aws s3 sync doesn't guess mimetype for .properties files

[mblakele]

aws-cli/1.10.56 Python/2.7.10 Darwin/15.6.0 botocore/1.4.46

When using aws s3 sync on *.properties files, the metadata content-type ends up with a value suitable for binary. It would be nice to have text/x-java-properties or another text/* type.

Workaround: use --content-type text/x-java-properties. However the sync origin may have more than one file type.

[JordonPhillips]

We use the python mimetypes library to guess the type, if it can't guess then there's not much we can do. You might be able to make that request on python itself, but it will necessarily require updating python versions.

[mblakele]

Consider falling back on python-magic in guess_content_type if mimetypes.guess_type returns None.

>>> import magic
>>> mime = magic.Magic(mime=True)
>>> mime.from_filename("/tmp/test.properties")
>>> mime.from_file("/tmp/test.properties")
'text/plain'

That would be an improvement on the current behavior.