b.stefanuk.ca

Appearance

Using Docker with Nix Flakes ​

Docker Image ​

You can easily build a docker image using the dockerTools.buildImage attribute provided by Nixpkgs. More details can be found at Nixpkgs Manual: dockerTools.

Building a Docker image with Nix provides the benefit of reproducibility.

For example an image with the following derivation.

sh
packages = {
	project-name = pkgs.stdenv.mkDerivation {
		#...
	};
	docker-image = pkgs.dockerTools.buildImage {
	  name = "project-name";
	  created = "now";
	  copyToRoot = pkgs.buildEnv {
	    name = "image-root";
	    paths = [ self.packages.${system}.project-name ];
	    pathsToLink = [ "/bin" ];
	  };
	  config = {
	    Cmd = [ "/bin/project-name" ];
	  };
	};
};
packages = {
	project-name = pkgs.stdenv.mkDerivation {
		#...
	};
	docker-image = pkgs.dockerTools.buildImage {
	  name = "project-name";
	  created = "now";
	  copyToRoot = pkgs.buildEnv {
	    name = "image-root";
	    paths = [ self.packages.${system}.project-name ];
	    pathsToLink = [ "/bin" ];
	  };
	  config = {
	    Cmd = [ "/bin/project-name" ];
	  };
	};
};

Then, in a terminal, run

nix build .#project-image
nix build .#project-image

This creates a symbolic link to a Tarball named result that can be loaded into Docker. Load this image using docker load

sh
docker load < result

# Check to ensure the image is present
docker images
docker load < result

# Check to ensure the image is present
docker images

And finally, you can run the image

sh
docker run project-name:df8356kle02k67654
docker run project-name:df8356kle02k67654

You may optionally use buildLayeredImage instead of buildImage when creating the Docker image.

Docker Shell Image ​

Use dockerTools.buildNixShellImage to create Dockerized developer environments.

docker run -it --rm -v .:/build/cxx-example nix_test_app-env:latest
docker run -it --rm -v .:/build/cxx-example nix_test_app-env:latest

Upload Image to DockerHub ​

The below commands are approximate and may not be correct

docker login --username <username> the-registry-url.com
docker tag project-name:latest the-registry-url.com/project-name:latest
docker push the-registry-url.com/project-name:latest
docker login --username <username> the-registry-url.com
docker tag project-name:latest the-registry-url.com/project-name:latest
docker push the-registry-url.com/project-name:latest

As with typical Docker usage, you can run an image from the remote registry using a command like

docker run the-registry-url.com/project-name:latest
docker run the-registry-url.com/project-name:latest
ESSENTIAL RESOURCES ​