-
Notifications
You must be signed in to change notification settings - Fork 1
/
exec.go
200 lines (167 loc) · 5.32 KB
/
exec.go
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
/*
Copyright 2014 The Kubernetes 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 exec
import (
"io"
osexec "os/exec"
"syscall"
"time"
)
// ErrExecutableNotFound is returned if the executable is not found.
var ErrExecutableNotFound = osexec.ErrNotFound
// Interface is an interface that presents a subset of the os/exec API. Use this
// when you want to inject fakeable/mockable exec behavior.
type Interface interface {
// Command returns a Cmd instance which can be used to run a single command.
// This follows the pattern of package os/exec.
Command(cmd string, args ...string) Cmd
// LookPath wraps os/exec.LookPath
LookPath(file string) (string, error)
}
// Cmd is an interface that presents an API that is very similar to Cmd from os/exec.
// As more functionality is needed, this can grow. Since Cmd is a struct, we will have
// to replace fields with get/set method pairs.
type Cmd interface {
// Run runs the command to the completion.
Run() error
// CombinedOutput runs the command and returns its combined standard output
// and standard error. This follows the pattern of package os/exec.
CombinedOutput() ([]byte, error)
// Output runs the command and returns standard output, but not standard err
Output() ([]byte, error)
SetDir(dir string)
SetStdin(in io.Reader)
SetStdout(out io.Writer)
SetStderr(out io.Writer)
// Stops the command by sending SIGTERM. It is not guaranteed the
// process will stop before this function returns. If the process is not
// responding, an internal timer function will send a SIGKILL to force
// terminate after 10 seconds.
Stop()
}
// ExitError is an interface that presents an API similar to os.ProcessState, which is
// what ExitError from os/exec is. This is designed to make testing a bit easier and
// probably loses some of the cross-platform properties of the underlying library.
type ExitError interface {
String() string
Error() string
Exited() bool
ExitStatus() int
}
// Implements Interface in terms of really exec()ing.
type executor struct{}
// New returns a new Interface which will os/exec to run commands.
func New() Interface {
return &executor{}
}
// Command is part of the Interface interface.
func (executor *executor) Command(cmd string, args ...string) Cmd {
return (*cmdWrapper)(osexec.Command(cmd, args...))
}
// LookPath is part of the Interface interface
func (executor *executor) LookPath(file string) (string, error) {
return osexec.LookPath(file)
}
// Wraps exec.Cmd so we can capture errors.
type cmdWrapper osexec.Cmd
func (cmd *cmdWrapper) SetDir(dir string) {
cmd.Dir = dir
}
func (cmd *cmdWrapper) SetStdin(in io.Reader) {
cmd.Stdin = in
}
func (cmd *cmdWrapper) SetStdout(out io.Writer) {
cmd.Stdout = out
}
func (cmd *cmdWrapper) SetStderr(out io.Writer) {
cmd.Stderr = out
}
// Run is part of the Cmd interface.
func (cmd *cmdWrapper) Run() error {
return (*osexec.Cmd)(cmd).Run()
}
// CombinedOutput is part of the Cmd interface.
func (cmd *cmdWrapper) CombinedOutput() ([]byte, error) {
out, err := (*osexec.Cmd)(cmd).CombinedOutput()
if err != nil {
return out, handleError(err)
}
return out, nil
}
func (cmd *cmdWrapper) Output() ([]byte, error) {
out, err := (*osexec.Cmd)(cmd).Output()
if err != nil {
return out, handleError(err)
}
return out, nil
}
// Stop is part of the Cmd interface.
func (cmd *cmdWrapper) Stop() {
c := (*osexec.Cmd)(cmd)
if c.ProcessState.Exited() {
return
}
c.Process.Signal(syscall.SIGTERM)
time.AfterFunc(10*time.Second, func() {
if c.ProcessState.Exited() {
return
}
c.Process.Signal(syscall.SIGKILL)
})
}
func handleError(err error) error {
if ee, ok := err.(*osexec.ExitError); ok {
// Force a compile fail if exitErrorWrapper can't convert to ExitError.
var x ExitError = &ExitErrorWrapper{ee}
return x
}
if ee, ok := err.(*osexec.Error); ok {
if ee.Err == osexec.ErrNotFound {
return ErrExecutableNotFound
}
}
return err
}
// ExitErrorWrapper is an implementation of ExitError in terms of os/exec ExitError.
// Note: standard exec.ExitError is type *os.ProcessState, which already implements Exited().
type ExitErrorWrapper struct {
*osexec.ExitError
}
var _ ExitError = ExitErrorWrapper{}
// ExitStatus is part of the ExitError interface.
func (eew ExitErrorWrapper) ExitStatus() int {
ws, ok := eew.Sys().(syscall.WaitStatus)
if !ok {
panic("can't call ExitStatus() on a non-WaitStatus exitErrorWrapper")
}
return ws.ExitStatus()
}
// CodeExitError is an implementation of ExitError consisting of an error object
// and an exit code (the upper bits of os.exec.ExitStatus).
type CodeExitError struct {
Err error
Code int
}
var _ ExitError = CodeExitError{}
func (e CodeExitError) Error() string {
return e.Err.Error()
}
func (e CodeExitError) String() string {
return e.Err.Error()
}
func (e CodeExitError) Exited() bool {
return true
}
func (e CodeExitError) ExitStatus() int {
return e.Code
}