Files
ReleaseKit/internal/tempdir/tempdir.go

85 lines
2.2 KiB
Go

// Package tempdir allocates disposable storage outside a source worktree.
package tempdir
import (
"fmt"
"os"
"path/filepath"
"strings"
)
// Outside uses system temporary storage and falls back to the repository's
// parent when TMPDIR resolves inside the worktree. Cleanup belongs to the caller.
func Outside(repositoryDir, pattern string) (string, error) {
repository, err := filepath.Abs(repositoryDir)
if err != nil {
return "", err
}
repository, err = filepath.EvalSymlinks(repository)
if err != nil {
return "", err
}
directory, err := os.MkdirTemp("", pattern)
if err != nil {
return "", err
}
created := directory
directory, err = filepath.Abs(created)
if err != nil {
os.RemoveAll(created)
return "", err
}
directory, err = filepath.EvalSymlinks(directory)
if err != nil {
os.RemoveAll(directory)
return "", err
}
outside, err := isOutside(repository, directory)
if err != nil {
os.RemoveAll(directory)
return "", err
}
if outside {
return directory, nil
}
if err := os.RemoveAll(directory); err != nil {
return "", fmt.Errorf("remove temporary storage inside repository %q: %w", repository, err)
}
directory, err = os.MkdirTemp(filepath.Dir(repository), pattern)
if err != nil {
return "", fmt.Errorf("create temporary storage outside repository %q: %w", repository, err)
}
created = directory
directory, err = filepath.Abs(created)
if err != nil {
os.RemoveAll(created)
return "", err
}
directory, err = filepath.EvalSymlinks(directory)
if err != nil {
os.RemoveAll(directory)
return "", err
}
outside, err = isOutside(repository, directory)
if err != nil {
os.RemoveAll(directory)
return "", err
}
if !outside {
os.RemoveAll(directory)
return "", fmt.Errorf("temporary storage %q is inside repository %q", directory, repository)
}
return directory, nil
}
func isOutside(repository, directory string) (bool, error) {
if !strings.EqualFold(filepath.VolumeName(repository), filepath.VolumeName(directory)) {
return true, nil
}
relative, err := filepath.Rel(repository, directory)
if err != nil {
return false, err
}
return relative == ".." || strings.HasPrefix(relative, ".."+string(filepath.Separator)), nil
}