Very Fast Docker Image Build - Without Context

I use docker images to provide the environment for development. My nodejs is installed only inside the docker image. That means I always map my working directory into the container. This means I don't need to send no build context to the docker deamon.

Before my slow docker build started like this:
Sending build context to Docker daemon 88.67MB VERY SLOW
that happens when you use
docker build -t ${IMAGE_NAME} -f Dockerfile . and it takes forever.

I got the fast docker build after I discovered in the docker docs, that one can also not send the context, now the context is tiny:
Sending build context to Docker daemon 2.048kB VERY FAST.
Build your image like this:
docker build -t ${IMAGE_NAME} - < Dockerfile
Remember: you get no context in the container, so either you don't need it or you map in volumes, or you know ...