-
Notifications
You must be signed in to change notification settings - Fork 9
/
readfiles.go
153 lines (122 loc) · 3.45 KB
/
readfiles.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
// Copyright 2022 Namespace Labs Inc; All rights reserved.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
package oci
import (
"archive/tar"
"context"
"io"
"io/fs"
"sort"
v1 "github.com/google/go-containerregistry/pkg/v1"
"namespacelabs.dev/foundation/internal/compute"
"namespacelabs.dev/foundation/internal/fnerrors"
"namespacelabs.dev/foundation/internal/fnfs/memfs"
"namespacelabs.dev/foundation/internal/fnfs/tarfs"
"namespacelabs.dev/foundation/std/tasks"
)
func ReadFiles(image NamedImage, paths ...string) compute.Computable[fs.FS] {
return &readFiles{image: image, paths: paths}
}
type readFiles struct {
image NamedImage
paths []string
compute.LocalScoped[fs.FS]
}
func (r *readFiles) Inputs() *compute.In {
return compute.Inputs().Strs("paths", r.paths).Computable("image", r.image.Image())
}
func (r *readFiles) Action() *tasks.ActionEvent {
return tasks.Action("oci.read-image-contents").Arg("image", r.image.Description()).Arg("paths", r.paths)
}
func (r *readFiles) Compute(ctx context.Context, deps compute.Resolved) (fs.FS, error) {
return ReadFilesFromImage(compute.MustGetDepValue(deps, r.image.Image(), "image"), r.paths...)
}
type leftMap map[string]struct{}
func (lm leftMap) Has(p string) bool {
_, ok := lm[p]
return ok
}
func ReadFilesFromImage(img v1.Image, paths ...string) (*memfs.FS, error) {
left := leftMap{}
for _, p := range paths {
left[p] = struct{}{}
}
digest, err := img.Digest()
if err != nil {
return nil, fnerrors.BadInputError("failed to obtain image digest: %v", err)
}
layers, err := img.Layers()
if err != nil {
return nil, fnerrors.BadInputError("%s: failed to get layer list", digest)
}
var inmem memfs.FS
for k := len(layers) - 1; k >= 0; k-- {
if len(left) == 0 {
break
}
readFiles, err := tarfs.ReadFilesInto(&inmem, layers[k].Uncompressed, left)
if err != nil {
return nil, fnerrors.BadInputError("%s: failed at layer %d: %w", digest, k, err)
}
for _, f := range readFiles {
delete(left, f)
}
}
if len(left) > 0 {
var pathsLeft []string
for p := range left {
pathsLeft = append(pathsLeft, p)
}
sort.Strings(pathsLeft)
if len(pathsLeft) == 1 {
return nil, fnerrors.BadInputError("%s: no such file %q", digest, pathsLeft[0])
}
return nil, fnerrors.BadInputError("%s: %d files missing, e.g. %q", digest, len(pathsLeft), pathsLeft[0])
}
return &inmem, nil
}
func ReadFileFromImage(ctx context.Context, img v1.Image, path string) ([]byte, error) {
vfs, err := ReadFilesFromImage(img, path)
if err != nil {
return nil, err
}
return fs.ReadFile(vfs, path)
}
func VisitFilesFromImage(img v1.Image, visitor func(layer, path string, typ byte, contents []byte) error) error {
layers, err := img.Layers()
if err != nil {
return err
}
for _, layer := range layers {
digest, err := layer.Digest()
if err != nil {
return err
}
r, err := layer.Uncompressed()
if err != nil {
return err
}
defer r.Close()
tr := tar.NewReader(r)
for {
h, err := tr.Next()
if err == io.EOF {
break
}
var contents []byte
if h.Typeflag == tar.TypeReg {
contents, err = io.ReadAll(tr)
if err != nil {
return err
}
} else if h.Typeflag == tar.TypeLink || h.Typeflag == tar.TypeSymlink {
contents = []byte(h.Linkname)
}
if err := visitor(digest.String(), h.Name, h.Typeflag, contents); err != nil {
return err
}
}
}
return nil
}