nixos/tests/docker-tools: check layer sharing with buildLayeredImage

Adapted from grahamc's blog post on layered Docker images in Nix:

https://grahamc.com/blog/nix-and-layered-docker-images

1 files changed, 8 insertions, 0 deletions

diff --git a/pkgs/build-support/docker/examples.nix b/pkgs/build-support/docker/examples.nix
index ac21be907b8..29eea33a7e1 100644
--- a/pkgs/build-support/docker/examples.nix
+++ b/pkgs/build-support/docker/examples.nix
@@ -226,4 +226,12 @@ rec {
     '';
   };
 
+  # 14. Create another layered image, for comparing layers with image 10.
+  another-layered-image = pkgs.dockerTools.buildLayeredImage {
+    name = "another-layered-image";
+    tag = "latest";
+    config.Cmd = [ "${pkgs.hello}/bin/hello" ];
+    contents = [ pkgs.hello ];
+  };
+
 }