docs: 1.27 release notes

Signed-off-by: Vincenzo Scamporlino <vincenzos@spotify.com>

docs/releases/v1.27.0.md

@@ -0,0 +1,83 @@
+---
+id: v1.27.0
+title: v1.27.0
+description: Backstage Release v1.27.0
+---
+
+These are the release notes for the v1.27.0 release of [Backstage](https://backstage.io/).
+
+A huge thanks to the whole team of maintainers and contributors as well as the amazing Backstage Community for the hard work in getting this release developed and done.
+
+## Highlights
+
+### Backend System Deprecations
+
+As part of the [work towards a stable 1.0 release of the new backend system](https://github.com/backstage/backstage/issues/24493), we will deprecate and move or remove several utilities from `@backstage/backend-common`. This release contains a few of these deprecations, with more to be expected in the future. The long-term goal is to completely deprecate and remove the `@backstage/backend-common` package.
+
+### Hierarchical Domains
+
+The Backstage System Model has been tweaked with the addition of a hierarchy of `Domain` entities. The change includes a new `spec.subdomainOf` property on the `Domain` entity, which can be used to express that a domain has a `partOf` (and conversely, `hasPart`) relation toward another domain.
+
+Contributed by [@dawngerpony](https://github.com/dawngerpony) and [@janogonzalez](https://github.com/janogonzalez) in [#17125](https://github.com/backstage/backstage/pull/17125).
+
+### Scaffolder workspace serialization
+
+Added experimental support for serialization of workspaces in the scaffolder. By serializing the workspace, it is possible to re-run the task in a non-sticky way. This means that the task can be restored and retried on a different scaffolder task worker.
+
+To enable this feature, set the `EXPERIMENTAL_workspaceSerialization` option to `true` in the `scaffolder` section of the `app-config.yaml` file:
+
+```yaml
+scaffolder:
+  EXPERIMENTAL_workspaceSerialization: true
+```
+
+Contributed by [@acierto](https://github.com/acierto) in [#24570](https://github.com/backstage/backstage/pull/24570).
+
+### Scaffolder `notification:send` action
+
+The new `notification:send` action allows sending notifications from templates. This can be used to send notifications to users when executing a template. Please note that the notifications system is still under development.
+
+To install this action, add the new module to your backend:
+
+```diff
++ backend.add(import('@backstage/plugin-scaffolder-backend-module-notifications'));
+```
+
+Contributed by [@drodil](https://github.com/drodil) in [#24588](https://github.com/backstage/backstage/pull/24588).
+
+### Backend Authentication
+
+The requirement to configure a secret for backend authentication in production has been removed. It is now only needed if you rely on the [legacy authentication mechanism](https://backstage.io/docs/auth/service-to-service-auth#external-callers-legacy). If you don’t configure any secrets you will also not be able to generate tokens with the `TokenManager` service, although use of this service is discouraged as it has been replaced by the `AuthService`.
+
+### User Authentication
+
+The `auth` backend plugin now provides an `authOwnershipResolutionExtensionPoint` that lets you override the default ownership resolution used by sign-in resolvers. This allows you to customize this logic for all sign-in resolvers without replacing them.
+
+Contributed by [@drodil](https://github.com/drodil) in [#22765](https://github.com/backstage/backstage/pull/22765).
+
+### Events support for GitLab Entity and Org Discovery
+
+The `GitlabDiscoveryEntityProvider` and `GitlabOrgDiscoveryEntityProvider` can now be configured to receive events from GitLab. This allows for the automatic discovery of entities in Backstage when groups or users are created or updated in GitLab.
+
+Contributed by [@elaine-mattos](https://github.com/elaine-mattos) in [#23373](https://github.com/backstage/backstage/pull/23373).
+
+## Security Fixes
+
+This release does not contain any security fixes.
+
+## Upgrade path
+
+We recommend that you keep your Backstage project up to date with this latest release. For more guidance on how to upgrade, check out the documentation for [keeping Backstage updated](https://backstage.io/docs/getting-started/keeping-backstage-updated).
+
+## Links and References
+
+Below you can find a list of links and references to help you learn about and start using this new release.
+
+- [Backstage official website](https://backstage.io/), [documentation](https://backstage.io/docs/), and [getting started guide](https://backstage.io/docs/getting-started/)
+- [GitHub repository](https://github.com/backstage/backstage)
+- Backstage's [versioning and support policy](https://backstage.io/docs/overview/versioning-policy)
+- [Community Discord](https://discord.gg/backstage-687207715902193673) for discussions and support
+- [Changelog](https://github.com/backstage/backstage/tree/master/docs/releases/v1.27.0-changelog.md)
+- Backstage [Demos](https://backstage.io/demos), [Blog](https://backstage.io/blog), [Roadmap](https://backstage.io/docs/overview/roadmap) and [Plugins](https://backstage.io/plugins)
+
+Sign up for our [newsletter](https://info.backstage.spotify.com/newsletter_subscribe) if you want to be informed about what is happening in the world of Backstage.

microsite/docusaurus.config.ts

@@ -216,7 +216,7 @@ const config: Config = {
           position: 'left',
         },
         {
-          to: 'docs/releases/v1.26.0',
+          to: 'docs/releases/v1.27.0',
           label: 'Releases',
           position: 'left',
         },

microsite/sidebars.json

@@ -1,6 +1,7 @@
 {
   "releases": {
     "Release Notes": [
+      "releases/v1.27.0",
       "releases/v1.26.0",
       "releases/v1.25.0",
       "releases/v1.24.0",