Enable authentication via Keycloak.

Change-Id: I81a05d2e965394b13d7344f4f20475b4e468c761
diff --git a/src/main/java/eu/mulk/mulkcms2/cms/web/ExampleResource.java b/src/main/java/eu/mulk/mulkcms2/cms/web/ExampleResource.java
index fc504c8..76602c8 100644
--- a/src/main/java/eu/mulk/mulkcms2/cms/web/ExampleResource.java
+++ b/src/main/java/eu/mulk/mulkcms2/cms/web/ExampleResource.java
@@ -1,14 +1,31 @@
 package eu.mulk.mulkcms2.cms.web;
 
+import io.quarkus.security.Authenticated;
+import io.quarkus.security.identity.SecurityIdentity;
+import io.smallrye.jwt.auth.principal.JWTCallerPrincipal;
+import javax.inject.Inject;
 import javax.ws.rs.GET;
+import javax.ws.rs.Path;
 import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;
+import org.jboss.logging.Logger;
 
+@Path("/example")
 public class ExampleResource {
 
+  private static Logger log = Logger.getLogger(ExampleResource.class);
+
+  @Inject
+  SecurityIdentity identity;
+
   @GET
   @Produces({MediaType.TEXT_PLAIN})
+  @Authenticated
   public String hello() {
+    if (!identity.isAnonymous()) {
+      var jwtCallerPrincipal = (JWTCallerPrincipal) identity.getPrincipal();
+      log.infof("Logged in as user: %s", jwtCallerPrincipal.getName());
+    }
     return "hello!";
   }
 }
diff --git a/src/main/resources/application.properties b/src/main/resources/application.properties
index 5173cbe..4ba1cb1 100644
--- a/src/main/resources/application.properties
+++ b/src/main/resources/application.properties
@@ -10,3 +10,7 @@
 %dev.quarkus.datasource.url = jdbc:postgresql://localhost:5432/flep
 %dev.quarkus.datasource.username = mulk
 %dev.quarkus.datasource.password =
+
+quarkus.oidc.auth-server-url = https://login.benkard.de/auth/realms/master
+quarkus.oidc.client-id = mulkcms
+quarkus.oidc.application-type = web-app