I can’t access kernel gateway in my Docker container.

The kernel gateway server listens on port 8888 by default. Make sure this internal port is exposed on an external port when starting the container. For example, if you run:

docker run -it --rm -p 9000:8888 jupyter/minimal-kernel

you can access your kernel gateway on the IP address of your Docker host an port 9000.

Kernel gateway raises an error when I use notebook-http mode.

The notebook-http mode publishes a web API defined by annotations and code in a notebook. Make sure you are specifying a path or URL of a notebook (*.ipynb) file when you launch the kernel gateway in this mode. Set the --KernelGatewayApp.seed_uri command line parameter or KG_SEED_URI environment variable to do so.