Make the Nix-based Docker container work on non-NixOS (#3109)

On NixOS, the CUDA driver shim gets mounted on /run/opengl-driver,
where Nix packages expect the shim to be. However, on other
distributions, some FHS paths are mounted. This is a small change
to make the dynamic loader find the shim.

Author: danieldk

flake.nix

@@ -176,11 +176,15 @@
             '';
           };
 
-          dockerImage = pkgs.callPackage nix/docker.nix {
+          # Use plain nixpkgs without overlays for dockerTools. dockerTools
+          # uses a Python package for computing the layers from the transitive
+          # closure. However, this needs a lot of rebuilds due to our overlay.
+
+          dockerImage = nixpkgs.legacyPackages.${system}.callPackage nix/docker.nix {
             text-generation-inference = default;
           };
 
-          dockerImageStreamed = pkgs.callPackage nix/docker.nix {
+          dockerImageStreamed = nixpkgs.legacyPackages.${system}.callPackage nix/docker.nix {
             text-generation-inference = default;
             stream = true;
           };

nix/docker.nix

@@ -18,6 +18,10 @@ build {
     Env = [
       "HF_HOME=/data"
       "PORT=80"
+      # The CUDA container toolkit will mount the driver shim into the
+      # container. We just have to ensure that the dynamic loader finds
+      # the libraries.
+      "LD_LIBRARY_PATH=/usr/lib64"
     ];
 
   };