Fwiw, this regex breaks on some chef logs I have laying around, that look like the form of:

```
[Thu, 24 May 2012 19:59:49 +0000] INFO: Chef Run complete in 142.645817 seconds
```
Yes, I know this particular log entry is old, but it is an example of the format used by chef 10. I'd recommend a comment saying Chef 11 required.

Seems to work fine for me with Chef 11 logs though.