56 lines
1.4 KiB
Go
56 lines
1.4 KiB
Go
package utils
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import (
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"crypto/rand"
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"encoding/hex"
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"io"
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"io/ioutil"
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"path/filepath"
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"strconv"
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"syscall"
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)
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// GenerateRandomName returns a new name joined with a prefix. This size
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// specified is used to truncate the randomly generated value
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func GenerateRandomName(prefix string, size int) (string, error) {
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id := make([]byte, 32)
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if _, err := io.ReadFull(rand.Reader, id); err != nil {
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return "", err
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}
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return prefix + hex.EncodeToString(id)[:size], nil
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}
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// ResolveRootfs ensures that the current working directory is
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// not a symlink and returns the absolute path to the rootfs
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func ResolveRootfs(uncleanRootfs string) (string, error) {
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rootfs, err := filepath.Abs(uncleanRootfs)
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if err != nil {
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return "", err
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}
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return filepath.EvalSymlinks(rootfs)
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}
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func CloseExecFrom(minFd int) error {
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fdList, err := ioutil.ReadDir("/proc/self/fd")
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if err != nil {
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return err
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}
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for _, fi := range fdList {
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fd, err := strconv.Atoi(fi.Name())
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if err != nil {
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// ignore non-numeric file names
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continue
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}
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if fd < minFd {
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// ignore descriptors lower than our specified minimum
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continue
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}
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// intentionally ignore errors from syscall.CloseOnExec
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syscall.CloseOnExec(fd)
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// the cases where this might fail are basically file descriptors that have already been closed (including and especially the one that was created when ioutil.ReadDir did the "opendir" syscall)
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}
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return nil
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}
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