github.com/rkt/rkt@v1.30.1-0.20200224141603-171c416fac02/stage1/enter_kvm/enter_kvm.go (about)

     1  // Copyright 2015 The rkt Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package main
    16  
    17  import (
    18  	"flag"
    19  	"fmt"
    20  	"io/ioutil"
    21  	"os"
    22  	"os/user"
    23  
    24  	rktlog "github.com/rkt/rkt/pkg/log"
    25  	"github.com/rkt/rkt/stage1/common/ssh"
    26  )
    27  
    28  var (
    29  	debug   bool
    30  	podPid  string
    31  	appName string
    32  	u, _    = user.Current()
    33  	log     *rktlog.Logger
    34  	diag    *rktlog.Logger
    35  )
    36  
    37  func init() {
    38  	flag.BoolVar(&debug, "debug", false, "Run in debug mode")
    39  	flag.StringVar(&podPid, "pid", "", "podPID")
    40  	flag.StringVar(&appName, "appname", "", "application to use")
    41  
    42  	log, diag, _ = rktlog.NewLogSet("kvm", false)
    43  }
    44  
    45  func getAppexecArgs() []string {
    46  	// Documentation/devel/stage1-implementors-guide.md#arguments-1
    47  	// also from ../enter/enter.c
    48  	if appName == "" {
    49  		return flag.Args()
    50  	}
    51  	args := []string{
    52  		"/enterexec",
    53  		fmt.Sprintf("/opt/stage2/%s/rootfs", appName),
    54  		"/", // as in ../enter/enter.c - this should be app.WorkingDirectory
    55  		fmt.Sprintf("/rkt/env/%s", appName),
    56  		u.Uid,
    57  		u.Gid,
    58  		"-e", /* entering phase */
    59  		"--",
    60  	}
    61  	return append(args, flag.Args()...)
    62  }
    63  
    64  func main() {
    65  	flag.Parse()
    66  
    67  	log.SetDebug(debug)
    68  	diag.SetDebug(debug)
    69  
    70  	if !debug {
    71  		diag.SetOutput(ioutil.Discard)
    72  	}
    73  
    74  	// ExecSSH() should return only with error
    75  	log.Error(ssh.ExecSSH(getAppexecArgs()))
    76  
    77  	os.Exit(254)
    78  }