update buildah to latest and use new network stack

Make sure buildah uses the new network stack.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

vendor/github.com/containers/buildah/selinux.go

@@ -3,8 +3,12 @@
 package buildah
 
 import (
+	"fmt"
+
 	"github.com/opencontainers/runtime-tools/generate"
 	selinux "github.com/opencontainers/selinux/go-selinux"
+	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
 )
 
 func selinuxGetEnabled() bool {
@@ -17,3 +21,21 @@ func setupSelinux(g *generate.Generator, processLabel, mountLabel string) {
 		g.SetLinuxMountLabel(mountLabel)
 	}
 }
+
+func runLabelStdioPipes(stdioPipe [][]int, processLabel, mountLabel string) error {
+	if !selinuxGetEnabled() || processLabel == "" || mountLabel == "" {
+		// SELinux is completely disabled, or we're not doing anything at all with labeling
+		return nil
+	}
+	pipeContext, err := selinux.ComputeCreateContext(processLabel, mountLabel, "fifo_file")
+	if err != nil {
+		return errors.Wrapf(err, "computing file creation context for pipes")
+	}
+	for i := range stdioPipe {
+		pipeFdName := fmt.Sprintf("/proc/self/fd/%d", stdioPipe[i][0])
+		if err := label.Relabel(pipeFdName, pipeContext, false); err != nil {
+			return errors.Wrapf(err, "setting file label on %q", pipeFdName)
+		}
+	}
+	return nil
+}