Insert line at start of file with Ansible

Question

You can insert a line at the end of a file or before/after some regex with lineinfile. But how do I insert a line at the start of a file?

Answer 1

From the link to the module manual you included in the question:

insertbefore　　Used with state=present. If specified, the line will be inserted before the last match of specified regular expression. A value is available; BOF for inserting the line at the beginning of the file. If specified regular expression has no matches, the line will be inserted at the end of the file. May not be used with backrefs.

So:

- lineinfile:
    path: path/to/file
    insertbefore: BOF
    line: my_line