While the try/except block does prevent most of the temp files from
persisting, if there is a non catchable exception, those temp files
continue to pollute the directory. Optionally set the temp
directory would let us write to something like /tmp, so the target
directory isn't polluted

Signed-off-by: Aaditya Dhruv <aadityadhruv@mailbox.org>

The tmpdir must be on the same filesystem to ensure an atomic operation
takes place. If this is not enforced, there could be partial writes
which can lead to partial/incorrect metrics being exported

Signed-off-by: Aaditya Dhruv <aadityadhruv@mailbox.org>