nix-configs/modules/services/authentik.nix

{
  pkgs,
  inputs,
  lib,
  config,
  ...
}:
with lib;
let
  cfg = config.xyno.services.authentik;
  defaultAppOptions = {
    options = {
      name = mkOption {
        type = types.str;
      };
      group = mkOption {
        type = types.nullOr types.str;
        default = null;
      };
      groups = mkOption {
        type = types.listOf types.str;
        default = [ ];
      };
      meta_description = mkOption {
        type = types.nullOr types.str;
        default = null;
      };
      meta_icon = mkOption {
        type = types.nullOr types.str;
        default = null;
      };
      meta_launch_url = mkOption {
        type = types.nullOr types.str;
        default = null;
      };
      meta_publisher = mkOption {
        type = types.nullOr types.str;
        default = null;
      };
    };
  };

  terrraformStateDir = "/var/lib/authentik-terraform-config";
  environmentFileDir = "/run/authentik-terraform-config";
  terranixConfig = inputs.terranix.lib.terranixConfiguration {
    system = pkgs.system;
    modules = [
      ./authentik/provider.nix
      {
        inherit (cfg)
          oauthApps
          ldapApps
          proxyApps
          url
          insecure
          ;
        stateFile = "${terrraformStateDir}/state.tfstate";
      }
    ];
  };
in
{
  options.xyno.services.authentik.enable = mkEnableOption "enables the authentik SSO thing";
  options.xyno.services.authentik.oauthApps = mkOption {
    default = { };
    type = types.attrsOf (
      types.submodule (
        { name, ... }:
        ({
          options = {
            environmentFile = mkOption {
              type = types.str;
              default = "${environmentFileDir}/${name}_environment";
            };
          }
          // defaultAppOptions.options;
        })
      )
    );
  };
  options.xyno.services.authentik.ldapApps = mkOption {
    default = { };
    type = types.attrsOf (types.submodule (defaultAppOptions));
  };
  options.xyno.services.authentik.proxyApps = mkOption {
    default = { };
    type = types.attrsOf (
      types.submodule ({
        options = {
          externalHost = mkOption {
            type = types.str;
          };
        }
        // defaultAppOptions.options;
      })
    );
  };
  options.xyno.services.authentik.url = mkOption {
    type = types.str;
    default = "https://auth.hailsatan.eu";
  };
  options.xyno.services.authentik.insecure = mkOption {
    type = types.bool;
    default = false;
  };
  options.xyno.services.authentik.after = mkOption {
    type = types.listOf types.str;
    default = [];
  };
  config = lib.mkIf cfg.enable {
    environment.etc."authentik-config/config.tf.json".source = terranixConfig;
    xyno.impermanence.directories = [
      terrraformStateDir
    ];
    services.authentik = {
      enable = true;
      createDatabase = true;
      environmentFile = config.sops.secrets."authentik/env".path;
      settings = {
        disable_startup_analytics = true;
      };
    };
    systemd.services.authentik.after = cfg.after;
    systemd.services.authentik-ldap.after = [ "authentik-config.service" ];
    systemd.services.authentik-ldap.environment.AUTHENTIK_LISTEN__METRICS = "[::1]:9302";
    services.authentik-ldap = {
      environmentFile = "${environmentFileDir}/ldap_config";
      enable = true;
    };
    systemd.services.authentik-proxy.after = [ "authentik-config.service" ];
    systemd.services.authentik-proxy.environment.AUTHENTIK_LISTEN__HTTP = "[::1]:9001";
    systemd.services.authentik-proxy.environment.AUTHENTIK_LISTEN__METRICS = "[::1]:9301";
    services.authentik-proxy = {
      enable = true;
      environmentFile = "${environmentFileDir}/proxy_config";
    };

    systemd.services.authentik-config = {
      after = [ "authentik.service" ];
      wantedBy = [ "multi-user.target" ];
      wants = [ "network-online.target" ];
      before = [
        "authentik-ldap.service"
        "authentik-proxy.service"
      ];
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = true;
        EnvironmentFile = [ config.services.authentik.environmentFile ];
        Restart = "on-failure";
        RestartSec = 30;
        StateDirectory = "authentik-config";
      };
      script =
        let
          opentofu = pkgs.opentofu.withPlugins (p: [
            inputs.authentik.packages.${pkgs.system}.terraform-provider-authentik
          ]);
        in
        ''
          set -xeuo pipefail
          umask u=rw,go=
          export PATH=$PATH:${opentofu}/bin:${pkgs.curl}/bin
          cd $STATE_DIRECTORY
          cp ${terranixConfig} ./main.tf.json
          export AUTHENTIK_URL=${cfg.url}
          export AUTHENTIK_INSECURE=${toString cfg.insecure}
          export AUTHENTIK_TOKEN=$AUTHENTIK_BOOTSTRAP_TOKEN

          tofu init
          tofu validate || exit 1

          while [[ "$(curl -L -s -o /dev/null -I -w "%{http_code}" ''${AUTHENTIK_URL}/api/v3/flows/instances/)" =~ (502|000) ]]; do
            echo "[+] Authentik still starting, sleeping for 2s"
            sleep 2
          done

          tofu apply -auto-approve

          tofu show -state

          mkdir ${environmentFileDir}
          tofu output -show-sensitive -raw proxy_config > ${environmentFileDir}/proxy_config
          cat ${environmentFileDir}/proxy_config
          tofu output -show-sensitive -raw ldap_config > ${environmentFileDir}/ldap_config
          ${concatStringsSep "\n" (
            mapAttrsToList (
              n: v: "tofu output -show-sensitive -raw ${n}_environment > ${v.environmentFile}"
            ) cfg.oauthApps
          )}
        '';

    };
    sops.secrets."authentik/env" = {
      sopsFile = ../../instances/${config.networking.hostName}/secrets/authentik.yaml;
    };

    services.caddy.extraConfig = ''
      (reverse_proxy_auth) {
        route {
        # always forward outpost path to actual outpost
          reverse_proxy /outpost.goauthentik.io/* http://[::1]:9001 {
          }
          forward_auth http://[::1]:9001 {
            uri /outpost.goauthentik.io/auth/caddy
            copy_headers X-Authentik-Username X-Copyparty-Group X-Authentik-Groups X-Authentik-Entitlements X-Authentik-Email X-Authentik-Name X-Authentik-Uid X-Authentik-Jwt X-Authentik-Meta-Jwks X-Authentik-Meta-Outpost X-Authentik-Meta-Provider X-Authentik-Meta-App X-Authentik-Meta-Version X-Grafana-Role
          }
          reverse_proxy {args[:]}
        }
    '';
    xyno.services.monitoring.exporters.authentik = 9300;
    xyno.services.monitoring.exporters.authentik-proxy = 9301;
    xyno.services.monitoring.exporters.authentik-ldap = 9302;

  };
}