aboutsummaryrefslogtreecommitdiff
path: root/libpod/util.go
blob: b0c25074be70b64d1ea13f53f7b868dd5a0c473d (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
package libpod

import (
	"fmt"
	"os"
	"path/filepath"
	"sort"
	"strconv"
	"strings"
	"time"

	"github.com/containers/image/signature"
	"github.com/containers/image/types"
	"github.com/containers/libpod/libpod/define"
	"github.com/fsnotify/fsnotify"
	spec "github.com/opencontainers/runtime-spec/specs-go"
	"github.com/pkg/errors"
)

// Runtime API constants
const (
	// DefaultTransport is a prefix that we apply to an image name
	// to check docker hub first for the image
	DefaultTransport = "docker://"
)

// FuncTimer helps measure the execution time of a function
// For debug purposes, do not leave in code
// used like defer FuncTimer("foo")
func FuncTimer(funcName string) {
	elapsed := time.Since(time.Now())
	fmt.Printf("%s executed in %d ms\n", funcName, elapsed)
}

// CopyStringStringMap deep copies a map[string]string and returns the result
func CopyStringStringMap(m map[string]string) map[string]string {
	n := map[string]string{}
	for k, v := range m {
		n[k] = v
	}
	return n
}

// GetPolicyContext creates a signature policy context for the given signature policy path
func GetPolicyContext(path string) (*signature.PolicyContext, error) {
	policy, err := signature.DefaultPolicy(&types.SystemContext{SignaturePolicyPath: path})
	if err != nil {
		return nil, err
	}
	return signature.NewPolicyContext(policy)
}

// RemoveScientificNotationFromFloat returns a float without any
// scientific notation if the number has any.
// golang does not handle conversion of float64s that have scientific
// notation in them and otherwise stinks.  please replace this if you have
// a better implementation.
func RemoveScientificNotationFromFloat(x float64) (float64, error) {
	bigNum := strconv.FormatFloat(x, 'g', -1, 64)
	breakPoint := strings.IndexAny(bigNum, "Ee")
	if breakPoint > 0 {
		bigNum = bigNum[:breakPoint]
	}
	result, err := strconv.ParseFloat(bigNum, 64)
	if err != nil {
		return x, errors.Wrapf(err, "unable to remove scientific number from calculations")
	}
	return result, nil
}

// MountExists returns true if dest exists in the list of mounts
func MountExists(specMounts []spec.Mount, dest string) bool {
	for _, m := range specMounts {
		if m.Destination == dest {
			return true
		}
	}
	return false
}

// WaitForFile waits until a file has been created or the given timeout has occurred
func WaitForFile(path string, chWait chan error, timeout time.Duration) (bool, error) {
	var inotifyEvents chan fsnotify.Event
	watcher, err := fsnotify.NewWatcher()
	if err == nil {
		if err := watcher.Add(filepath.Dir(path)); err == nil {
			inotifyEvents = watcher.Events
		}
		defer watcher.Close()
	}

	timeoutChan := time.After(timeout)

	for {
		select {
		case e := <-chWait:
			return true, e
		case <-inotifyEvents:
			_, err := os.Stat(path)
			if err == nil {
				return false, nil
			}
			if !os.IsNotExist(err) {
				return false, errors.Wrapf(err, "checking file %s", path)
			}
		case <-time.After(25 * time.Millisecond):
			// Check periodically for the file existence.  It is needed
			// if the inotify watcher could not have been created.  It is
			// also useful when using inotify as if for any reasons we missed
			// a notification, we won't hang the process.
			_, err := os.Stat(path)
			if err == nil {
				return false, nil
			}
			if !os.IsNotExist(err) {
				return false, errors.Wrapf(err, "checking file %s", path)
			}
		case <-timeoutChan:
			return false, errors.Wrapf(define.ErrInternal, "timed out waiting for file %s", path)
		}
	}
}

type byDestination []spec.Mount

func (m byDestination) Len() int {
	return len(m)
}

func (m byDestination) Less(i, j int) bool {
	return m.parts(i) < m.parts(j)
}

func (m byDestination) Swap(i, j int) {
	m[i], m[j] = m[j], m[i]
}

func (m byDestination) parts(i int) int {
	return strings.Count(filepath.Clean(m[i].Destination), string(os.PathSeparator))
}

func sortMounts(m []spec.Mount) []spec.Mount {
	sort.Sort(byDestination(m))
	return m
}

func validPodNSOption(p *Pod, ctrPod string) error {
	if p == nil {
		return errors.Wrapf(define.ErrInvalidArg, "pod passed in was nil. Container may not be associated with a pod")
	}

	if ctrPod == "" {
		return errors.Wrapf(define.ErrInvalidArg, "container is not a member of any pod")
	}

	if ctrPod != p.ID() {
		return errors.Wrapf(define.ErrInvalidArg, "pod passed in is not the pod the container is associated with")
	}
	return nil
}

// JSONDeepCopy performs a deep copy by performing a JSON encode/decode of the
// given structures. From and To should be identically typed structs.
func JSONDeepCopy(from, to interface{}) error {
	tmp, err := json.Marshal(from)
	if err != nil {
		return err
	}
	return json.Unmarshal(tmp, to)
}