code: def insert_line_in_file_after_regex(path, line, after_regex, use_sudo=False):
      
  
      tmpfile = str(uuid.uuid4())
      get_file(path, tmpfile, use_sudo=use_sudo)
      with open(tmpfile) as f:
          original = f.read()
  
      if line not in original:
          outfile = str(uuid.uuid4())
          with open(outfile, 'w') as output:
              for l in original.split('\n'):
                  output.write(l + '\n')
                  if re.match(after_regex, l) is not None:
                      output.write(line + '\n')
  
          upload_file(local_path=outfile,
                      remote_path=path,
                      use_sudo=use_sudo)
          os.unlink(outfile)
      os.unlink(tmpfile)
docs: inserts a line in the middle of a file