summaryrefslogtreecommitdiff
path: root/vendor/github.com/openshift/imagebuilder/builder.go
blob: 16682af7d7f4d87d2bad2a187de5598236f2edf5 (plain)
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
package imagebuilder

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"

	docker "github.com/fsouza/go-dockerclient"

	"github.com/docker/docker/builder/dockerfile/command"
	"github.com/docker/docker/builder/dockerfile/parser"
)

// Copy defines a copy operation required on the container.
type Copy struct {
	// If true, this is a copy from the file system to the container. If false,
	// the copy is from the context.
	FromFS bool
	// If set, this is a copy from the named stage or image to the container.
	From     string
	Src      []string
	Dest     string
	Download bool
	// If set, the owner:group for the destination.  This value is passed
	// to the executor for handling.
	Chown string
}

// Run defines a run operation required in the container.
type Run struct {
	Shell bool
	Args  []string
}

type Executor interface {
	Preserve(path string) error
	EnsureContainerPath(path string) error
	Copy(excludes []string, copies ...Copy) error
	Run(run Run, config docker.Config) error
	UnrecognizedInstruction(step *Step) error
}

type logExecutor struct{}

func (logExecutor) Preserve(path string) error {
	log.Printf("PRESERVE %s", path)
	return nil
}

func (logExecutor) EnsureContainerPath(path string) error {
	log.Printf("ENSURE %s", path)
	return nil
}

func (logExecutor) Copy(excludes []string, copies ...Copy) error {
	for _, c := range copies {
		log.Printf("COPY %v -> %s (from:%s download:%t), chown: %s", c.Src, c.Dest, c.From, c.Download, c.Chown)
	}
	return nil
}

func (logExecutor) Run(run Run, config docker.Config) error {
	log.Printf("RUN %v %t (%v)", run.Args, run.Shell, config.Env)
	return nil
}

func (logExecutor) UnrecognizedInstruction(step *Step) error {
	log.Printf("Unknown instruction: %s", strings.ToUpper(step.Command))
	return nil
}

type noopExecutor struct{}

func (noopExecutor) Preserve(path string) error {
	return nil
}

func (noopExecutor) EnsureContainerPath(path string) error {
	return nil
}

func (noopExecutor) Copy(excludes []string, copies ...Copy) error {
	return nil
}

func (noopExecutor) Run(run Run, config docker.Config) error {
	return nil
}

func (noopExecutor) UnrecognizedInstruction(step *Step) error {
	return nil
}

type VolumeSet []string

func (s *VolumeSet) Add(path string) bool {
	if path == "/" {
		set := len(*s) != 1 || (*s)[0] != ""
		*s = []string{""}
		return set
	}
	path = strings.TrimSuffix(path, "/")
	var adjusted []string
	for _, p := range *s {
		if p == path || strings.HasPrefix(path, p+"/") {
			return false
		}
		if strings.HasPrefix(p, path+"/") {
			continue
		}
		adjusted = append(adjusted, p)
	}
	adjusted = append(adjusted, path)
	*s = adjusted
	return true
}

func (s VolumeSet) Has(path string) bool {
	if path == "/" {
		return len(s) == 1 && s[0] == ""
	}
	path = strings.TrimSuffix(path, "/")
	for _, p := range s {
		if p == path {
			return true
		}
	}
	return false
}

func (s VolumeSet) Covers(path string) bool {
	if path == "/" {
		return len(s) == 1 && s[0] == ""
	}
	path = strings.TrimSuffix(path, "/")
	for _, p := range s {
		if p == path || strings.HasPrefix(path, p+"/") {
			return true
		}
	}
	return false
}

var (
	LogExecutor  = logExecutor{}
	NoopExecutor = noopExecutor{}
)

type Stages []Stage

func (stages Stages) ByName(name string) (Stage, bool) {
	for _, stage := range stages {
		if stage.Name == name {
			return stage, true
		}
	}
	return Stage{}, false
}

// Get just the target stage.
func (stages Stages) ByTarget(target string) (Stages, bool) {
	if len(target) == 0 {
		return stages, true
	}
	for i, stage := range stages {
		if stage.Name == target {
			return stages[i : i+1], true
		}
	}
	return nil, false
}

// Get all the stages up to and including the target.
func (stages Stages) ThroughTarget(target string) (Stages, bool) {
	if len(target) == 0 {
		return stages, true
	}
	for i, stage := range stages {
		if stage.Name == target {
			return stages[0 : i+1], true
		}
	}
	return nil, false
}

type Stage struct {
	Position int
	Name     string
	Builder  *Builder
	Node     *parser.Node
}

func NewStages(node *parser.Node, b *Builder) (Stages, error) {
	var stages Stages
	if err := b.extractHeadingArgsFromNode(node); err != nil {
		return stages, err
	}
	for i, root := range SplitBy(node, command.From) {
		name, _ := extractNameFromNode(root.Children[0])
		if len(name) == 0 {
			name = strconv.Itoa(i)
		}
		stages = append(stages, Stage{
			Position: i,
			Name:     name,
			Builder: &Builder{
				Args:        b.Args,
				AllowedArgs: b.AllowedArgs,
			},
			Node: root,
		})
	}
	return stages, nil
}

func (b *Builder) extractHeadingArgsFromNode(node *parser.Node) error {
	var args []*parser.Node
	var children []*parser.Node
	extract := true
	for _, child := range node.Children {
		if extract && child.Value == command.Arg {
			args = append(args, child)
		} else {
			if child.Value == command.From {
				extract = false
			}
			children = append(children, child)
		}
	}

	for _, c := range args {
		step := b.Step()
		if err := step.Resolve(c); err != nil {
			return err
		}
		if err := b.Run(step, NoopExecutor, false); err != nil {
			return err
		}
	}

	node.Children = children
	return nil
}

func extractNameFromNode(node *parser.Node) (string, bool) {
	if node.Value != command.From {
		return "", false
	}
	n := node.Next
	if n == nil || n.Next == nil {
		return "", false
	}
	n = n.Next
	if !strings.EqualFold(n.Value, "as") || n.Next == nil || len(n.Next.Value) == 0 {
		return "", false
	}
	return n.Next.Value, true
}

type Builder struct {
	RunConfig docker.Config

	Env    []string
	Args   map[string]string
	CmdSet bool
	Author string

	AllowedArgs map[string]bool
	Volumes     VolumeSet
	Excludes    []string

	PendingVolumes VolumeSet
	PendingRuns    []Run
	PendingCopies  []Copy

	Warnings []string
}

func NewBuilder(args map[string]string) *Builder {
	allowed := make(map[string]bool)
	for k, v := range builtinAllowedBuildArgs {
		allowed[k] = v
	}
	return &Builder{
		Args:        args,
		AllowedArgs: allowed,
	}
}

func ParseFile(path string) (*parser.Node, error) {
	f, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	return ParseDockerfile(f)
}

// Step creates a new step from the current state.
func (b *Builder) Step() *Step {
	dst := make([]string, len(b.Env)+len(b.RunConfig.Env))
	copy(dst, b.Env)
	dst = append(dst, b.RunConfig.Env...)
	dst = append(dst, b.Arguments()...)
	return &Step{Env: dst}
}

// Run executes a step, transforming the current builder and
// invoking any Copy or Run operations. noRunsRemaining is an
// optimization hint that allows the builder to avoid performing
// unnecessary work.
func (b *Builder) Run(step *Step, exec Executor, noRunsRemaining bool) error {
	fn, ok := evaluateTable[step.Command]
	if !ok {
		return exec.UnrecognizedInstruction(step)
	}
	if err := fn(b, step.Args, step.Attrs, step.Flags, step.Original); err != nil {
		return err
	}

	copies := b.PendingCopies
	b.PendingCopies = nil
	runs := b.PendingRuns
	b.PendingRuns = nil

	// Once a VOLUME is defined, future ADD/COPY instructions are
	// all that may mutate that path. Instruct the executor to preserve
	// the path. The executor must handle invalidating preserved info.
	for _, path := range b.PendingVolumes {
		if b.Volumes.Add(path) && !noRunsRemaining {
			if err := exec.Preserve(path); err != nil {
				return err
			}
		}
	}

	if err := exec.Copy(b.Excludes, copies...); err != nil {
		return err
	}

	if len(b.RunConfig.WorkingDir) > 0 {
		if err := exec.EnsureContainerPath(b.RunConfig.WorkingDir); err != nil {
			return err
		}
	}

	for _, run := range runs {
		config := b.Config()
		config.Env = step.Env
		if err := exec.Run(run, *config); err != nil {
			return err
		}
	}

	return nil
}

// RequiresStart returns true if a running container environment is necessary
// to invoke the provided commands
func (b *Builder) RequiresStart(node *parser.Node) bool {
	for _, child := range node.Children {
		if child.Value == command.Run {
			return true
		}
	}
	return false
}

// Config returns a snapshot of the current RunConfig intended for
// use with a container commit.
func (b *Builder) Config() *docker.Config {
	config := b.RunConfig
	if config.OnBuild == nil {
		config.OnBuild = []string{}
	}
	if config.Entrypoint == nil {
		config.Entrypoint = []string{}
	}
	config.Image = ""
	return &config
}

// Arguments returns the currently active arguments.
func (b *Builder) Arguments() []string {
	var envs []string
	for key, val := range b.Args {
		if _, ok := b.AllowedArgs[key]; ok {
			envs = append(envs, fmt.Sprintf("%s=%s", key, val))
		}
	}
	return envs
}

// ErrNoFROM is returned if the Dockerfile did not contain a FROM
// statement.
var ErrNoFROM = fmt.Errorf("no FROM statement found")

// From returns the image this dockerfile depends on, or an error
// if no FROM is found or if multiple FROM are specified. If a
// single from is found the passed node is updated with only
// the remaining statements.  The builder's RunConfig.Image field
// is set to the first From found, or left unchanged if already
// set.
func (b *Builder) From(node *parser.Node) (string, error) {
	if err := b.extractHeadingArgsFromNode(node); err != nil {
		return "", err
	}
	children := SplitChildren(node, command.From)
	switch {
	case len(children) == 0:
		return "", ErrNoFROM
	case len(children) > 1:
		return "", fmt.Errorf("multiple FROM statements are not supported")
	default:
		step := b.Step()
		if err := step.Resolve(children[0]); err != nil {
			return "", err
		}
		if err := b.Run(step, NoopExecutor, false); err != nil {
			return "", err
		}
		return b.RunConfig.Image, nil
	}
}

// FromImage updates the builder to use the provided image (resetting RunConfig
// and recording the image environment), and updates the node with any ONBUILD
// statements extracted from the parent image.
func (b *Builder) FromImage(image *docker.Image, node *parser.Node) error {
	SplitChildren(node, command.From)

	b.RunConfig = *image.Config
	b.Env = b.RunConfig.Env
	b.RunConfig.Env = nil

	// Check to see if we have a default PATH, note that windows won't
	// have one as its set by HCS
	if runtime.GOOS != "windows" && !hasEnvName(b.Env, "PATH") {
		b.RunConfig.Env = append(b.RunConfig.Env, "PATH="+defaultPathEnv)
	}

	// Join the image onbuild statements into node
	if image.Config == nil || len(image.Config.OnBuild) == 0 {
		return nil
	}
	extra, err := ParseDockerfile(bytes.NewBufferString(strings.Join(image.Config.OnBuild, "\n")))
	if err != nil {
		return err
	}
	for _, child := range extra.Children {
		switch strings.ToUpper(child.Value) {
		case "ONBUILD":
			return fmt.Errorf("Chaining ONBUILD via `ONBUILD ONBUILD` isn't allowed")
		case "MAINTAINER", "FROM":
			return fmt.Errorf("%s isn't allowed as an ONBUILD trigger", child.Value)
		}
	}
	node.Children = append(extra.Children, node.Children...)
	// Since we've processed the OnBuild statements, clear them from the runconfig state.
	b.RunConfig.OnBuild = nil
	return nil
}

// SplitChildren removes any children with the provided value from node
// and returns them as an array. node.Children is updated.
func SplitChildren(node *parser.Node, value string) []*parser.Node {
	var split []*parser.Node
	var children []*parser.Node
	for _, child := range node.Children {
		if child.Value == value {
			split = append(split, child)
		} else {
			children = append(children, child)
		}
	}
	node.Children = children
	return split
}

func SplitBy(node *parser.Node, value string) []*parser.Node {
	var split []*parser.Node
	var current *parser.Node
	for _, child := range node.Children {
		if current == nil || child.Value == value {
			copied := *node
			current = &copied
			current.Children = nil
			current.Next = nil
			split = append(split, current)
		}
		current.Children = append(current.Children, child)
	}
	return split
}

// StepFunc is invoked with the result of a resolved step.
type StepFunc func(*Builder, []string, map[string]bool, []string, string) error

var evaluateTable = map[string]StepFunc{
	command.Env:         env,
	command.Label:       label,
	command.Maintainer:  maintainer,
	command.Add:         add,
	command.Copy:        dispatchCopy, // copy() is a go builtin
	command.From:        from,
	command.Onbuild:     onbuild,
	command.Workdir:     workdir,
	command.Run:         run,
	command.Cmd:         cmd,
	command.Entrypoint:  entrypoint,
	command.Expose:      expose,
	command.Volume:      volume,
	command.User:        user,
	command.StopSignal:  stopSignal,
	command.Arg:         arg,
	command.Healthcheck: healthcheck,
	command.Shell:       shell,
}

// builtinAllowedBuildArgs is list of built-in allowed build args
var builtinAllowedBuildArgs = map[string]bool{
	"HTTP_PROXY":  true,
	"http_proxy":  true,
	"HTTPS_PROXY": true,
	"https_proxy": true,
	"FTP_PROXY":   true,
	"ftp_proxy":   true,
	"NO_PROXY":    true,
	"no_proxy":    true,
}

// ParseDockerIgnore returns a list of the excludes in the .dockerignore file.
// extracted from fsouza/go-dockerclient.
func ParseDockerignore(root string) ([]string, error) {
	var excludes []string
	ignore, err := ioutil.ReadFile(filepath.Join(root, ".dockerignore"))
	if err != nil && !os.IsNotExist(err) {
		return excludes, fmt.Errorf("error reading .dockerignore: '%s'", err)
	}
	return strings.Split(string(ignore), "\n"), nil
}

// ExportEnv creates an export statement for a shell that contains all of the
// provided environment.
func ExportEnv(env []string) string {
	if len(env) == 0 {
		return ""
	}
	out := "export"
	for _, e := range env {
		if len(e) == 0 {
			continue
		}
		out += " " + BashQuote(e)
	}
	return out + "; "
}

// BashQuote escapes the provided string and surrounds it with double quotes.
// TODO: verify that these are all we have to escape.
func BashQuote(env string) string {
	out := []rune{'"'}
	for _, r := range env {
		switch r {
		case '$', '\\', '"':
			out = append(out, '\\', r)
		default:
			out = append(out, r)
		}
	}
	out = append(out, '"')
	return string(out)
}