move old nixos-config over here

common/podman.nix

@@ -0,0 +1,48 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  inherit (lib) mkIf mkEnableOption;
+  cfg = config.shelman.podman;
+in
+{
+  options.shelman.podman.enable = mkEnableOption "Podman";
+
+  config = mkIf cfg.enable {
+    environment.extraInit = ''
+      if [ -z "$DOCKER_HOST" -a -n "$XDG_RUNTIME_DIR" ]; then
+        export DOCKER_HOST="unix://$XDG_RUNTIME_DIR/podman/podman.sock"
+      fi
+    '';
+
+    environment.systemPackages = with pkgs; [
+      docker-compose
+      podman-compose
+    ];
+
+    virtualisation = {
+      containers = {
+        enable = true;
+        storage.settings = {
+          storage = {
+            driver = "overlay";
+            runroot = "/run/containers/storage";
+            graphroot = "/var/lib/containers/storage";
+            rootless_storage_path = "/tmp/containers-$USER";
+            options.overlay.mountopt = "nodev,metacopy=on";
+          };
+        };
+      };
+
+      oci-containers.backend = "podman";
+      podman = {
+        enable = true;
+        dockerCompat = true;
+      };
+    };
+  };
+}