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

51 lines
1.6 KiB
Go

package config
import (
"fmt"
"io/ioutil"
"strconv"
"strings"
"golang.org/x/sys/unix"
)
const (
oldMaxSize = uint64(1048576)
)
// getDefaultMachineImage returns the default machine image stream
// On Linux/Mac, this returns the FCOS stream
func getDefaultMachineImage() string {
return "testing"
}
// getDefaultMachineUser returns the user to use for rootless podman
func getDefaultMachineUser() string {
return "core"
}
// 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
}