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
|
package main
import (
"bufio"
"context"
"fmt"
"io"
"os"
"os/exec"
"sync"
"gitlab.com/gitlab-org/gitlab-runner/common"
"gitlab.com/gitlab-org/gitlab-runner/helpers"
)
var images = []string{
common.TestAlpineImage,
common.TestAlpineNoRootImage,
common.TestDockerGitImage,
common.TestDockerDindImage,
}
type rewriter struct {
ctx context.Context
prefix string
input *bufio.Reader
}
func (rw *rewriter) watch() {
for {
select {
case <-rw.ctx.Done():
return
case err := <-rw.rewriteInput():
if err != nil {
rw.writeToOutput(fmt.Sprintf("Error while reading command output: %v", err))
return
}
}
}
}
func (rw *rewriter) rewriteInput() <-chan error {
e := make(chan error)
go func() {
line, err := rw.input.ReadString('\n')
if err == nil || err == io.EOF {
rw.writeToOutput(line)
e <- nil
return
}
e <- err
}()
return e
}
func (rw *rewriter) writeToOutput(line string) {
fmt.Printf("%s[%s]%s %s", helpers.ANSI_YELLOW, rw.prefix, helpers.ANSI_RESET, line)
}
func newRewriter(ctx context.Context, prefix string) io.Writer {
pr, pw, err := os.Pipe()
if err != nil {
panic(err)
}
w := &rewriter{
ctx: ctx,
prefix: prefix,
input: bufio.NewReader(pr),
}
go w.watch()
return pw
}
func pullImage(wg *sync.WaitGroup, name string) {
ctx, cancel := context.WithCancel(context.Background())
defer func() {
cancel()
wg.Done()
}()
output := newRewriter(ctx, name)
cmd := exec.Command("docker", "pull", name)
cmd.Stdout = output
cmd.Stderr = output
err := cmd.Run()
if err != nil {
panic(err)
}
}
func main() {
wg := new(sync.WaitGroup)
for _, image := range images {
wg.Add(1)
go pullImage(wg, image)
}
wg.Wait()
}
|
