If two cutters modify a video at the same time, youtube may respond with a 409 to one of them.
We want to treat that as a retryable error, and ideally let another cutter finish it instead.
In python 3, file.write() may do a partial write and returns the number of characters written.
In order to not lose data, we need to wrap every instance of file.write() with our new
common.writeall() wrapper that loops until the data is actually written.
Check that open() calls for reading and writing use binary modes
Use alpine version with py3-pip package
Use python3 in Dockerfile CMD
Remove sys.setdefaultencoding() "hack"
Simplify ensure_directory() in common.common package
Instead of handling each error condition seperately,
we raise an UploadError which includes whether it's retryable.
The advantage of this is that upload backends can also raise an UploadError
to indicate two conditions it currently cannot:
That an error is unretryable
That an error is retryable, even if the row was already in finalizing
Under this scheme, errors while cutting become unretryable UploadErrors,
and unhandled exceptions in uploading become retryable UploadErrors if
the row is not yet finalizing only.
Only support iterable of string, not file-like or string.
This is a minor usability loss but we only call this from one place anyway
and it's always an iterable of string.
Cutter now takes a 'config' arg which is a json blob with detail
on each upload location. This is a bit nasty if you're trying to run it manually
but was the easiest way to transfer the config data from docker-compose.jsonnet
to the actual application.