Oak provides a fileutil package which allows for the embedding of binary data such as images and audio in an oak binary with the help of tools like go-bindata.
Through supplying fileutil.BindataFn, which matches the signature of the Asset function that go-bindata supplies, and fileutil.BindataDir, parallel to AssetDir, Oak can be instructed to search within stored binary data before looking at real local files when attempting to open asset files.
Oak provides the utility function oak.SetBinaryPayload to set both of these values at once.
If you yourself are accessing assets, and not using oak's loaders, you can also check the binary functions first by using fileutil.Open instead of os.Open, and so on for fileutil.ReadDir and fileutil.ReadFile.