Data recovery

[egorps]

Send data to a file when an error occurs.

[lomignet]

make sure file name is unique across runs by suffixing it with pid + timestamp

suffix = '.' + str(os.getpid()) + '.' + datetime.datetime.utcnow().strftime('%Y%m%d_%H%M%S')
file = tempfile.NamedTemporaryFile(dir=NeedToGetFromParam, mode='w', delete=false, suffix=suffix)
self.recover_file = file.name

[lomignet]

Hi John,

This is a great feature, there are only 2 things on which I would like your thoughts:

1. I commented a bit on your code. Basically, I would like to see the top dir of the drained file to be configurable. On our setup (not exceptional I believe), /tmp is a small memory tmpfs. This is thus non persistent, and could be filled quite quickly. My (maybe dirty) idea would be to make drain_to_file a str instead of a boolean, this str would be the root dir of the drainfile. None would have the meaning of the current False.

2. According to the doc, using mkdtemp, "The directory is readable, writable, and searchable only by the creating user ID.". It feels safer for forensics to use NamedTemporaryFile "the file is guaranteed to have a visible name in the file system". This has the added benefit of allowing mutiple files for multiple runs to be saved, as I added on the comments on my code.

Thanks a lot for your PR.