summaryrefslogtreecommitdiff
path: root/vendor/github.com/prometheus/procfs/proc.go
blob: 8a8430147ea5c231a3832a1e7de032b47b5fd97d (plain)
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
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
// Copyright 2018 The Prometheus 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.

package procfs

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"os"
	"strconv"
	"strings"

	"github.com/prometheus/procfs/internal/fs"
)

// Proc provides information about a running process.
type Proc struct {
	// The process ID.
	PID int

	fs fs.FS
}

// Procs represents a list of Proc structs.
type Procs []Proc

func (p Procs) Len() int           { return len(p) }
func (p Procs) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
func (p Procs) Less(i, j int) bool { return p[i].PID < p[j].PID }

// Self returns a process for the current process read via /proc/self.
func Self() (Proc, error) {
	fs, err := NewFS(DefaultMountPoint)
	if err != nil {
		return Proc{}, err
	}
	return fs.Self()
}

// NewProc returns a process for the given pid under /proc.
func NewProc(pid int) (Proc, error) {
	fs, err := NewFS(DefaultMountPoint)
	if err != nil {
		return Proc{}, err
	}
	return fs.Proc(pid)
}

// AllProcs returns a list of all currently available processes under /proc.
func AllProcs() (Procs, error) {
	fs, err := NewFS(DefaultMountPoint)
	if err != nil {
		return Procs{}, err
	}
	return fs.AllProcs()
}

// Self returns a process for the current process.
func (fs FS) Self() (Proc, error) {
	p, err := os.Readlink(fs.proc.Path("self"))
	if err != nil {
		return Proc{}, err
	}
	pid, err := strconv.Atoi(strings.Replace(p, string(fs.proc), "", -1))
	if err != nil {
		return Proc{}, err
	}
	return fs.Proc(pid)
}

// NewProc returns a process for the given pid.
//
// Deprecated: use fs.Proc() instead
func (fs FS) NewProc(pid int) (Proc, error) {
	return fs.Proc(pid)
}

// Proc returns a process for the given pid.
func (fs FS) Proc(pid int) (Proc, error) {
	if _, err := os.Stat(fs.proc.Path(strconv.Itoa(pid))); err != nil {
		return Proc{}, err
	}
	return Proc{PID: pid, fs: fs.proc}, nil
}

// AllProcs returns a list of all currently available processes.
func (fs FS) AllProcs() (Procs, error) {
	d, err := os.Open(fs.proc.Path())
	if err != nil {
		return Procs{}, err
	}
	defer d.Close()

	names, err := d.Readdirnames(-1)
	if err != nil {
		return Procs{}, fmt.Errorf("could not read %s: %s", d.Name(), err)
	}

	p := Procs{}
	for _, n := range names {
		pid, err := strconv.ParseInt(n, 10, 64)
		if err != nil {
			continue
		}
		p = append(p, Proc{PID: int(pid), fs: fs.proc})
	}

	return p, nil
}

// CmdLine returns the command line of a process.
func (p Proc) CmdLine() ([]string, error) {
	f, err := os.Open(p.path("cmdline"))
	if err != nil {
		return nil, err
	}
	defer f.Close()

	data, err := ioutil.ReadAll(f)
	if err != nil {
		return nil, err
	}

	if len(data) < 1 {
		return []string{}, nil
	}

	return strings.Split(string(bytes.TrimRight(data, string("\x00"))), string(byte(0))), nil
}

// Comm returns the command name of a process.
func (p Proc) Comm() (string, error) {
	f, err := os.Open(p.path("comm"))
	if err != nil {
		return "", err
	}
	defer f.Close()

	data, err := ioutil.ReadAll(f)
	if err != nil {
		return "", err
	}

	return strings.TrimSpace(string(data)), nil
}

// Executable returns the absolute path of the executable command of a process.
func (p Proc) Executable() (string, error) {
	exe, err := os.Readlink(p.path("exe"))
	if os.IsNotExist(err) {
		return "", nil
	}

	return exe, err
}

// Cwd returns the absolute path to the current working directory of the process.
func (p Proc) Cwd() (string, error) {
	wd, err := os.Readlink(p.path("cwd"))
	if os.IsNotExist(err) {
		return "", nil
	}

	return wd, err
}

// RootDir returns the absolute path to the process's root directory (as set by chroot)
func (p Proc) RootDir() (string, error) {
	rdir, err := os.Readlink(p.path("root"))
	if os.IsNotExist(err) {
		return "", nil
	}

	return rdir, err
}

// FileDescriptors returns the currently open file descriptors of a process.
func (p Proc) FileDescriptors() ([]uintptr, error) {
	names, err := p.fileDescriptors()
	if err != nil {
		return nil, err
	}

	fds := make([]uintptr, len(names))
	for i, n := range names {
		fd, err := strconv.ParseInt(n, 10, 32)
		if err != nil {
			return nil, fmt.Errorf("could not parse fd %s: %s", n, err)
		}
		fds[i] = uintptr(fd)
	}

	return fds, nil
}

// FileDescriptorTargets returns the targets of all file descriptors of a process.
// If a file descriptor is not a symlink to a file (like a socket), that value will be the empty string.
func (p Proc) FileDescriptorTargets() ([]string, error) {
	names, err := p.fileDescriptors()
	if err != nil {
		return nil, err
	}

	targets := make([]string, len(names))

	for i, name := range names {
		target, err := os.Readlink(p.path("fd", name))
		if err == nil {
			targets[i] = target
		}
	}

	return targets, nil
}

// FileDescriptorsLen returns the number of currently open file descriptors of
// a process.
func (p Proc) FileDescriptorsLen() (int, error) {
	fds, err := p.fileDescriptors()
	if err != nil {
		return 0, err
	}

	return len(fds), nil
}

// MountStats retrieves statistics and configuration for mount points in a
// process's namespace.
func (p Proc) MountStats() ([]*Mount, error) {
	f, err := os.Open(p.path("mountstats"))
	if err != nil {
		return nil, err
	}
	defer f.Close()

	return parseMountStats(f)
}

func (p Proc) fileDescriptors() ([]string, error) {
	d, err := os.Open(p.path("fd"))
	if err != nil {
		return nil, err
	}
	defer d.Close()

	names, err := d.Readdirnames(-1)
	if err != nil {
		return nil, fmt.Errorf("could not read %s: %s", d.Name(), err)
	}

	return names, nil
}

func (p Proc) path(pa ...string) string {
	return p.fs.Path(append([]string{strconv.Itoa(p.PID)}, pa...)...)
}