Update to the latest version of buildah

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/github.com/containers/common/pkg/config/default_linux.go

@@ -0,0 +1,55 @@
+package config
+
+import (
+	"fmt"
+	"io/ioutil"
+	"strconv"
+	"strings"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// isCgroup2UnifiedMode returns whether we are running in cgroup2 mode.
+func isCgroup2UnifiedMode() (isUnified bool, isUnifiedErr error) {
+	cgroupRoot := "/sys/fs/cgroup"
+
+	var st syscall.Statfs_t
+	if err := syscall.Statfs(cgroupRoot, &st); err != nil {
+		isUnified, isUnifiedErr = false, err
+	} else {
+		isUnified, isUnifiedErr = st.Type == unix.CGROUP2_SUPER_MAGIC, nil
+	}
+	return
+}
+
+const (
+	oldMaxSize = uint64(1048576)
+)
+
+// getDefaultProcessLimits returns the nproc for the current process in ulimits format
+// Note that nfile sometimes cannot be set to unlimited, and the limit is hardcoded
+// to (oldMaxSize) 1048576 (2^20), see: http://stackoverflow.com/a/1213069/1811501
+// In rootless containers this will fail, and the process will just use its current limits
+func getDefaultProcessLimits() []string {
+	rlim := unix.Rlimit{Cur: oldMaxSize, Max: oldMaxSize}
+	oldrlim := rlim
+	// Attempt to set file limit and process limit to pid_max in OS
+	dat, err := ioutil.ReadFile("/proc/sys/kernel/pid_max")
+	if err == nil {
+		val := strings.TrimSuffix(string(dat), "\n")
+		max, err := strconv.ParseUint(val, 10, 64)
+		if err == nil {
+			rlim = unix.Rlimit{Cur: uint64(max), Max: uint64(max)}
+		}
+	}
+	defaultLimits := []string{}
+	if err := unix.Setrlimit(unix.RLIMIT_NPROC, &rlim); err == nil {
+		defaultLimits = append(defaultLimits, fmt.Sprintf("nproc=%d:%d", rlim.Cur, rlim.Max))
+	} else {
+		if err := unix.Setrlimit(unix.RLIMIT_NPROC, &oldrlim); err == nil {
+			defaultLimits = append(defaultLimits, fmt.Sprintf("nproc=%d:%d", oldrlim.Cur, oldrlim.Max))
+		}
+	}
+	return defaultLimits
+}