File: exec.go

package info (click to toggle)
runc 1.0.0~rc9+dfsg1-1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, sid
  • size: 1,996 kB
  • sloc: sh: 1,422; ansic: 1,008; makefile: 116
file content (235 lines) | stat: -rw-r--r-- 6,286 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
// +build linux

package main

import (
	"encoding/json"
	"fmt"
	"os"
	"strconv"
	"strings"

	"github.com/opencontainers/runc/libcontainer"
	"github.com/opencontainers/runc/libcontainer/utils"
	"github.com/opencontainers/runtime-spec/specs-go"
	"github.com/urfave/cli"
)

var execCommand = cli.Command{
	Name:  "exec",
	Usage: "execute new process inside the container",
	ArgsUsage: `<container-id> <command> [command options]  || -p process.json <container-id>

Where "<container-id>" is the name for the instance of the container and
"<command>" is the command to be executed in the container.
"<command>" can't be empty unless a "-p" flag provided.

EXAMPLE:
For example, if the container is configured to run the linux ps command the
following will output a list of processes running in the container:

       # runc exec <container-id> ps`,
	Flags: []cli.Flag{
		cli.StringFlag{
			Name:  "console-socket",
			Usage: "path to an AF_UNIX socket which will receive a file descriptor referencing the master end of the console's pseudoterminal",
		},
		cli.StringFlag{
			Name:  "cwd",
			Usage: "current working directory in the container",
		},
		cli.StringSliceFlag{
			Name:  "env, e",
			Usage: "set environment variables",
		},
		cli.BoolFlag{
			Name:  "tty, t",
			Usage: "allocate a pseudo-TTY",
		},
		cli.StringFlag{
			Name:  "user, u",
			Usage: "UID (format: <uid>[:<gid>])",
		},
		cli.Int64SliceFlag{
			Name:  "additional-gids, g",
			Usage: "additional gids",
		},
		cli.StringFlag{
			Name:  "process, p",
			Usage: "path to the process.json",
		},
		cli.BoolFlag{
			Name:  "detach,d",
			Usage: "detach from the container's process",
		},
		cli.StringFlag{
			Name:  "pid-file",
			Value: "",
			Usage: "specify the file to write the process id to",
		},
		cli.StringFlag{
			Name:  "process-label",
			Usage: "set the asm process label for the process commonly used with selinux",
		},
		cli.StringFlag{
			Name:  "apparmor",
			Usage: "set the apparmor profile for the process",
		},
		cli.BoolFlag{
			Name:  "no-new-privs",
			Usage: "set the no new privileges value for the process",
		},
		cli.StringSliceFlag{
			Name:  "cap, c",
			Value: &cli.StringSlice{},
			Usage: "add a capability to the bounding set for the process",
		},
		cli.BoolFlag{
			Name:   "no-subreaper",
			Usage:  "disable the use of the subreaper used to reap reparented processes",
			Hidden: true,
		},
		cli.IntFlag{
			Name:  "preserve-fds",
			Usage: "Pass N additional file descriptors to the container (stdio + $LISTEN_FDS + N in total)",
		},
	},
	Action: func(context *cli.Context) error {
		if err := checkArgs(context, 1, minArgs); err != nil {
			return err
		}
		if err := revisePidFile(context); err != nil {
			return err
		}
		status, err := execProcess(context)
		if err == nil {
			os.Exit(status)
		}
		return fmt.Errorf("exec failed: %v", err)
	},
	SkipArgReorder: true,
}

func execProcess(context *cli.Context) (int, error) {
	container, err := getContainer(context)
	if err != nil {
		return -1, err
	}
	status, err := container.Status()
	if err != nil {
		return -1, err
	}
	if status == libcontainer.Stopped {
		return -1, fmt.Errorf("cannot exec a container that has stopped")
	}
	path := context.String("process")
	if path == "" && len(context.Args()) == 1 {
		return -1, fmt.Errorf("process args cannot be empty")
	}
	detach := context.Bool("detach")
	state, err := container.State()
	if err != nil {
		return -1, err
	}
	bundle := utils.SearchLabels(state.Config.Labels, "bundle")
	p, err := getProcess(context, bundle)
	if err != nil {
		return -1, err
	}

	logLevel := "info"
	if context.GlobalBool("debug") {
		logLevel = "debug"
	}

	r := &runner{
		enableSubreaper: false,
		shouldDestroy:   false,
		container:       container,
		consoleSocket:   context.String("console-socket"),
		detach:          detach,
		pidFile:         context.String("pid-file"),
		action:          CT_ACT_RUN,
		init:            false,
		preserveFDs:     context.Int("preserve-fds"),
		logLevel:        logLevel,
	}
	return r.run(p)
}

func getProcess(context *cli.Context, bundle string) (*specs.Process, error) {
	if path := context.String("process"); path != "" {
		f, err := os.Open(path)
		if err != nil {
			return nil, err
		}
		defer f.Close()
		var p specs.Process
		if err := json.NewDecoder(f).Decode(&p); err != nil {
			return nil, err
		}
		return &p, validateProcessSpec(&p)
	}
	// process via cli flags
	if err := os.Chdir(bundle); err != nil {
		return nil, err
	}
	spec, err := loadSpec(specConfig)
	if err != nil {
		return nil, err
	}
	p := spec.Process
	p.Args = context.Args()[1:]
	// override the cwd, if passed
	if context.String("cwd") != "" {
		p.Cwd = context.String("cwd")
	}
	if ap := context.String("apparmor"); ap != "" {
		p.ApparmorProfile = ap
	}
	if l := context.String("process-label"); l != "" {
		p.SelinuxLabel = l
	}
	if caps := context.StringSlice("cap"); len(caps) > 0 {
		for _, c := range caps {
			p.Capabilities.Bounding = append(p.Capabilities.Bounding, c)
			p.Capabilities.Inheritable = append(p.Capabilities.Inheritable, c)
			p.Capabilities.Effective = append(p.Capabilities.Effective, c)
			p.Capabilities.Permitted = append(p.Capabilities.Permitted, c)
			p.Capabilities.Ambient = append(p.Capabilities.Ambient, c)
		}
	}
	// append the passed env variables
	p.Env = append(p.Env, context.StringSlice("env")...)

	// set the tty
	if context.IsSet("tty") {
		p.Terminal = context.Bool("tty")
	}
	if context.IsSet("no-new-privs") {
		p.NoNewPrivileges = context.Bool("no-new-privs")
	}
	// override the user, if passed
	if context.String("user") != "" {
		u := strings.SplitN(context.String("user"), ":", 2)
		if len(u) > 1 {
			gid, err := strconv.Atoi(u[1])
			if err != nil {
				return nil, fmt.Errorf("parsing %s as int for gid failed: %v", u[1], err)
			}
			p.User.GID = uint32(gid)
		}
		uid, err := strconv.Atoi(u[0])
		if err != nil {
			return nil, fmt.Errorf("parsing %s as int for uid failed: %v", u[0], err)
		}
		p.User.UID = uint32(uid)
	}
	for _, gid := range context.Int64Slice("additional-gids") {
		if gid < 0 {
			return nil, fmt.Errorf("additional-gids must be a positive number %d", gid)
		}
		p.User.AdditionalGids = append(p.User.AdditionalGids, uint32(gid))
	}
	return p, validateProcessSpec(p)
}