From 8288d3cc882fccee60b4717199a42e1c47703bd8 Mon Sep 17 00:00:00 2001
From: niten <niten@fudo.org>
Date: Tue, 12 Sep 2023 11:49:23 -0700
Subject: [PATCH] initial checkin

---
 flake.nix         |  12 ++++
 matrix-module.nix | 139 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 151 insertions(+)
 create mode 100644 flake.nix
 create mode 100644 matrix-module.nix

diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..e30b758
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,12 @@
+{
+  description = "Matrix configuration module.";
+
+  inputs = { nixpkgs.url = "nixpkgs/nixos-23.05"; };
+
+  outputs = { self, nixpkgs, ... }: {
+    nixosModules = rec {
+      default = matrix;
+      matrix = { ... }: { imports = [ ./matrix-module.nix ]; };
+    };
+  };
+}
diff --git a/matrix-module.nix b/matrix-module.nix
new file mode 100644
index 0000000..8c7f717
--- /dev/null
+++ b/matrix-module.nix
@@ -0,0 +1,139 @@
+{ config, lib, pkgs, ... }@toplevel:
+
+with lib;
+let
+  cfg = config.fudo.services.matrix;
+
+  hostname = config.instance.hostname;
+
+  openIdConfig = pkgs.toJSON "matrix-openid.yaml" {
+    oidc_providers = [{
+      idp_id = cfg.openid.provider;
+      idp_name = cfg.openid.provider;
+      discover = true;
+      issuer = "https://authentik.fudo.org/application/o/matrix/";
+      client_id = cfg.openid.client-id;
+      client_secret = cfg.openid.client-secret;
+      scopes = [ "openid" "profile" "email" ];
+      user_mapping_provider.config = {
+        localpart_template = "{{ user.preferred_username }}";
+        display_name_template = "{{ user.name | capitalize }}";
+      };
+    }];
+  };
+
+in {
+  options.fudo.services.matrix = with types; {
+    enable = mkEnableOption "Enable Matrix server.";
+
+    state-directory = mkOption {
+      type = str;
+      description = "Directory at which to store server state data.";
+    };
+
+    server-name = mkOption {
+      type = str;
+      description = ''
+        Hostname at which the server can be reached.
+
+        Also the tag at the end of the username: @user@my-server.com.
+
+        Can be redirected to the actual server. See:
+
+        https://nixos.org/manual/nixos/stable/#module-services-matrix-synapse
+      '';
+    };
+
+    hostname = mkOption {
+      type = str;
+      description = "Hostname at which the server can be reached.";
+      default = toplevel.config.services.matrixContainer.server-name;
+    };
+
+    openid = {
+      provider = mkOption {
+        type = str;
+        description = "Name of the authentication provider.";
+      };
+
+      client-id = mkOption {
+        type = str;
+        description = "OpenID Client ID.";
+      };
+
+      client-secret = mkOption {
+        type = str;
+        description = "OpenID Client Secret.";
+      };
+    };
+  };
+
+  config = {
+    fudo.secrets.host-secrets."${hostname}".matrixOpenIdConfig = {
+      source-file = openIdConfig;
+      target-file = "/run/matrix/openid.cfg";
+      user = config.systemd.services.matrix-synapse.serviceConfig.User;
+    };
+
+    services = {
+      matrix-synapse = {
+        enable = true;
+        withJemalloc = true;
+        settings = {
+          server_name = cfg.server-name;
+          public_baseurl = "https://${cfg.hostname}";
+          dynamic_thumbnails = true;
+          max_upload_size = "100M";
+          media_store_path = "${cfg.state-directory}/media";
+          signing_key_path = "${cfg.state-directory}/signing.key";
+          listeners = [{
+            port = cfg.port;
+            bind_addresses = [ "127.0.0.1" "::1" ];
+            type = "http";
+            tls = false;
+            x_forwarded = true;
+            resources = [{
+              names = [ "client" "federation" ];
+              compress = true;
+            }];
+          }];
+          database = {
+            name = "sqlite3";
+            args.database = "${cfg.state-directory}/database/data.db";
+          };
+        };
+        extraConfigFile = [ hostSecrets.matrixOpenIdConfig.target-file ];
+      };
+
+      nginx = {
+        enable = true;
+        virtualHosts = {
+          "${cfg.server-name}" = let
+            mkWellKnown = data: ''
+              add_header Content-Type application/json;
+              add_header Access-Control-Allow-Origin *;
+              return 200 '${builtins.toJSON data}';
+            '';
+          in {
+            enableACME = true;
+            forceSSL = true;
+            locations."/.well-known/matrix/server".extraConfig =
+              mkWellKnown { "m.server" = "https://${cfg.hostname}:443"; };
+            locations."/.well-known/matrix/client".extraConfig = mkWellKnown {
+              "m.homeserver".base_url = "https://${cfg.hostname}";
+            };
+          };
+          "${cfg.hostname}" = {
+            enableACME = true;
+            forceSSL = true;
+            locations."/" = {
+              proxyPass = "http://localhost:${toString cfg.port}";
+              proxyWebsockets = true;
+              recommendedProxySettings = true;
+            };
+          };
+        };
+      };
+    };
+  };
+}