~$ yamllint preconf.yaml
preconf.yaml
  1:2       warning  missing starting space in comment  (comments)
  2:1       warning  missing document start "---"  (document-start)
  4:24      error    syntax error: mapping values are not allowed here
  5:81      error    line too long (100 > 80 characters)  (line-length)
  11:81     error    line too long (92 > 80 characters)  (line-length)
  14:1      error    too many blank lines (1 > 0)  (empty-lines)
