runc/utils.go

122 lines
2.6 KiB
Go

package main
import (
"fmt"
"os"
"path/filepath"
"strconv"
"strings"
"github.com/opencontainers/runtime-spec/specs-go"
"github.com/sirupsen/logrus"
"github.com/urfave/cli"
)
const (
exactArgs = iota
minArgs
maxArgs
)
func checkArgs(context *cli.Context, expected, checkType int) error {
var err error
cmdName := context.Command.Name
switch checkType {
case exactArgs:
if context.NArg() != expected {
err = fmt.Errorf("%s: %q requires exactly %d argument(s)", os.Args[0], cmdName, expected)
}
case minArgs:
if context.NArg() < expected {
err = fmt.Errorf("%s: %q requires a minimum of %d argument(s)", os.Args[0], cmdName, expected)
}
case maxArgs:
if context.NArg() > expected {
err = fmt.Errorf("%s: %q requires a maximum of %d argument(s)", os.Args[0], cmdName, expected)
}
}
if err != nil {
fmt.Printf("Incorrect Usage.\n\n")
_ = cli.ShowCommandHelp(context, cmdName)
return err
}
return nil
}
func logrusToStderr() bool {
l, ok := logrus.StandardLogger().Out.(*os.File)
return ok && l.Fd() == os.Stderr.Fd()
}
// fatal prints the error's details if it is a libcontainer specific error type
// then exits the program with an exit status of 1.
func fatal(err error) {
fatalWithCode(err, 1)
}
func fatalWithCode(err error, ret int) {
// Make sure the error is written to the logger.
logrus.Error(err)
if !logrusToStderr() {
fmt.Fprintln(os.Stderr, err)
}
os.Exit(ret)
}
// setupSpec performs initial setup based on the cli.Context for the container
func setupSpec(context *cli.Context) (*specs.Spec, error) {
bundle := context.String("bundle")
if bundle != "" {
if err := os.Chdir(bundle); err != nil {
return nil, err
}
}
spec, err := loadSpec(specConfig)
if err != nil {
return nil, err
}
return spec, nil
}
func revisePidFile(context *cli.Context) error {
pidFile := context.String("pid-file")
if pidFile == "" {
return nil
}
// convert pid-file to an absolute path so we can write to the right
// file after chdir to bundle
pidFile, err := filepath.Abs(pidFile)
if err != nil {
return err
}
return context.Set("pid-file", pidFile)
}
// reviseRootDir convert the root to absolute path
func reviseRootDir(context *cli.Context) error {
root := context.GlobalString("root")
if root == "" {
return nil
}
root, err := filepath.Abs(root)
if err != nil {
return err
}
return context.GlobalSet("root", root)
}
// parseBoolOrAuto returns (nil, nil) if s is empty or "auto"
func parseBoolOrAuto(s string) (*bool, error) {
if s == "" || strings.ToLower(s) == "auto" {
return nil, nil
}
b, err := strconv.ParseBool(s)
return &b, err
}