-
-
Notifications
You must be signed in to change notification settings - Fork 4.1k
/
tplcontext.go
511 lines (438 loc) · 13.7 KB
/
tplcontext.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
// Copyright 2015 Matthew Holt and The Caddy 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 templates
import (
"bytes"
"fmt"
"io"
"io/fs"
"net"
"net/http"
"os"
"path"
"strconv"
"strings"
"sync"
"text/template"
"time"
"github.com/Masterminds/sprig/v3"
chromahtml "github.com/alecthomas/chroma/v2/formatters/html"
"github.com/dustin/go-humanize"
"github.com/yuin/goldmark"
highlighting "github.com/yuin/goldmark-highlighting/v2"
"github.com/yuin/goldmark/extension"
"github.com/yuin/goldmark/parser"
gmhtml "github.com/yuin/goldmark/renderer/html"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
)
// TemplateContext is the TemplateContext with which HTTP templates are executed.
type TemplateContext struct {
Root http.FileSystem
Req *http.Request
Args []any // defined by arguments to funcInclude
RespHeader WrappedHeader
CustomFuncs []template.FuncMap // functions added by plugins
config *Templates
tpl *template.Template
}
// NewTemplate returns a new template intended to be evaluated with this
// context, as it is initialized with configuration from this context.
func (c *TemplateContext) NewTemplate(tplName string) *template.Template {
c.tpl = template.New(tplName)
// customize delimiters, if applicable
if c.config != nil && len(c.config.Delimiters) == 2 {
c.tpl.Delims(c.config.Delimiters[0], c.config.Delimiters[1])
}
// add sprig library
c.tpl.Funcs(sprigFuncMap)
// add all custom functions
for _, funcMap := range c.CustomFuncs {
c.tpl.Funcs(funcMap)
}
// add our own library
c.tpl.Funcs(template.FuncMap{
"include": c.funcInclude,
"readFile": c.funcReadFile,
"import": c.funcImport,
"httpInclude": c.funcHTTPInclude,
"stripHTML": c.funcStripHTML,
"markdown": c.funcMarkdown,
"splitFrontMatter": c.funcSplitFrontMatter,
"listFiles": c.funcListFiles,
"fileStat": c.funcFileStat,
"env": c.funcEnv,
"placeholder": c.funcPlaceholder,
"fileExists": c.funcFileExists,
"httpError": c.funcHTTPError,
"humanize": c.funcHumanize,
})
return c.tpl
}
// OriginalReq returns the original, unmodified, un-rewritten request as
// it originally came in over the wire.
func (c TemplateContext) OriginalReq() http.Request {
or, _ := c.Req.Context().Value(caddyhttp.OriginalRequestCtxKey).(http.Request)
return or
}
// funcInclude returns the contents of filename relative to the site root and renders it in place.
// Note that included files are NOT escaped, so you should only include
// trusted files. If it is not trusted, be sure to use escaping functions
// in your template.
func (c TemplateContext) funcInclude(filename string, args ...any) (string, error) {
bodyBuf := bufPool.Get().(*bytes.Buffer)
bodyBuf.Reset()
defer bufPool.Put(bodyBuf)
err := c.readFileToBuffer(filename, bodyBuf)
if err != nil {
return "", err
}
c.Args = args
err = c.executeTemplateInBuffer(filename, bodyBuf)
if err != nil {
return "", err
}
return bodyBuf.String(), nil
}
// funcReadFile returns the contents of a filename relative to the site root.
// Note that included files are NOT escaped, so you should only include
// trusted files. If it is not trusted, be sure to use escaping functions
// in your template.
func (c TemplateContext) funcReadFile(filename string) (string, error) {
bodyBuf := bufPool.Get().(*bytes.Buffer)
bodyBuf.Reset()
defer bufPool.Put(bodyBuf)
err := c.readFileToBuffer(filename, bodyBuf)
if err != nil {
return "", err
}
return bodyBuf.String(), nil
}
// readFileToBuffer reads a file into a buffer
func (c TemplateContext) readFileToBuffer(filename string, bodyBuf *bytes.Buffer) error {
if c.Root == nil {
return fmt.Errorf("root file system not specified")
}
file, err := c.Root.Open(filename)
if err != nil {
return err
}
defer file.Close()
_, err = io.Copy(bodyBuf, file)
if err != nil {
return err
}
return nil
}
// funcHTTPInclude returns the body of a virtual (lightweight) request
// to the given URI on the same server. Note that included bodies
// are NOT escaped, so you should only include trusted resources.
// If it is not trusted, be sure to use escaping functions yourself.
func (c TemplateContext) funcHTTPInclude(uri string) (string, error) {
// prevent virtual request loops by counting how many levels
// deep we are; and if we get too deep, return an error
recursionCount := 1
if numStr := c.Req.Header.Get(recursionPreventionHeader); numStr != "" {
num, err := strconv.Atoi(numStr)
if err != nil {
return "", fmt.Errorf("parsing %s: %v", recursionPreventionHeader, err)
}
if num >= 3 {
return "", fmt.Errorf("virtual request cycle")
}
recursionCount = num + 1
}
buf := bufPool.Get().(*bytes.Buffer)
buf.Reset()
defer bufPool.Put(buf)
virtReq, err := http.NewRequest("GET", uri, nil)
if err != nil {
return "", err
}
virtReq.Host = c.Req.Host
virtReq.Header = c.Req.Header.Clone()
virtReq.Header.Set("Accept-Encoding", "identity") // https://github.com/caddyserver/caddy/issues/4352
virtReq.Trailer = c.Req.Trailer.Clone()
virtReq.Header.Set(recursionPreventionHeader, strconv.Itoa(recursionCount))
vrw := &virtualResponseWriter{body: buf, header: make(http.Header)}
server := c.Req.Context().Value(caddyhttp.ServerCtxKey).(http.Handler)
server.ServeHTTP(vrw, virtReq)
if vrw.status >= 400 {
return "", fmt.Errorf("http %d", vrw.status)
}
err = c.executeTemplateInBuffer(uri, buf)
if err != nil {
return "", err
}
return buf.String(), nil
}
// funcImport parses the filename into the current template stack. The imported
// file will be rendered within the current template by calling {{ block }} or
// {{ template }} from the standard template library. If the imported file has
// no {{ define }} blocks, the name of the import will be the path
func (c *TemplateContext) funcImport(filename string) (string, error) {
bodyBuf := bufPool.Get().(*bytes.Buffer)
bodyBuf.Reset()
defer bufPool.Put(bodyBuf)
err := c.readFileToBuffer(filename, bodyBuf)
if err != nil {
return "", err
}
_, err = c.tpl.Parse(bodyBuf.String())
if err != nil {
return "", err
}
return "", nil
}
func (c *TemplateContext) executeTemplateInBuffer(tplName string, buf *bytes.Buffer) error {
c.NewTemplate(tplName)
_, err := c.tpl.Parse(buf.String())
if err != nil {
return err
}
buf.Reset() // reuse buffer for output
return c.tpl.Execute(buf, c)
}
func (c TemplateContext) funcPlaceholder(name string) string {
repl := c.Req.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
value, _ := repl.GetString(name)
return value
}
func (TemplateContext) funcEnv(varName string) string {
return os.Getenv(varName)
}
// Cookie gets the value of a cookie with name name.
func (c TemplateContext) Cookie(name string) string {
cookies := c.Req.Cookies()
for _, cookie := range cookies {
if cookie.Name == name {
return cookie.Value
}
}
return ""
}
// RemoteIP gets the IP address of the client making the request.
func (c TemplateContext) RemoteIP() string {
ip, _, err := net.SplitHostPort(c.Req.RemoteAddr)
if err != nil {
return c.Req.RemoteAddr
}
return ip
}
// Host returns the hostname portion of the Host header
// from the HTTP request.
func (c TemplateContext) Host() (string, error) {
host, _, err := net.SplitHostPort(c.Req.Host)
if err != nil {
if !strings.Contains(c.Req.Host, ":") {
// common with sites served on the default port 80
return c.Req.Host, nil
}
return "", err
}
return host, nil
}
// funcStripHTML returns s without HTML tags. It is fairly naive
// but works with most valid HTML inputs.
func (TemplateContext) funcStripHTML(s string) string {
var buf bytes.Buffer
var inTag, inQuotes bool
var tagStart int
for i, ch := range s {
if inTag {
if ch == '>' && !inQuotes {
inTag = false
} else if ch == '<' && !inQuotes {
// false start
buf.WriteString(s[tagStart:i])
tagStart = i
} else if ch == '"' {
inQuotes = !inQuotes
}
continue
}
if ch == '<' {
inTag = true
tagStart = i
continue
}
buf.WriteRune(ch)
}
if inTag {
// false start
buf.WriteString(s[tagStart:])
}
return buf.String()
}
// funcMarkdown renders the markdown body as HTML. The resulting
// HTML is NOT escaped so that it can be rendered as HTML.
func (TemplateContext) funcMarkdown(input any) (string, error) {
inputStr := caddy.ToString(input)
md := goldmark.New(
goldmark.WithExtensions(
extension.GFM,
extension.Footnote,
highlighting.NewHighlighting(
highlighting.WithFormatOptions(
chromahtml.WithClasses(true),
),
),
),
goldmark.WithParserOptions(
parser.WithAutoHeadingID(),
),
goldmark.WithRendererOptions(
gmhtml.WithUnsafe(), // TODO: this is not awesome, maybe should be configurable?
),
)
buf := bufPool.Get().(*bytes.Buffer)
buf.Reset()
defer bufPool.Put(buf)
err := md.Convert([]byte(inputStr), buf)
if err != nil {
return "", err
}
return buf.String(), nil
}
// splitFrontMatter parses front matter out from the beginning of input,
// and returns the separated key-value pairs and the body/content. input
// must be a "stringy" value.
func (TemplateContext) funcSplitFrontMatter(input any) (parsedMarkdownDoc, error) {
meta, body, err := extractFrontMatter(caddy.ToString(input))
if err != nil {
return parsedMarkdownDoc{}, err
}
return parsedMarkdownDoc{Meta: meta, Body: body}, nil
}
// funcListFiles reads and returns a slice of names from the given
// directory relative to the root of c.
func (c TemplateContext) funcListFiles(name string) ([]string, error) {
if c.Root == nil {
return nil, fmt.Errorf("root file system not specified")
}
dir, err := c.Root.Open(path.Clean(name))
if err != nil {
return nil, err
}
defer dir.Close()
stat, err := dir.Stat()
if err != nil {
return nil, err
}
if !stat.IsDir() {
return nil, fmt.Errorf("%v is not a directory", name)
}
dirInfo, err := dir.Readdir(0)
if err != nil {
return nil, err
}
names := make([]string, len(dirInfo))
for i, fileInfo := range dirInfo {
names[i] = fileInfo.Name()
}
return names, nil
}
// funcFileExists returns true if filename can be opened successfully.
func (c TemplateContext) funcFileExists(filename string) (bool, error) {
if c.Root == nil {
return false, fmt.Errorf("root file system not specified")
}
file, err := c.Root.Open(filename)
if err == nil {
file.Close()
return true, nil
}
return false, nil
}
// funcFileStat returns Stat of a filename
func (c TemplateContext) funcFileStat(filename string) (fs.FileInfo, error) {
if c.Root == nil {
return nil, fmt.Errorf("root file system not specified")
}
file, err := c.Root.Open(path.Clean(filename))
if err != nil {
return nil, err
}
defer file.Close()
return file.Stat()
}
// funcHTTPError returns a structured HTTP handler error. EXPERIMENTAL; SUBJECT TO CHANGE.
// Example usage: `{{if not (fileExists $includeFile)}}{{httpError 404}}{{end}}`
func (c TemplateContext) funcHTTPError(statusCode int) (bool, error) {
return false, caddyhttp.Error(statusCode, nil)
}
// funcHumanize transforms size and time inputs to a human readable format.
//
// Size inputs are expected to be integers, and are formatted as a
// byte size, such as "83 MB".
//
// Time inputs are parsed using the given layout (default layout is RFC1123Z)
// and are formatted as a relative time, such as "2 weeks ago".
// See https://pkg.go.dev/time#pkg-constants for time layout docs.
func (c TemplateContext) funcHumanize(formatType, data string) (string, error) {
// The format type can optionally be followed
// by a colon to provide arguments for the format
parts := strings.Split(formatType, ":")
switch parts[0] {
case "size":
dataint, dataerr := strconv.ParseUint(data, 10, 64)
if dataerr != nil {
return "", fmt.Errorf("humanize: size cannot be parsed: %s", dataerr.Error())
}
return humanize.Bytes(dataint), nil
case "time":
timelayout := time.RFC1123Z
if len(parts) > 1 {
timelayout = parts[1]
}
dataint, dataerr := time.Parse(timelayout, data)
if dataerr != nil {
return "", fmt.Errorf("humanize: time cannot be parsed: %s", dataerr.Error())
}
return humanize.Time(dataint), nil
}
return "", fmt.Errorf("no know function was given")
}
// WrappedHeader wraps niladic functions so that they
// can be used in templates. (Template functions must
// return a value.)
type WrappedHeader struct{ http.Header }
// Add adds a header field value, appending val to
// existing values for that field. It returns an
// empty string.
func (h WrappedHeader) Add(field, val string) string {
h.Header.Add(field, val)
return ""
}
// Set sets a header field value, overwriting any
// other values for that field. It returns an
// empty string.
func (h WrappedHeader) Set(field, val string) string {
h.Header.Set(field, val)
return ""
}
// Del deletes a header field. It returns an empty string.
func (h WrappedHeader) Del(field string) string {
h.Header.Del(field)
return ""
}
var bufPool = sync.Pool{
New: func() any {
return new(bytes.Buffer)
},
}
// at time of writing, sprig.FuncMap() makes a copy, thus
// involves iterating the whole map, so do it just once
var sprigFuncMap = sprig.TxtFuncMap()
const recursionPreventionHeader = "Caddy-Templates-Include"