os.Pipe()
+	if err != nil {
+		return nil, err
+	}
+	fds = append(fds, r.Fd(), w.Fd())
+	p.Stdin, i.Stdin = r, w
+	// STDOUT
+	if r, w, err = os.Pipe(); err != nil {
+		return nil, err
+	}
+	fds = append(fds, r.Fd(), w.Fd())
+	p.Stdout, i.Stdout = w, r
+	// STDERR
+	if r, w, err = os.Pipe(); err != nil {
+		return nil, err
+	}
+	fds = append(fds, r.Fd(), w.Fd())
+	p.Stderr, i.Stderr = w, r
+	// change ownership of the pipes incase we are in a user namespace
+	for _, fd := range fds {
+		if err := syscall.Fchown(int(fd), rootuid, rootuid); err != nil {
+			return nil, err
+		}
+	}
+	return i, nil
+}