99 lines
2.1 KiB
Go
99 lines
2.1 KiB
Go
package system
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import (
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"errors"
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"fmt"
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"io/ioutil"
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"os"
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"os/exec"
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"path"
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"strconv"
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"github.com/coreos/coreos-cloudinit/config"
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)
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// File is a top-level structure which embeds its underlying configuration,
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// config.File, and provides the system-specific Permissions().
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type File struct {
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config.File
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}
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func (f *File) Permissions() (os.FileMode, error) {
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if f.RawFilePermissions == "" {
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return os.FileMode(0644), nil
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}
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// Parse string representation of file mode as octal
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perm, err := strconv.ParseInt(f.RawFilePermissions, 8, 32)
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if err != nil {
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return 0, errors.New("Unable to parse file permissions as octal integer")
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}
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return os.FileMode(perm), nil
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}
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func WriteFile(f *File, root string) (string, error) {
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if f.Encoding != "" {
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return "", fmt.Errorf("Unable to write file with encoding %s", f.Encoding)
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}
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fullpath := path.Join(root, f.Path)
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dir := path.Dir(fullpath)
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if err := EnsureDirectoryExists(dir); err != nil {
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return "", err
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}
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perm, err := f.Permissions()
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if err != nil {
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return "", err
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}
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var tmp *os.File
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// Create a temporary file in the same directory to ensure it's on the same filesystem
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if tmp, err = ioutil.TempFile(dir, "cloudinit-temp"); err != nil {
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return "", err
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}
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if err := ioutil.WriteFile(tmp.Name(), []byte(f.Content), perm); err != nil {
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return "", err
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}
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if err := tmp.Close(); err != nil {
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return "", err
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}
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// Ensure the permissions are as requested (since WriteFile can be affected by sticky bit)
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if err := os.Chmod(tmp.Name(), perm); err != nil {
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return "", err
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}
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if f.Owner != "" {
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// We shell out since we don't have a way to look up unix groups natively
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cmd := exec.Command("chown", f.Owner, tmp.Name())
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if err := cmd.Run(); err != nil {
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return "", err
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}
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}
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if err := os.Rename(tmp.Name(), fullpath); err != nil {
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return "", err
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}
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return fullpath, nil
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}
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func EnsureDirectoryExists(dir string) error {
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info, err := os.Stat(dir)
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if err == nil {
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if !info.IsDir() {
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return fmt.Errorf("%s is not a directory", dir)
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}
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} else {
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err = os.MkdirAll(dir, 0755)
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if err != nil {
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return err
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}
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}
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return nil
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}
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