package main import ( "fmt" "os" "path/filepath" "github.com/Sirupsen/logrus" "github.com/opencontainers/runtime-spec/specs-go" "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 } // 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) { // make sure the error is written to the logger logrus.Error(err) fmt.Fprintln(os.Stderr, err) os.Exit(1) } // 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) }