runsc: Pass root container's stdio via FD.

We were previously using the sandbox process's stdio as the root container's
stdio. This makes it difficult/impossible to distinguish output application
output from sandbox output, such as panics, which are always written to stderr.

Also close the console socket when we are done with it.

PiperOrigin-RevId: 215585180
Change-Id: I980b8c69bd61a8b8e0a496fd7bc90a06446764e0

2 files changed, 5 insertions, 4 deletions

diff --git a/runsc/boot/loader.go b/runsc/boot/loader.go
index 766a2e968..726482bb2 100644
--- a/runsc/boot/loader.go
+++ b/runsc/boot/loader.go
@@ -140,7 +140,7 @@ func init() {
 
 // New initializes a new kernel loader configured by spec.
 // New also handles setting up a kernel for restoring a container.
-func New(id string, spec *specs.Spec, conf *Config, controllerFD, deviceFD int, goferFDs []int, console bool) (*Loader, error) {
+func New(id string, spec *specs.Spec, conf *Config, controllerFD, deviceFD int, goferFDs []int, stdioFDs []int, console bool) (*Loader, error) {
 	if err := usage.Init(); err != nil {
 		return nil, fmt.Errorf("Error setting up memory usage: %v", err)
 	}
@@ -279,9 +279,9 @@ func New(id string, spec *specs.Spec, conf *Config, controllerFD, deviceFD int,
 		conf:                  conf,
 		console:               console,
 		watchdog:              watchdog,
-		stdioFDs:              []int{syscall.Stdin, syscall.Stdout, syscall.Stderr},
-		goferFDs:              goferFDs,
 		spec:                  spec,
+		goferFDs:              goferFDs,
+		stdioFDs:              stdioFDs,
 		startSignalForwarding: startSignalForwarding,
 		rootProcArgs:          procArgs,
 		sandboxID:             id,
diff --git a/runsc/boot/loader_test.go b/runsc/boot/loader_test.go
index 0b363253d..ea8411a8b 100644
--- a/runsc/boot/loader_test.go
+++ b/runsc/boot/loader_test.go
@@ -101,7 +101,8 @@ func createLoader() (*Loader, func(), error) {
 		return nil, nil, err
 	}
 
-	l, err := New("foo", spec, conf, fd, -1 /* device fd */, []int{sandEnd}, false)
+	stdio := []int{int(os.Stdin.Fd()), int(os.Stdout.Fd()), int(os.Stderr.Fd())}
+	l, err := New("foo", spec, conf, fd, -1 /* device fd */, []int{sandEnd}, stdio, false)
 	if err != nil {
 		cleanup()
 		return nil, nil, err