/
fetch.go
172 lines (142 loc) · 3.31 KB
/
fetch.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
package blob
import (
"crypto/sha256"
"fmt"
"io"
"io/fs"
"log"
"net/http"
"net/url"
"os"
"path"
"github.com/BurntSushi/toml"
"github.com/pkg/errors"
"github.com/pivotal/kpack/pkg/archive"
)
var unexpectedBlobTypeError = errors.New("unexpected blob file type, must be one of .zip, .tar.gz, .tar, .jar")
type Fetcher struct {
Logger *log.Logger
}
func (f *Fetcher) Fetch(dir string, blobURL string, stripComponents int, metadataDir string) error {
u, err := url.Parse(blobURL)
if err != nil {
return err
}
f.Logger.Printf("Downloading %s%s...", u.Host, u.Path)
file, err := downloadBlob(blobURL)
if err != nil {
return err
}
defer os.RemoveAll(file.Name())
mediaType, err := classifyFile(file)
if err != nil {
return err
}
checksum, err := sha256sum(file)
if err != nil {
return err
}
switch mediaType {
case "application/zip":
var info fs.FileInfo
info, err = file.Stat()
if err != nil {
return err
}
err = archive.ExtractZip(file, info.Size(), dir, stripComponents)
case "application/x-gzip":
err = archive.ExtractTarGZ(file, dir, stripComponents)
case "application/octet-stream":
if !archive.IsTar(file.Name()) {
return unexpectedBlobTypeError
}
err = archive.ExtractTar(file, dir, stripComponents)
default:
return unexpectedBlobTypeError
}
if err != nil {
return err
}
projectMetadataFile, err := os.Create(path.Join(metadataDir, "project-metadata.toml"))
if err != nil {
return errors.Wrapf(err, "invalid metadata destination '%s/project-metadata.toml' for blob: %s", metadataDir, blobURL)
}
defer projectMetadataFile.Close()
projectMd := Project{
Source: Source{
Type: "blob",
Metadata: Metadata{
Url: blobURL,
},
Version: Version{
SHA256: checksum,
},
},
}
if err := toml.NewEncoder(projectMetadataFile).Encode(projectMd); err != nil {
return errors.Wrapf(err, "invalid metadata destination '%s/project-metadata.toml' for blob: %s", metadataDir, blobURL)
}
f.Logger.Printf("Successfully downloaded %s%s in path %q", u.Host, u.Path, dir)
return nil
}
func downloadBlob(blobURL string) (*os.File, error) {
resp, err := http.Get(blobURL)
if err != nil {
return nil, err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return nil, errors.Errorf("failed to get blob %s", blobURL)
}
file, err := os.CreateTemp("", "")
if err != nil {
return nil, err
}
_, err = io.Copy(file, resp.Body)
if err != nil {
return nil, err
}
_, err = file.Seek(0, 0)
if err != nil {
return nil, err
}
return file, nil
}
func classifyFile(reader io.ReadSeeker) (string, error) {
buf := make([]byte, 512)
_, err := reader.Read(buf)
if err != nil {
return "", err
}
_, err = reader.Seek(0, 0)
if err != nil {
return "", err
}
return http.DetectContentType(buf), nil
}
func sha256sum(reader io.ReadSeeker) (string, error) {
hash := sha256.New()
_, err := io.Copy(hash, reader)
if err != nil {
return "", err
}
_, err = reader.Seek(0, 0)
if err != nil {
return "", err
}
return fmt.Sprintf("%x", hash.Sum(nil)), nil
}
type Project struct {
Source Source `toml:"source"`
}
type Source struct {
Type string `toml:"type"`
Metadata Metadata `toml:"metadata"`
Version Version `toml:"version"`
}
type Metadata struct {
Url string `toml:"url"`
}
type Version struct {
SHA256 string `toml:"sha256sum"`
}