Add a page for Control Center login and logout links (vaadin#3748)

* Add a page for Control Center login and logout links

* Add router ignore to link

* First pass at editing.

* Second pass at editing and formatting.

---------

Co-authored-by: Russell J.T. Dyer <6652767+russelljtdyer@users.noreply.github.com>

Author: MatthewVaadin

articles/control-center/application-deployment/index.adoc

@@ -1,5 +1,5 @@
 ---
-title: Application Discovery
+title: Application Deployment
 description: How to use Control Center's Application Discovery feature.
 order: 20
 ---
@@ -82,7 +82,7 @@ In the [guibutton]*Deploy* panel on the right-hand side (as shown in the screens
 - *Application Name*: Give your application a meaningful name (e.g., `My App`).
 - *Image*: Enter the tag of the Docker image (e.g., `my-app:latest`).
 - *Replicas*: Specify the number of instances to run. The default is `1`.
-- *Hostname*: Set the external URL to access your application (e.g., `https://app.example.com`). For more information on how to choose a proper hostname, refer to the <<hostname-guidelines, Hostname Guidelines>>.
+- *Hostname*: Set the external URL to access your application (e.g., `https://app.example.com`). For more information on how to choose a proper hostname, refer to the <<hostname-guidelines#, Hostname Guidelines>>.
 - *Features*: Enable additional features like Identity Management and Localization if required.
 
 [NOTE]

articles/control-center/identity-management/index.adoc

@@ -15,15 +15,15 @@ With Control Center, you can do several things that allow you to centralize user
 - *Create & Assign Groups*: Organize users into groups, assign specific roles to the groups, and streamline permissions management.
 - *Manage Roles*: Define roles that can be used to control access to specific views or functionality in your application.
 
-Before starting, make sure you've already deployed an application as described in <<../application-deployment, Deploying a Vaadin Application with Control Center>>. 
+Before starting, make sure you've already deployed an application as described in <<../application-deployment#,Deploying a Vaadin Application with Control Center>>.
 
 
 == Creating a New User
 
 To create a new user, first select the relevant application from the [guilabel]*Application Selector*, as shown in the screenshot here. It'll display the application's dashboard.
 
 image::../application-deployment/images/app-selector.png[App Selector]
- 
+
 The dashboard provides an overview of the current user base for the selected application.
 
 image::images/app-dashboard.png[App Dashboard]
@@ -74,3 +74,8 @@ Fill in the fields to create a new group:
 
 Once the group is created, the assigned users inherit the permissions associated with the roles assigned to the group.
 
+
+== Login/Logout Links
+
+To create login and logout links or buttons in your Vaadin application, refer to the guide on <<login-logout#,Creating Login and Logout Links>>.
+

articles/control-center/identity-management/login-logout.adoc

@@ -0,0 +1,60 @@
+---
+title: Login and Logout Links
+description: How to create login and logout links or buttons using Control Center identity management security.
+order: 40
+---
+
+
+= Login & Logout Links
+
+For users to login and logout, it can be useful to provide them with a link or button. This page explains how to do that in a Vaadin application when using the <<../identity-management#,Identity Management feature>> in Control Center.
+
+
+== Adding Login
+
+To add a login link or button to a Vaadin application, you'll need to create a component that redirects users to the login page provided by Control Center -- for when they click on the link or button. Here's an example of how you might do that:
+
+[source,java]
+----
+public class MainLayout extends AppLayout {
+
+    public MainLayout() {
+         /* <1> */
+        Button loginButton = new Button("Login", event -> { 
+            getUI().ifPresent(ui -> ui.getPage().setLocation("/oauth2/authorization/control-center"));
+        });
+
+         /* <2> */
+        Anchor loginLink = new Anchor("/oauth2/authorization/control-center", "Login");
+        loginLink.setRouterIgnore(true);
+
+        addToNavbar(loginButton, loginLink);
+    }
+}
+----
+
+<1> This part creates a login button.
+<2> This creates a login link. You may not want to do both a button and a link, though.
+
+
+== Adding Logout
+
+To add a logout link or button to a Vaadin application, you'll need to create a component that triggers the logout process. Here's an example of how to create a button, only:
+
+[source,java]
+----
+public class MainLayout extends AppLayout {
+
+    public MainLayout(@Autowired AuthenticationContext authenticationContext) {
+
+        Button logoutButton = new Button("Logout", click -> authenticationContext.logout());
+
+        addToNavbar(logoutButton);
+    }
+}
+----
+
+
+== Deploy the Application
+
+Deploy the application as described in <<../application-deployment#,Deploying a Vaadin Application with Control Center>>. Be sure to activate the Identity Management feature.