/
enter.go
55 lines (47 loc) · 1.74 KB
/
enter.go
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// Copyright 2014 The rkt Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//+build linux
package stage0
import (
"errors"
"fmt"
"os"
"path/filepath"
"syscall"
"github.com/appc/spec/schema/types"
"github.com/hashicorp/errwrap"
)
// Enter enters the pod/app by exec()ing the stage1's /enter similar to /init
// /enter can expect to have its CWD set to the app root.
// appName and command are supplied to /enter on argv followed by any arguments.
// stage1Path is the path of the stage1 rootfs
func Enter(cdir string, podPID int, appName types.ACName, stage1Path string, cmdline []string) error {
if err := os.Chdir(cdir); err != nil {
return errwrap.Wrap(errors.New("error changing to dir"), err)
}
ep, err := getStage1Entrypoint(cdir, enterEntrypoint)
if err != nil {
return errwrap.Wrap(errors.New("error determining 'enter' entrypoint"), err)
}
argv := []string{filepath.Join(stage1Path, ep)}
argv = append(argv, fmt.Sprintf("--pid=%d", podPID))
argv = append(argv, fmt.Sprintf("--appname=%s", appName.String()))
argv = append(argv, "--")
argv = append(argv, cmdline...)
if err := syscall.Exec(argv[0], argv, os.Environ()); err != nil {
return errwrap.Wrap(errors.New("error execing enter"), err)
}
// never reached
return nil
}