github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/runsc/cmd/ps.go (about)

     1  // Copyright 2018 The gVisor 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 cmd
    16  
    17  import (
    18  	"context"
    19  	"fmt"
    20  
    21  	"github.com/google/subcommands"
    22  	"github.com/SagerNet/gvisor/pkg/sentry/control"
    23  	"github.com/SagerNet/gvisor/runsc/config"
    24  	"github.com/SagerNet/gvisor/runsc/container"
    25  	"github.com/SagerNet/gvisor/runsc/flag"
    26  )
    27  
    28  // PS implements subcommands.Command for the "ps" command.
    29  type PS struct {
    30  	format string
    31  }
    32  
    33  // Name implements subcommands.Command.Name.
    34  func (*PS) Name() string {
    35  	return "ps"
    36  }
    37  
    38  // Synopsis implements subcommands.Command.Synopsis.
    39  func (*PS) Synopsis() string {
    40  	return "ps displays the processes running inside a container"
    41  }
    42  
    43  // Usage implements subcommands.Command.Usage.
    44  func (*PS) Usage() string {
    45  	return "<container-id> [ps options]"
    46  }
    47  
    48  // SetFlags implements subcommands.Command.SetFlags.
    49  func (ps *PS) SetFlags(f *flag.FlagSet) {
    50  	f.StringVar(&ps.format, "format", "table", "output format. Select one of: table or json (default: table)")
    51  }
    52  
    53  // Execute implements subcommands.Command.Execute.
    54  func (ps *PS) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
    55  	if f.NArg() != 1 {
    56  		f.Usage()
    57  		return subcommands.ExitUsageError
    58  	}
    59  
    60  	id := f.Arg(0)
    61  	conf := args[0].(*config.Config)
    62  
    63  	c, err := container.Load(conf.RootDir, container.FullID{ContainerID: id}, container.LoadOpts{})
    64  	if err != nil {
    65  		Fatalf("loading sandbox: %v", err)
    66  	}
    67  	pList, err := c.Processes()
    68  	if err != nil {
    69  		Fatalf("getting processes for container: %v", err)
    70  	}
    71  
    72  	switch ps.format {
    73  	case "table":
    74  		fmt.Println(control.ProcessListToTable(pList))
    75  	case "json":
    76  		o, err := control.PrintPIDsJSON(pList)
    77  		if err != nil {
    78  			Fatalf("generating JSON: %v", err)
    79  		}
    80  		fmt.Println(o)
    81  	default:
    82  		Fatalf("unsupported format: %s", ps.format)
    83  	}
    84  
    85  	return subcommands.ExitSuccess
    86  }