nixpkgs/nixos/tests/docker-tools.nix
Graham Christensen c88337c9ac
dockerTools.buildImage: support using a layered image in fromImage
Docker images used to be, essentially, a linked list of layers. Each
layer would have a tarball and a json document pointing to its parent,
and the image pointed to the top layer:

    imageA  ----> layerA
                    |
                    v
                  layerB
                    |
                    v
                  layerC

The current image spec changed this format to where the Image defined
the order and set of layers:

    imageA  ---> layerA
            |--> layerB
            `--> layerC

For backwards compatibility, docker produces images which follow both
specs: layers point to parents, and images also point to the entire
list:

    imageA  ---> layerA
            |      |
            |      v
            |--> layerB
            |      |
            |      v
            `--> layerC

This is nice for tooling which supported the older version and never
updated to support the newer format.

Our `buildImage` code only supported the old version, so in order for
`buildImage` to properly generate an image based on another image
with `fromImage`, the parent image's layers must fully support the old
mechanism.

This is not a problem in general, but is a problem with
`buildLayeredImage`.

`buildLayeredImage` creates images with newer image spec, because
individual store paths don't have a guaranteed parent layer. Including
a specific parent ID in the layer's json makes the output less likely
to cache hit when published or pulled.

This means until now, `buildLayeredImage` could not be the input to
`buildImage`.

The changes in this PR change `buildImage` to only use the layer's
manifest when locating parent IDs. This does break buildImage on
extremely old Docker images, though I do wonder how many of these
exist.

This work has been sponsored by Target.
2018-12-05 14:25:54 -05:00

71 lines
3.4 KiB
Nix

# this test creates a simple GNU image with docker tools and sees if it executes
import ./make-test.nix ({ pkgs, ... }: {
name = "docker-tools";
meta = with pkgs.stdenv.lib.maintainers; {
maintainers = [ lnl7 ];
};
nodes = {
docker =
{ ... }: {
virtualisation = {
diskSize = 2048;
docker.enable = true;
};
};
};
testScript =
''
$docker->waitForUnit("sockets.target");
# Ensure Docker images use a stable date by default
$docker->succeed("docker load --input='${pkgs.dockerTools.examples.bash}'");
$docker->succeed("[ '1970-01-01T00:00:01Z' = \"\$(docker inspect ${pkgs.dockerTools.examples.bash.imageName} | ${pkgs.jq}/bin/jq -r .[].Created)\" ]");
$docker->succeed("docker run --rm ${pkgs.dockerTools.examples.bash.imageName} bash --version");
$docker->succeed("docker rmi ${pkgs.dockerTools.examples.bash.imageName}");
# Check if the nix store is correctly initialized by listing dependencies of the installed Nix binary
$docker->succeed("docker load --input='${pkgs.dockerTools.examples.nix}'");
$docker->succeed("docker run --rm ${pkgs.dockerTools.examples.nix.imageName} nix-store -qR ${pkgs.nix}");
$docker->succeed("docker rmi ${pkgs.dockerTools.examples.nix.imageName}");
# To test the pullImage tool
$docker->succeed("docker load --input='${pkgs.dockerTools.examples.nixFromDockerHub}'");
$docker->succeed("docker run --rm nixos/nix:1.11 nix-store --version");
$docker->succeed("docker rmi nixos/nix:1.11");
# To test runAsRoot and entry point
$docker->succeed("docker load --input='${pkgs.dockerTools.examples.nginx}'");
$docker->succeed("docker run --name nginx -d -p 8000:80 ${pkgs.dockerTools.examples.nginx.imageName}");
$docker->waitUntilSucceeds('curl http://localhost:8000/');
$docker->succeed("docker rm --force nginx");
$docker->succeed("docker rmi '${pkgs.dockerTools.examples.nginx.imageName}'");
# An pulled image can be used as base image
$docker->succeed("docker load --input='${pkgs.dockerTools.examples.onTopOfPulledImage}'");
$docker->succeed("docker run --rm ontopofpulledimage hello");
$docker->succeed("docker rmi ontopofpulledimage");
# Regression test for issue #34779
$docker->succeed("docker load --input='${pkgs.dockerTools.examples.runAsRootExtraCommands}'");
$docker->succeed("docker run --rm runasrootextracommands cat extraCommands");
$docker->succeed("docker run --rm runasrootextracommands cat runAsRoot");
$docker->succeed("docker rmi '${pkgs.dockerTools.examples.runAsRootExtraCommands.imageName}'");
# Ensure Docker images can use an unstable date
$docker->succeed("docker load --input='${pkgs.dockerTools.examples.bash}'");
$docker->succeed("[ '1970-01-01T00:00:01Z' != \"\$(docker inspect ${pkgs.dockerTools.examples.unstableDate.imageName} | ${pkgs.jq}/bin/jq -r .[].Created)\" ]");
# Ensure Layered Docker images work
$docker->succeed("docker load --input='${pkgs.dockerTools.examples.layered-image}'");
$docker->succeed("docker run --rm ${pkgs.dockerTools.examples.layered-image.imageName}");
# Ensure building an image on top of a layered Docker images work
$docker->succeed("docker load --input='${pkgs.dockerTools.examples.layered-on-top}'");
$docker->succeed("docker run --rm ${pkgs.dockerTools.examples.layered-on-top.imageName}");
'';
})