Feature request: parameterize Docker image with environment variables, so consumer doesn't need to know Docker internals

[mieubrisse]

Currently, a user of the Gecko Docker image needs to know specifics about the internals of the image (e.g. where the binary is located). If the CMD of the Dockerfile is parameterized with Bash environment variables, an API is created that the user can use to start up a Gecko node in Docker with various parameters without needing to know any specifics about the internals of the Docker image.