1 files changed, 90 insertions, 0 deletions
diff --git a/nix-modules/docker-nixos-modules.nix b/nix-modules/docker-nixos-modules.nix
new file mode 100644
index 0000000..47107a7
--- /dev/null
+++ b/nix-modules/docker-nixos-modules.nix
@@ -0,0 +1,90 @@
+{ nixpkgsPath ? <nixpkgs>
+, ociconfig
+, name
+, ...}:
+
+let
+  pkgs = import nixpkgsPath {};
+
+  dummyOption = with pkgs.lib; mkOption {
+    type = types.attrs;
+    default = {};
+  };
+
+  systemModule = { lib, config, ... }: {
+    options = {
+      toplevel = lib.mkOption {
+        type = lib.types.str;
+      };
+
+      systemd = with lib; {
+        services = dummyOption;
+        targets = dummyOption;
+        timers = dummyOption;
+      };
+
+      environment = dummyOption;
+      users.users = dummyOption;
+      users.groups = dummyOption;
+      meta = dummyOption;
+
+      networking.enableIPv6 = lib.mkOption {
+        type = lib.types.bool;
+        default = false;
+      };
+    };
+
+    config._module.args.pkgs = pkgs;
+  };
+
+  config = pkgs.lib.evalModules {
+    modules = [
+      systemModule
+      ociconfig
+      "${nixpkgsPath}/nixos/modules/misc/assertions.nix"
+    ];
+  };
+
+in pkgs.dockerTools.buildImage {
+  inherit name;
+
+  contents = pkgs.coreutils;
+
+  runAsRoot = (with pkgs.lib;
+    strings.concatStrings
+      (mapAttrsToList
+        (n: u: if u ? createHome && u.createHome then ("mkdir -p ${u.home}\n") else "")
+        config.config.users.users));
+
+  config = with pkgs.lib; {
+    Cmd = pkgs.writeShellScript "main-entrypoint"
+      (strings.concatStrings
+      (map (command: "${command}&")
+      (mapAttrsToList
+      (name: service:
+        (pkgs.writeShellScript
+          "systemd-script-${name}"
+          ''
+            #!${pkgs.dash.outPath}/bin/sh
+            set -ueo pipefail
+            ${if service ? preStart
+              then ''
+                echo ${escapeShellArg name}: running preStart script
+                ${service.preStart}
+              ''
+              else ""}
+            echo ${name}: starting ...
+            ${if service ? serviceConfig && service.serviceConfig ? WorkingDirectory
+              then "cd ${service.serviceConfig.WorkingDirectory}"
+              else ""}
+            ${if service ? environment
+              then (strings.concatStrings
+                    (mapAttrsToList
+                      (n: k: "export ${n}=${escapeShellArg k}\n")
+                        service.environment))
+                   + service.script
+              else ""}
+          '').outPath)
+        config.config.systemd.services)) + "\n wait");
+  };
+}