Files
runc/utils.go
Aleksa Sarai d2f49696b0 runc: add support for rootless containers
This enables the support for the rootless container mode. There are many
restrictions on what rootless containers can do, so many different runC
commands have been disabled:

* runc checkpoint
* runc events
* runc pause
* runc ps
* runc restore
* runc resume
* runc update

The following commands work:

* runc create
* runc delete
* runc exec
* runc kill
* runc list
* runc run
* runc spec
* runc state

In addition, any specification options that imply joining cgroups have
also been disabled. This is due to support for unprivileged subtree
management not being available from Linux upstream.

Signed-off-by: Aleksa Sarai <asarai@suse.de>
2017-03-23 20:45:24 +11:00

83 lines
1.8 KiB
Go

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)
}