The purpose of this Docker image is to be able to build Buildroot based software inside a container running this image.
This includes running the scripts defined by buildroot-layer: source-prepare.rb and build.rb.
The image is based on Ubuntu 20.04 LTS.
In order to use the dr script from the docker-run repository, a file called .docker.env must be present
somewhere between the current directory and the root of the file system.
This repository contains a .docker.env file that can be used for this purpose.
Using the dr script enables automatic download of the docker image from a container repository.
Docker images executes as root by default, but Buildroot recommends to run all commands as a regular user and
this is why all commands are executed via the entrypoint.sh file.
The .docker.env file must add user and uid in the environment like this:
MCHP_DOCKER_PARAMS="... -e BLD_USER=$(id -un) -e BLD_UID=$(id -u) ..."
entrypoint.sh creates a user from these environment variables and allows the user to sudo without password.
At last the command is executed as this user.