Docker and postgres config

hosts/common/optional/docker/default.nix

@@ -0,0 +1,20 @@
+{ inputs, ... }: {
+
+  imports = [ inputs.arion.nixosModules.arion ];
+  # Arion works with Docker, but for NixOS-based containers, you need Podman
+  # since NixOS 21.05.
+  virtualisation = {
+    podman = {
+      enable = true;
+      defaultNetwork.settings.dns_enabled = true;
+    };
+    docker = {
+      storageDriver = "btrfs";
+      rootless = {
+        enable = true;
+        setSocketVariable = true;
+      };
+    };
+  };
+
+}

hosts/common/optional/docker/postgres.nix

@@ -0,0 +1,29 @@
+{ pkgs, ... }:
+{
+  virtualisation.arion = {
+    backend = "docker";
+    projects = {
+      "db".settings.services."db".service = {
+        image = "postgres:16";
+        restart = "unless-stopped";
+        environment = {
+          POSTGRES_PASSWORD = "balls1234";
+          POSTGRES_USER = "admin";
+          POSTGRES_DATABASE = "test_db";
+        };
+        ports = [ "5432:5432" ];
+        volumes = [
+          "/mnt/postgres/data:/var/lib/postgres/data"
+          "${pkgs.writeScript "load_extensions" ''
+            psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" <<EOF
+            create extension postgis;
+            select * FROM pg_extension;
+            EOF
+           ''}:/docker-entrypoint-initdb.d/"
+        ];
+      };
+    };
+  };
+
+}
+