Package mock_afero is a generated GoMock package.

GetOrDownloadMongod returns the path to the mongod binary from the tarball at the given URL.

MakeDownloadSpec returns a DownloadSpec for the current operating system.

We define these as package vars so we can override it in tests.

DownloadSpec specifies what copy of MongoDB to download.

UnsupportedMongoVersionError is used to indicate the memongo doesn't know how to download the given version of MongoDB.

UnsupportedSystemError is used to indicate that memongo does not support automatic selection of the right MongoDB binary for your system.