-
Notifications
You must be signed in to change notification settings - Fork 85
/
main.go
588 lines (512 loc) · 15.1 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
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
package main
import (
"bytes"
"crypto/tls"
"errors"
"flag"
"fmt"
"io"
"io/ioutil"
"log"
"net/http"
"os"
"regexp"
"strconv"
"strings"
"sync"
"text/template"
"time"
"golang.org/x/crypto/acme/autocert"
)
var (
httpFlag = flag.String("http", ":8080", "Serve HTTP at given address")
httpsFlag = flag.String("https", "", "Serve HTTPS at given address")
certFlag = flag.String("cert", "", "Use the provided TLS certificate")
keyFlag = flag.String("key", "", "Use the provided TLS key")
acmeFlag = flag.String("acme", "", "Auto-request TLS certs and store in given directory")
)
var httpClient = &http.Client{
Timeout: 10 * time.Second,
}
var bulkClient = &http.Client{
Timeout: 5 * time.Minute,
}
func newServer() *http.Server {
return &http.Server{
ReadTimeout: 30 * time.Second,
WriteTimeout: 5 * time.Minute,
}
}
func main() {
if err := run(); err != nil {
fmt.Fprintf(os.Stderr, "error: %v\n", err)
os.Exit(1)
}
}
func run() error {
flag.Parse()
http.HandleFunc("/", handler)
if *httpFlag == "" && *httpsFlag == "" {
return fmt.Errorf("must provide -http and/or -https")
}
if *acmeFlag != "" && *httpsFlag == "" {
return fmt.Errorf("cannot use -acme without -https")
}
if *acmeFlag != "" && (*certFlag != "" || *keyFlag != "") {
return fmt.Errorf("cannot provide -acme with -key or -cert")
}
if *acmeFlag == "" && (*httpsFlag != "" || *certFlag != "" || *keyFlag != "") && (*httpsFlag == "" || *certFlag == "" || *keyFlag == "") {
return fmt.Errorf("-https -cert and -key must be used together")
}
ch := make(chan error, 2)
if *acmeFlag != "" {
// So a potential error is seen upfront.
if err := os.MkdirAll(*acmeFlag, 0700); err != nil {
return err
}
}
if *httpFlag != "" && (*httpsFlag == "" || *acmeFlag == "") {
server := newServer()
server.Addr = *httpFlag
go func() {
ch <- server.ListenAndServe()
}()
}
if *httpsFlag != "" {
server := newServer()
server.Addr = *httpsFlag
if *acmeFlag != "" {
m := autocert.Manager{
ForceRSA: true,
Prompt: autocert.AcceptTOS,
Cache: autocert.DirCache(*acmeFlag),
RenewBefore: 24 * 30 * time.Hour,
HostPolicy: autocert.HostWhitelist(
"localhost",
"gopkg.in",
"p1.gopkg.in",
"p2.gopkg.in",
"p3.gopkg.in",
),
Email: "[email protected]",
}
server.TLSConfig = &tls.Config{
GetCertificate: m.GetCertificate,
}
go func() {
ch <- http.ListenAndServe(":80", m.HTTPHandler(nil))
}()
}
go func() {
ch <- server.ListenAndServeTLS(*certFlag, *keyFlag)
}()
}
return <-ch
}
var gogetTemplate = template.Must(template.New("").Parse(`
<html>
<head>
<meta name="go-import" content="{{.Original.GopkgRoot}} git https://{{.Original.GopkgRoot}}">
{{$root := .GitHubRoot}}{{$tree := .GitHubTree}}<meta name="go-source" content="{{.Original.GopkgRoot}} _ https://{{$root}}/tree/{{$tree}}{/dir} https://{{$root}}/blob/{{$tree}}{/dir}/{file}#L{line}">
</head>
<body>
go get {{.GopkgPath}}
</body>
</html>
`))
// Repo represents a source code repository on GitHub.
type Repo struct {
User string
Name string
SubPath string
OldFormat bool // The old /v2/pkg format.
MajorVersion Version
// FullVersion is the best version in AllVersions that matches MajorVersion.
// It defaults to InvalidVersion if there are no matches.
FullVersion Version
// AllVersions holds all versions currently available in the repository,
// either coming from branch names or from tag names. Version zero (v0)
// is only present in the list if it really exists in the repository.
AllVersions VersionList
// When there is a redirect in place, these are from the original request.
RedirUser string
RedirName string
}
// SetVersions records in the relevant fields the details about which
// package versions are available in the repository.
func (repo *Repo) SetVersions(all []Version) {
repo.AllVersions = all
for _, v := range repo.AllVersions {
if v.Major == repo.MajorVersion.Major && v.Unstable == repo.MajorVersion.Unstable && repo.FullVersion.Less(v) {
repo.FullVersion = v
}
}
}
// When there is a redirect in place, this will return the original repository
// but preserving the data for the new repository.
func (repo *Repo) Original() *Repo {
if repo.RedirName == "" {
return repo
}
orig := *repo
orig.User = repo.RedirUser
orig.Name = repo.RedirName
return &orig
}
type repoBase struct {
user string
name string
}
var redirect = map[repoBase]repoBase{
// https://github.com/go-fsnotify/fsnotify/issues/1
{"", "fsnotify"}: {"fsnotify", "fsnotify"},
}
const (
githubCom = "github.com"
gopkgIn = "gopkg.in"
)
// GitHubRoot returns the repository root at GitHub, without a schema.
func (repo *Repo) GitHubRoot() string {
if repo.User == "" {
return githubCom + "/go-" + repo.Name + "/" + repo.Name
} else {
return githubCom + "/" + repo.User + "/" + repo.Name
}
}
// GitHubTree returns the repository tree name at GitHub for the selected version.
func (repo *Repo) GitHubTree() string {
if repo.FullVersion == InvalidVersion {
return "master"
}
return repo.FullVersion.String()
}
// GopkgRoot returns the package root at gopkg.in, without a schema.
func (repo *Repo) GopkgRoot() string {
return repo.GopkgVersionRoot(repo.MajorVersion)
}
// GopkgPath returns the package path at gopkg.in, without a schema.
func (repo *Repo) GopkgPath() string {
return repo.GopkgVersionRoot(repo.MajorVersion) + repo.SubPath
}
// GopkgVersionRoot returns the package root in gopkg.in for the
// provided version, without a schema.
func (repo *Repo) GopkgVersionRoot(version Version) string {
version.Minor = -1
version.Patch = -1
v := version.String()
if repo.OldFormat {
if repo.User == "" {
return gopkgIn + "/" + v + "/" + repo.Name
} else {
return gopkgIn + "/" + repo.User + "/" + v + "/" + repo.Name
}
} else {
if repo.User == "" {
return gopkgIn + "/" + repo.Name + "." + v
} else {
return gopkgIn + "/" + repo.User + "/" + repo.Name + "." + v
}
}
}
var patternOld = regexp.MustCompile(`^/(?:([a-z0-9][-a-z0-9]+)/)?((?:v0|v[1-9][0-9]*)(?:\.0|\.[1-9][0-9]*){0,2}(?:-unstable)?)/([a-zA-Z][-a-zA-Z0-9]*)(?:\.git)?((?:/[a-zA-Z][-a-zA-Z0-9]*)*)$`)
var patternNew = regexp.MustCompile(`^/(?:([a-zA-Z0-9][-a-zA-Z0-9]+)/)?([a-zA-Z][-.a-zA-Z0-9]*)\.((?:v0|v[1-9][0-9]*)(?:\.0|\.[1-9][0-9]*){0,2}(?:-unstable)?)(?:\.git)?((?:/[a-zA-Z0-9][-.a-zA-Z0-9]*)*)$`)
func handler(resp http.ResponseWriter, req *http.Request) {
if req.URL.Path == "/health-check" {
resp.Write([]byte("ok"))
return
}
log.Printf("%s requested %s", req.RemoteAddr, req.URL)
if req.URL.Path == "/" {
resp.Header().Set("Location", "https://labix.org/gopkg.in")
resp.WriteHeader(http.StatusTemporaryRedirect)
return
}
m := patternNew.FindStringSubmatch(req.URL.Path)
oldFormat := false
if m == nil {
m = patternOld.FindStringSubmatch(req.URL.Path)
if m == nil {
sendNotFound(resp, "Unsupported URL pattern; see the documentation at gopkg.in for details.")
return
}
// "/v2/name" <= "/name.v2"
m[2], m[3] = m[3], m[2]
oldFormat = true
}
if strings.Contains(m[3], ".") {
sendNotFound(resp, "Import paths take the major version only (.%s instead of .%s); see docs at gopkg.in for the reasoning.",
m[3][:strings.Index(m[3], ".")], m[3])
return
}
repo := &Repo{
User: m[1],
Name: m[2],
SubPath: m[4],
OldFormat: oldFormat,
FullVersion: InvalidVersion,
}
if r, ok := redirect[repoBase{repo.User, repo.Name}]; ok {
repo.RedirUser, repo.RedirName = repo.User, repo.Name
repo.User, repo.Name = r.user, r.name
}
var ok bool
repo.MajorVersion, ok = parseVersion(m[3])
if !ok {
sendNotFound(resp, "Version %q improperly considered invalid; please warn the service maintainers.", m[3])
return
}
var changed []byte
var versions VersionList
original, err := fetchRefs(repo)
if err == ErrTimeout {
// Retry once.
httpClient.CloseIdleConnections()
original, err = fetchRefs(repo)
}
if err == nil {
changed, versions, err = changeRefs(original, repo.MajorVersion)
repo.SetVersions(versions)
}
switch err {
case nil:
// all ok
case ErrNoRepo:
sendNotFound(resp, "GitHub repository not found at https://%s", repo.GitHubRoot())
return
case ErrNoVersion:
major := repo.MajorVersion
suffix := ""
if major.Unstable {
major.Unstable = false
suffix = unstableSuffix
}
v := major.String()
sendNotFound(resp, `GitHub repository at https://%s has no branch or tag "%s%s", "%s.N%s" or "%s.N.M%s"`, repo.GitHubRoot(), v, suffix, v, suffix, v, suffix)
return
default:
resp.WriteHeader(http.StatusBadGateway)
resp.Write([]byte(fmt.Sprintf("Cannot obtain refs from GitHub: %v", err)))
return
}
if repo.SubPath == "/git-upload-pack" {
proxyUploadPack(resp, req, repo)
return
}
if repo.SubPath == "/info/refs" {
resp.Header().Set("Content-Type", "application/x-git-upload-pack-advertisement")
resp.Write(changed)
return
}
resp.Header().Set("Content-Type", "text/html")
if req.FormValue("go-get") == "1" {
// execute simple template when this is a go-get request
err = gogetTemplate.Execute(resp, repo)
if err != nil {
log.Printf("error executing go get template: %s\n", err)
}
return
}
renderPackagePage(resp, req, repo)
}
func sendNotFound(resp http.ResponseWriter, msg string, args ...interface{}) {
if len(args) > 0 {
msg = fmt.Sprintf(msg, args...)
}
resp.WriteHeader(http.StatusNotFound)
resp.Write([]byte(msg))
}
const refsSuffix = ".git/info/refs?service=git-upload-pack"
func proxyUploadPack(resp http.ResponseWriter, req *http.Request, repo *Repo) {
preq, err := http.NewRequest(req.Method, "https://"+repo.GitHubRoot()+"/git-upload-pack", req.Body)
if err != nil {
resp.WriteHeader(http.StatusInternalServerError)
resp.Write([]byte(fmt.Sprintf("Cannot create GitHub request: %v", err)))
return
}
preq.Header = req.Header
presp, err := bulkClient.Do(preq)
if err != nil {
resp.WriteHeader(http.StatusBadGateway)
resp.Write([]byte(fmt.Sprintf("Cannot obtain data pack from GitHub: %v", err)))
return
}
defer presp.Body.Close()
header := resp.Header()
for key, values := range presp.Header {
header[key] = values
}
resp.WriteHeader(presp.StatusCode)
// Ignore errors. Dropped connections are usual and will make this fail.
_, err = io.Copy(resp, presp.Body)
if err != nil {
log.Printf("Error copying data from GitHub: %v", err)
}
}
var (
ErrNoRepo = errors.New("repository not found in GitHub")
ErrNoVersion = errors.New("version reference not found in GitHub")
ErrTimeout = errors.New("timeout")
)
type refsCacheEntry struct {
refs []byte
timestamp time.Time
}
var refsCache map[string]*refsCacheEntry = make(map[string]*refsCacheEntry)
var refsCacheLock sync.RWMutex
const refsCacheTTL = 1 * time.Minute
func getRefs(root string) []byte {
refsCacheLock.RLock()
defer refsCacheLock.RUnlock()
if entry, ok := refsCache[root]; ok {
if time.Since(entry.timestamp) < refsCacheTTL {
return entry.refs
}
}
return nil
}
func setRefs(root string, refs []byte) {
refsCacheLock.Lock()
defer refsCacheLock.Unlock()
if entry, ok := refsCache[root]; ok {
if time.Since(entry.timestamp) < refsCacheTTL {
return
}
}
refsCache[root] = &refsCacheEntry{
refs: refs,
timestamp: time.Now(),
}
}
func fetchRefs(repo *Repo) (data []byte, err error) {
if refs := getRefs(repo.GitHubRoot()); refs != nil {
return refs, nil
}
resp, err := httpClient.Get("https://" + repo.GitHubRoot() + refsSuffix)
if err != nil {
if os.IsTimeout(err) {
return nil, ErrTimeout
}
return nil, fmt.Errorf("cannot talk to GitHub: %w", err)
}
defer resp.Body.Close()
switch resp.StatusCode {
case 200:
// ok
case 401, 404:
return nil, ErrNoRepo
default:
return nil, fmt.Errorf("error from GitHub: %v", resp.Status)
}
data, err = ioutil.ReadAll(resp.Body)
if err != nil {
return nil, fmt.Errorf("error reading from GitHub: %v", err)
}
setRefs(repo.GitHubRoot(), data)
return data, err
}
func changeRefs(data []byte, major Version) (changed []byte, versions VersionList, err error) {
var hlinei, hlinej int // HEAD reference line start/end
var mlinei, mlinej int // master reference line start/end
var vrefhash string
var vrefname string
var vrefv = InvalidVersion
// Record all available versions, the locations of the master and HEAD lines,
// and details of the best reference satisfying the requested major version.
versions = make([]Version, 0)
sdata := string(data)
for i, j := 0, 0; i < len(data); i = j {
size, err := strconv.ParseInt(sdata[i:i+4], 16, 32)
if err != nil {
return nil, nil, fmt.Errorf("cannot parse refs line size: %s", string(data[i:i+4]))
}
if size == 0 {
size = 4
}
j = i + int(size)
if j > len(sdata) {
return nil, nil, fmt.Errorf("incomplete refs data received from GitHub")
}
if sdata[0] == '#' {
continue
}
hashi := i + 4
hashj := strings.IndexByte(sdata[hashi:j], ' ')
if hashj < 0 || hashj != 40 {
continue
}
hashj += hashi
namei := hashj + 1
namej := strings.IndexAny(sdata[namei:j], "\n\x00")
if namej < 0 {
namej = j
} else {
namej += namei
}
name := sdata[namei:namej]
if name == "HEAD" {
hlinei = i
hlinej = j
}
if name == "refs/heads/master" {
mlinei = i
mlinej = j
}
if strings.HasPrefix(name, "refs/heads/v") || strings.HasPrefix(name, "refs/tags/v") {
// Annotated tag is peeled off and overrides the same version just parsed.
name = strings.TrimSuffix(name, "^{}")
v, ok := parseVersion(name[strings.IndexByte(name, 'v'):])
if ok && major.Contains(v) && (v == vrefv || !vrefv.IsValid() || vrefv.Less(v)) {
vrefv = v
vrefhash = sdata[hashi:hashj]
vrefname = name
}
if ok {
versions = append(versions, v)
}
}
}
// If there were absolutely no versions, and v0 was requested, accept the master as-is.
if len(versions) == 0 && major == (Version{0, -1, -1, false}) {
return data, nil, nil
}
// If the file has no HEAD line or the version was not found, report as unavailable.
if hlinei == 0 || vrefhash == "" {
return nil, nil, ErrNoVersion
}
var buf bytes.Buffer
buf.Grow(len(data) + 256)
// Copy the header as-is.
buf.Write(data[:hlinei])
// Extract the original capabilities.
caps := ""
if i := strings.Index(sdata[hlinei:hlinej], "\x00"); i > 0 {
caps = strings.Replace(sdata[hlinei+i+1:hlinej-1], "symref=", "oldref=", -1)
}
// Insert the HEAD reference line with the right hash and a proper symref capability.
var line string
if strings.HasPrefix(vrefname, "refs/heads/") {
if caps == "" {
line = fmt.Sprintf("%s HEAD\x00symref=HEAD:%s\n", vrefhash, vrefname)
} else {
line = fmt.Sprintf("%s HEAD\x00symref=HEAD:%s %s\n", vrefhash, vrefname, caps)
}
} else {
if caps == "" {
line = fmt.Sprintf("%s HEAD\n", vrefhash)
} else {
line = fmt.Sprintf("%s HEAD\x00%s\n", vrefhash, caps)
}
}
fmt.Fprintf(&buf, "%04x%s", 4+len(line), line)
// Insert the master reference line.
line = fmt.Sprintf("%s refs/heads/master\n", vrefhash)
fmt.Fprintf(&buf, "%04x%s", 4+len(line), line)
// Append the rest, dropping the original master line if necessary.
if mlinei > 0 {
buf.Write(data[hlinej:mlinei])
buf.Write(data[mlinej:])
} else {
buf.Write(data[hlinej:])
}
return buf.Bytes(), versions, nil
}