-
Notifications
You must be signed in to change notification settings - Fork 12
/
main.go
279 lines (252 loc) · 7.59 KB
/
main.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
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
268
269
270
271
272
273
274
275
276
277
278
279
package main
import (
"context"
"fmt"
"io"
"log/slog"
"net/http"
"os"
"strings"
"github.com/google/go-containerregistry/pkg/name"
v1 "github.com/google/go-containerregistry/pkg/v1"
"github.com/google/go-containerregistry/pkg/v1/empty"
"github.com/google/go-containerregistry/pkg/v1/mutate"
"github.com/google/go-containerregistry/pkg/v1/remote"
"github.com/google/go-containerregistry/pkg/v1/tarball"
"github.com/google/go-containerregistry/pkg/v1/types"
"github.com/imjasonh/gcpslog"
"github.com/imjasonh/kontain.me/pkg/serve"
"golang.org/x/sync/errgroup"
)
func main() {
ctx := context.Background()
st, err := serve.NewStorage(ctx)
if err != nil {
slog.ErrorContext(ctx, "serve.NewStorage", "err", err)
os.Exit(1)
}
http.Handle("/v2/", gcpslog.WithCloudTraceContext(&server{storage: st}))
http.Handle("/", http.RedirectHandler("https://github.com/imjasonh/kontain.me/blob/main/cmd/flatten", http.StatusSeeOther))
port := os.Getenv("PORT")
if port == "" {
port = "8080"
slog.InfoContext(ctx, "Defaulting port", "port", port)
}
slog.InfoContext(ctx, "Listening...", "port", port)
slog.ErrorContext(ctx, "ListenAndServe", "err", http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
}
type server struct{ storage *serve.Storage }
func (s *server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
path := strings.TrimPrefix(r.URL.String(), "/v2/")
switch {
case path == "":
// API Version check.
w.Header().Set("Docker-Distribution-API-Version", "registry/2.0")
return
case strings.Contains(path, "/blobs/"),
strings.Contains(path, "/manifests/sha256:"):
// Extract requested blob digest and redirect to serve it from GCS.
// If it doesn't exist, this will return 404.
parts := strings.Split(r.URL.Path, "/")
digest := parts[len(parts)-1]
serve.Blob(w, r, digest)
case strings.Contains(path, "/manifests/"):
s.serveFlattenManifest(w, r)
default:
serve.Error(w, serve.ErrNotFound)
}
}
var acceptableMediaTypes = map[types.MediaType]bool{
types.DockerManifestSchema2: true,
types.DockerManifestList: true,
types.OCIImageIndex: true,
types.OCIManifestSchema1: true,
}
func cacheKey(orig string) string { return fmt.Sprintf("flatten-%s", orig) }
// flatten.kontain.me/ubuntu -> flatten ubuntu and serve
func (s *server) serveFlattenManifest(w http.ResponseWriter, r *http.Request) {
ctx := r.Context()
path := strings.TrimPrefix(r.URL.Path, "/v2/")
parts := strings.Split(path, "/")
refstr := strings.Join(parts[:len(parts)-2], "/")
tagOrDigest := parts[len(parts)-1]
if strings.HasPrefix(tagOrDigest, "sha256:") {
refstr += "@" + tagOrDigest
} else {
refstr += ":" + tagOrDigest
}
for strings.HasPrefix(refstr, "flatten.kontain.me/") {
refstr = strings.TrimPrefix(refstr, "flatten.kontain.me/")
}
ref, err := name.ParseReference(refstr)
if err != nil {
slog.ErrorContext(ctx, "name.ParseReference", "ref", refstr, "err", err)
serve.Error(w, err)
return
}
var idx v1.ImageIndex
var img v1.Image
var ck string
// Determine whether the ref is for an image or index.
d, err := remote.Head(ref, remote.WithContext(ctx))
if err != nil {
slog.ErrorContext(ctx, "remote.Head", "ref", refstr, "err", err)
var h v1.Hash
// HEAD failed, let's figure out if it was an index or image by doing GETs.
idx, err = remote.Index(ref, remote.WithContext(ctx))
if err != nil {
slog.ErrorContext(ctx, "remote.Index", "ref", refstr, "err", err)
img, err = remote.Image(ref, remote.WithContext(ctx))
if err != nil {
slog.ErrorContext(ctx, "remote.Image", "ref", refstr, "err", err)
serve.Error(w, err)
return
}
}
if idx != nil {
h, err = idx.Digest()
} else if img != nil {
h, err = img.Digest()
}
if err != nil {
slog.ErrorContext(ctx, "Digest()", "ref", refstr, "err", err)
serve.Error(w, err)
return
}
// Check if we have a flattened manifest cached (since HEAD failed
// before), and if so serve it directly.
ck = cacheKey(h.String())
if _, err := s.storage.BlobExists(ctx, ck); err == nil {
slog.InfoContext(ctx, "serving cached manifest", "ck", ck)
serve.Blob(w, r, ck)
return
}
} else {
if !acceptableMediaTypes[d.MediaType] {
err = fmt.Errorf("unknown media type: %s", d.MediaType)
slog.ErrorContext(ctx, "unknown media type", "ref", refstr, "err", err)
serve.Error(w, err)
return
}
// Check if we have a flattened manifest cached, and if so serve it
// directly.
ck = cacheKey(d.Digest.String())
if _, err := s.storage.BlobExists(ctx, ck); err == nil {
slog.InfoContext(ctx, "serving cached manifest", "ck", ck)
serve.Blob(w, r, ck)
return
}
switch d.MediaType {
case types.OCIImageIndex, types.DockerManifestList:
idx, err = remote.Index(ref, remote.WithContext(ctx))
if err != nil {
err = fmt.Errorf("remote.Index: %v", err)
slog.ErrorContext(ctx, "remote.Index", "ref", refstr, "err", err)
serve.Error(w, err)
return
}
case types.OCIManifestSchema1, types.DockerManifestSchema2:
img, err = remote.Image(ref, remote.WithContext(ctx))
if err != nil {
err = fmt.Errorf("remote.Image: %v", err)
slog.ErrorContext(ctx, "remote.Image", "ref", refstr, "err", err)
serve.Error(w, err)
return
}
}
}
if idx != nil {
fidx, err := s.flattenIndex(ctx, idx)
if err != nil {
serve.Error(w, err)
return
}
if err := s.storage.ServeIndex(w, r, fidx, ck); err != nil {
slog.ErrorContext(ctx, "storage.ServeIndex", "err", err)
serve.Error(w, err)
return
}
return
}
if img != nil {
fimg, err := s.flatten(ctx, img)
if err != nil {
serve.Error(w, err)
return
}
if err := s.storage.ServeManifest(w, r, fimg, ck); err != nil {
slog.ErrorContext(ctx, "storage.ServeManifest", "err", err)
serve.Error(w, err)
return
}
return
}
}
func (s *server) flattenIndex(ctx context.Context, idx v1.ImageIndex) (v1.ImageIndex, error) {
im, err := idx.IndexManifest()
if err != nil {
slog.ErrorContext(ctx, "idx.IndexManifest", "err", err)
return nil, err
}
// Flatten each image in the manifest.
var g errgroup.Group
adds := make([]mutate.IndexAddendum, len(im.Manifests))
for i, m := range im.Manifests {
i, m := i, m
g.Go(func() error {
img, err := idx.Image(m.Digest)
if err != nil {
slog.ErrorContext(ctx, "idx.Image", "err", err)
return err
}
fimg, err := s.flatten(ctx, img)
if err != nil {
return err
}
m.Digest, err = fimg.Digest()
if err != nil {
slog.ErrorContext(ctx, "fimg.Digest", "err", err)
return err
}
adds[i] = mutate.IndexAddendum{
Add: fimg,
Descriptor: m,
}
return nil
})
}
if err := g.Wait(); err != nil {
slog.ErrorContext(ctx, "g.Wait", "err", err)
return nil, err
}
return mutate.AppendManifests(empty.Index, adds...), nil
}
func (s *server) flatten(ctx context.Context, img v1.Image) (v1.Image, error) {
l, err := tarball.LayerFromOpener(func() (io.ReadCloser, error) { return mutate.Extract(img), nil })
if err != nil {
slog.ErrorContext(ctx, "tarball.LayerFromOpener", "err", err)
return nil, err
}
fimg, err := mutate.AppendLayers(empty.Image, l)
if err != nil {
slog.ErrorContext(ctx, "mutate.AppendLayers", "err", err)
return nil, err
}
// Copy over basic information from original config file.
ocf, err := img.ConfigFile()
if err != nil {
slog.ErrorContext(ctx, "img.ConfigFile", "err", err)
return nil, err
}
ncf, err := fimg.ConfigFile()
if err != nil {
slog.ErrorContext(ctx, "fimg.ConfigFile", "err", err)
return nil, err
}
cf := ncf.DeepCopy()
cf.Architecture = ocf.Architecture
cf.OS = ocf.OS
cf.OSVersion = ocf.OSVersion
cf.Config = ocf.Config
return mutate.ConfigFile(fimg, cf)
}