summaryrefslogtreecommitdiff
path: root/vendor/github.com/projectatomic/buildah/secrets.go
blob: 087bf6ba57152b09068db264ce4fc92df704001e (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
package buildah

import (
	"bufio"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"

	rspec "github.com/opencontainers/runtime-spec/specs-go"
	"github.com/opencontainers/selinux/go-selinux/label"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

var (
	// DefaultMountsFile holds the default mount paths in the form
	// "host_path:container_path"
	DefaultMountsFile = "/usr/share/containers/mounts.conf"
	// OverrideMountsFile holds the default mount paths in the form
	// "host_path:container_path" overriden by the user
	OverrideMountsFile = "/etc/containers/mounts.conf"
)

// secretData stores the name of the file and the content read from it
type secretData struct {
	name string
	data []byte
}

// saveTo saves secret data to given directory
func (s secretData) saveTo(dir string) error {
	path := filepath.Join(dir, s.name)
	if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil && !os.IsExist(err) {
		return err
	}
	return ioutil.WriteFile(path, s.data, 0700)
}

func readAll(root, prefix string) ([]secretData, error) {
	path := filepath.Join(root, prefix)

	data := []secretData{}

	files, err := ioutil.ReadDir(path)
	if err != nil {
		if os.IsNotExist(err) {
			return data, nil
		}

		return nil, err
	}

	for _, f := range files {
		fileData, err := readFile(root, filepath.Join(prefix, f.Name()))
		if err != nil {
			// If the file did not exist, might be a dangling symlink
			// Ignore the error
			if os.IsNotExist(err) {
				continue
			}
			return nil, err
		}
		data = append(data, fileData...)
	}

	return data, nil
}

func readFile(root, name string) ([]secretData, error) {
	path := filepath.Join(root, name)

	s, err := os.Stat(path)
	if err != nil {
		return nil, err
	}

	if s.IsDir() {
		dirData, err := readAll(root, name)
		if err != nil {
			return nil, err
		}
		return dirData, nil
	}
	bytes, err := ioutil.ReadFile(path)
	if err != nil {
		return nil, err
	}
	return []secretData{{name: name, data: bytes}}, nil
}

func getHostSecretData(hostDir string) ([]secretData, error) {
	var allSecrets []secretData
	hostSecrets, err := readAll(hostDir, "")
	if err != nil {
		return nil, errors.Wrapf(err, "failed to read secrets from %q", hostDir)
	}
	return append(allSecrets, hostSecrets...), nil
}

func getMounts(filePath string) []string {
	file, err := os.Open(filePath)
	if err != nil {
		logrus.Warnf("file %q not found, skipping...", filePath)
		return nil
	}
	defer file.Close()
	scanner := bufio.NewScanner(file)
	if err = scanner.Err(); err != nil {
		logrus.Warnf("error reading file %q, skipping...", filePath)
		return nil
	}
	var mounts []string
	for scanner.Scan() {
		mounts = append(mounts, scanner.Text())
	}
	return mounts
}

// getHostAndCtrDir separates the host:container paths
func getMountsMap(path string) (string, string, error) {
	arr := strings.SplitN(path, ":", 2)
	if len(arr) == 2 {
		return arr[0], arr[1], nil
	}
	return "", "", errors.Errorf("unable to get host and container dir")
}

// secretMount copies the contents of host directory to container directory
// and returns a list of mounts
func secretMounts(filePath, mountLabel, containerWorkingDir string) ([]rspec.Mount, error) {
	var mounts []rspec.Mount
	defaultMountsPaths := getMounts(filePath)
	for _, path := range defaultMountsPaths {
		hostDir, ctrDir, err := getMountsMap(path)
		if err != nil {
			return nil, err
		}
		// skip if the hostDir path doesn't exist
		if _, err = os.Stat(hostDir); os.IsNotExist(err) {
			logrus.Warnf("%q doesn't exist, skipping", hostDir)
			continue
		}

		ctrDirOnHost := filepath.Join(containerWorkingDir, ctrDir)
		if err = os.RemoveAll(ctrDirOnHost); err != nil {
			return nil, fmt.Errorf("remove container directory failed: %v", err)
		}

		if err = os.MkdirAll(ctrDirOnHost, 0755); err != nil {
			return nil, fmt.Errorf("making container directory failed: %v", err)
		}

		hostDir, err = resolveSymbolicLink(hostDir)
		if err != nil {
			return nil, err
		}

		data, err := getHostSecretData(hostDir)
		if err != nil {
			return nil, errors.Wrapf(err, "getting host secret data failed")
		}
		for _, s := range data {
			if err := s.saveTo(ctrDirOnHost); err != nil {
				return nil, errors.Wrapf(err, "error saving data to container filesystem on host %q", ctrDirOnHost)
			}
		}

		err = label.Relabel(ctrDirOnHost, mountLabel, false)
		if err != nil {
			return nil, errors.Wrap(err, "error applying correct labels")
		}

		m := rspec.Mount{
			Source:      ctrDirOnHost,
			Destination: ctrDir,
			Type:        "bind",
			Options:     []string{"bind"},
		}

		mounts = append(mounts, m)
	}
	return mounts, nil
}

// resolveSymbolicLink resolves a possbile symlink path. If the path is a symlink, returns resolved
// path; if not, returns the original path.
func resolveSymbolicLink(path string) (string, error) {
	info, err := os.Lstat(path)
	if err != nil {
		return "", err
	}
	if info.Mode()&os.ModeSymlink != os.ModeSymlink {
		return path, nil
	}
	return filepath.EvalSymlinks(path)
}