nixos/keycloak: update options for release 25.0.0

Reference: https://www.keycloak.org/docs/25.0.0/upgrading/

nixos/doc/manual/release-notes/rl-2205.section.md

@@ -453,7 +453,7 @@ In addition to numerous new and upgraded packages, this release has the followin
 
     The new names are as follows:
     - `bindAddress`: [`services.keycloak.settings.http-host`](#opt-services.keycloak.settings.http-host)
-    - `forceBackendUrlToFrontendUrl`: [`services.keycloak.settings.hostname-strict-backchannel`](#opt-services.keycloak.settings.hostname-strict-backchannel)
+    - `forceBackendUrlToFrontendUrl`: `services.keycloak.settings.hostname-strict-backchannel`
     - `httpPort`: [`services.keycloak.settings.http-port`](#opt-services.keycloak.settings.http-port)
     - `httpsPort`: [`services.keycloak.settings.https-port`](#opt-services.keycloak.settings.https-port)
 

nixos/doc/manual/release-notes/rl-2411.section.md

@@ -87,6 +87,9 @@
   services.portunus.ldap.package = pkgs.openldap.override { libxcrypt = pkgs.libxcrypt-legacy; };
   ```
 
+- `keycloak` was updated to version 25, which introduces new hostname related options.
+  See [Upgrading Guide](https://www.keycloak.org/docs/25.0.1/upgrading/#migrating-to-25-0-0) for instructions.
+
 - The `tracy` package no longer works on X11, since it's moved to Wayland
   support, which is the intended default behavior by Tracy maintainers.
   X11 users have to switch to the new package `tracy-x11`.

nixos/modules/services/web-apps/keycloak.md

@@ -68,13 +68,11 @@ to `/auth`. See the option description
 for more details.
 :::
 
-[](#opt-services.keycloak.settings.hostname-strict-backchannel)
-determines whether Keycloak should force all requests to go
-through the frontend URL. By default,
-Keycloak allows backend requests to
-instead use its local hostname or IP address and may also
-advertise it to clients through its OpenID Connect Discovery
-endpoint.
+[](#opt-services.keycloak.settings.hostname-backchannel-dynamic)
+Keycloak has the capability to offer a separate URL for backchannel requests,
+enabling internal communication while maintaining the use of a public URL
+for frontchannel requests. Moreover, the backchannel is dynamically
+resolved based on incoming headers endpoint.
 
 For more information on hostname configuration, see the [Hostname
 section of the Keycloak Server Installation and Configuration

nixos/modules/services/web-apps/keycloak.nix

@@ -328,8 +328,7 @@ in
             };
 
             hostname = mkOption {
-              type = nullOr str;
-              default = null;
+              type = str;
               example = "keycloak.example.com";
               description = ''
                 The hostname part of the public URL used as base for
@@ -340,16 +339,13 @@ in
               '';
             };
 
-            hostname-strict-backchannel = mkOption {
+            hostname-backchannel-dynamic = mkOption {
               type = bool;
               default = false;
               example = true;
               description = ''
-                Whether Keycloak should force all requests to go
-                through the frontend URL. By default, Keycloak allows
-                backend requests to instead use its local hostname or
-                IP address and may also advertise it to clients
-                through its OpenID Connect Discovery endpoint.
+                Enables dynamic resolving of backchannel URLs,
+                including hostname, scheme, port and context path.
 
                 See <https://www.keycloak.org/server/hostname>
                 for more information about hostname configuration.
@@ -482,12 +478,20 @@ in
             message = "Setting up a local PostgreSQL db for Keycloak requires `standard_conforming_strings` turned on to work reliably";
           }
           {
-            assertion = cfg.settings.hostname != null || cfg.settings.hostname-url or null != null;
-            message = "Setting the Keycloak hostname is required, see `services.keycloak.settings.hostname`";
+            assertion = cfg.settings.hostname-url or null == null;
+            message = ''
+              The option `services.keycloak.settings.hostname-url' has been removed.
+              Set `services.keycloak.settings.hostname' instead.
+              See [New Hostname options](https://www.keycloak.org/docs/25.0.0/upgrading/#new-hostname-options) for details.
+            '';
           }
           {
-            assertion = !(cfg.settings.hostname != null && cfg.settings.hostname-url or null != null);
-            message = "`services.keycloak.settings.hostname` and `services.keycloak.settings.hostname-url` are mutually exclusive";
+            assertion = cfg.settings.hostname-strict-backchannel or null == null;
+            message = ''
+              The option `services.keycloak.settings.hostname-strict-backchannel' has been removed.
+              Set `services.keycloak.settings.hostname-backchannel-dynamic' instead.
+              See [New Hostname options](https://www.keycloak.org/docs/25.0.0/upgrading/#new-hostname-options) for details.
+            '';
           }
         ];