nix: Add Docker image

Docker image has been requested for ages so let’s add it.

Author: jtojnar

flake.nix

@@ -80,6 +80,11 @@
  };
 
  packages = {
+ selfoss-docker = pkgs.callPackage ./utils/docker.nix {
+ inherit (nixpkgs.lib) nixosSystem;
+ targetPlatform = system;
+ };
+
  selfoss = pkgs.callPackage ./utils/selfoss.nix {
  src = self.outPath;
  };

utils/docker.nix

@@ -0,0 +1,86 @@
+{
+ coreutils,
+ bash,
+ util-linux,
+ dockerTools,
+ unzip,
+ lib,
+ nixosSystem,
+ targetPlatform,
+}:
+
+# We are going to abuse the NixOS module for Apache to create configuration files.
+# Then we will extract them from the instantiated system and add them to the image.
+
+let
+ # Configuration for NixOS system.
+ systemConfiguration = { config, lib, pkgs, ... }: {
+ services.httpd = {
+ enable = true;
+
+ # TODO: make this overridable? Or hidden?
+ adminAddr = "admin@selfoss";
+
+ # TODO: is root okay?
+ user = "root";
+ group = "root";
+
+ virtualHosts."selfoss" = {
+ documentRoot = "/var/www";
+ locations."/" = {
+ index = "index.php index.html";
+ };
+ };
+
+ phpPackage = pkgs.php;
+ enablePHP = true;
+ };
+ };
+
+ # Instantiate the NixOS configuration.
+ system = nixosSystem {
+ system = targetPlatform;
+
+ modules = [
+ systemConfiguration
+ ];
+ };
+
+ apacheHttpd = system.config.services.httpd.package;
+
+in
+dockerTools.buildLayeredImage {
+ name = "selfoss";
+ tag = "latest";
+
+ contents = [
+ apacheHttpd
+
+ # TODO: remove, only for debugging
+ coreutils
+ bash
+ util-linux
+ ];
+
+ # Cargo-culted from https://sandervanderburg.blogspot.com/2020/07/on-using-nix-and-docker-as-deployment.html
+ maxLayers = 100;
+
+ extraCommands = ''
+ mkdir -p var/log/httpd var/cache/httpd var/www etc/httpd
+ ${selfoss} -d var/www
+ cp ${system.config.environment.etc."httpd/httpd.conf".source} etc/httpd/httpd.conf
+ '';
+
+ config = {
+ Cmd = [ "${apacheHttpd}/bin/apachectl" "-D" "FOREGROUND" ];
+ Expose = {
+ "80/tcp" = {};
+ };
+ };
+}
+
+# TODO: add devenv image
+# NOTE: Can be run:
+# nix build -L .#selfoss-docker
+# docker load < result
+# docker run -p 8080:80/tcp -it selfoss:latest