forked from docker/machine
/
utils.go
133 lines (113 loc) · 2.57 KB
/
utils.go
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package mcnutils
import (
"crypto/rand"
"encoding/hex"
"fmt"
"io"
"os"
"runtime"
"strconv"
"time"
)
type MultiError struct {
Errs []error
}
func (e MultiError) Error() string {
aggregate := ""
for _, err := range e.Errs {
aggregate += err.Error() + "\n"
}
return aggregate
}
// GetHomeDir returns the home directory
// TODO: Having this here just strikes me as dangerous, but some of the drivers
// depend on it ;_;
func GetHomeDir() string {
if runtime.GOOS == "windows" {
return os.Getenv("USERPROFILE")
}
return os.Getenv("HOME")
}
func GetUsername() string {
u := "unknown"
osUser := ""
switch runtime.GOOS {
case "darwin", "linux":
osUser = os.Getenv("USER")
case "windows":
osUser = os.Getenv("USERNAME")
}
if osUser != "" {
u = osUser
}
return u
}
func CopyFile(src, dst string) error {
in, err := os.Open(src)
if err != nil {
return err
}
defer in.Close()
out, err := os.Create(dst)
if err != nil {
return err
}
defer out.Close()
if _, err = io.Copy(out, in); err != nil {
return err
}
fi, err := os.Stat(src)
if err != nil {
return err
}
return os.Chmod(dst, fi.Mode())
}
func WaitForSpecificOrError(f func() (bool, error), maxAttempts int, waitInterval time.Duration) error {
for i := 0; i < maxAttempts; i++ {
stop, err := f()
if err != nil {
return err
}
if stop {
return nil
}
time.Sleep(waitInterval)
}
return fmt.Errorf("Maximum number of retries (%d) exceeded", maxAttempts)
}
func WaitForSpecific(f func() bool, maxAttempts int, waitInterval time.Duration) error {
return WaitForSpecificOrError(func() (bool, error) {
return f(), nil
}, maxAttempts, waitInterval)
}
func WaitFor(f func() bool) error {
return WaitForSpecific(f, 60, 3*time.Second)
}
// TruncateID returns a shorten id
// Following two functions are from github.com/docker/docker/utils module. It
// was way overkill to include the whole module, so we just have these bits
// that we're using here.
func TruncateID(id string) string {
shortLen := 12
if len(id) < shortLen {
shortLen = len(id)
}
return id[:shortLen]
}
// GenerateRandomID returns an unique id
func GenerateRandomID() string {
for {
id := make([]byte, 32)
if _, err := io.ReadFull(rand.Reader, id); err != nil {
panic(err) // This shouldn't happen
}
value := hex.EncodeToString(id)
// if we try to parse the truncated for as an int and we don't have
// an error then the value is all numeric and causes issues when
// used as a hostname. ref #3869
if _, err := strconv.ParseInt(TruncateID(value), 10, 64); err == nil {
continue
}
return value
}
}