// Download and write files atomically to the file system
-// Copyright (C) 2019 Simon Ruderich
+// Copyright (C) 2019-2021 Simon Ruderich
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
"syscall"
"time"
+ "github.com/google/renameio"
"github.com/pkg/errors"
)
t = zero // force download
}
- status, body, err := fetchIfModified(file.Url, file.CA, &t)
+ oldT := t
+ status, body, err := fetchIfModified(file.Url,
+ file.Username, file.Password, file.CA, &t)
if err != nil {
return err
}
if status == http.StatusNotModified {
+ if oldT.IsZero() {
+ return fmt.Errorf("status code 304 " +
+ "but did not send If-Modified-Since")
+ }
log.Printf("%q -> %q: not modified", file.Url, file.Path)
return nil
}
return fmt.Errorf("refusing to write empty file")
}
- // Write the file in an atomic fashion by creating a temporary file
- // and renaming it over the target file
-
- dir := filepath.Dir(file.Path)
- name := filepath.Base(file.Path)
-
- f, err := ioutil.TempFile(dir, "tmp-"+name+"-")
+ f, err := renameio.TempFile(filepath.Dir(file.Path), file.Path)
if err != nil {
return err
}
- defer os.Remove(f.Name())
- defer f.Close()
+ defer f.Cleanup()
// Apply permissions/user/group from the target file but remove the
// write permissions to discourage manual modifications, use Stat
if err != nil {
return err
}
- err = f.Sync()
+ err = f.CloseAtomicallyReplace()
if err != nil {
return err
}
- return os.Rename(f.Name(), file.Path)
+ return syncPath(filepath.Dir(file.Path))
}