Do not fail when querying user federation providers and log messages to indicate the problem

Closes #42276

Signed-off-by: Pedro Igor <pigor.craveiro@gmail.com>

federation/ldap/src/main/java/org/keycloak/storage/ldap/LDAPStorageProvider.java

@@ -35,6 +35,8 @@ import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import javax.naming.AuthenticationException;
+import javax.naming.CommunicationException;
+import javax.naming.NameNotFoundException;
 import javax.naming.NamingException;
 import javax.naming.directory.SearchControls;
 
@@ -1123,19 +1125,36 @@ public class LDAPStorageProvider implements UserStorageProvider,
             return Stream.iterate(ldapQuery,
                     query -> {
                         //the very 1st page - Pagination context might not yet be present
-                        if (query.getPaginationContext() == null) try {
+                        if (query.getPaginationContext() == null) {
-                            query.initPagination();
+                            try {
-                            //returning true for first iteration as the LDAP was not queried yet
+                                query.initPagination();
-                            return true;
+                                //returning true for first iteration as the LDAP was not queried yet
-                        } catch (NamingException e) {
+                                return true;
-                            throw new ModelException("Querying of LDAP failed " + query, e);
+                            } catch (NameNotFoundException | CommunicationException e) {
+                                logger.errorf(e, "Failed to init LDAP query pagination %s", query);
+                                return false;
+                            } catch (NamingException e) {
+                                throw new ModelException("Querying of LDAP failed " + query, e);
+                            }
                         }
                         return query.getPaginationContext().hasNextPage();
                     },
                     query -> query
             ).flatMap(query -> {
                         query.setLimit(limit);
-                        List<LDAPObject> ldapObjects = query.getResultList();
+                        List<LDAPObject> ldapObjects;
+
+                        try {
+                            ldapObjects = query.getResultList();
+                        } catch (ModelException mde) {
+                            if (mde.isCausedBy(NameNotFoundException.class, CommunicationException.class)) {
+                                logger.errorf(mde, "Failed to query LDAP %s", query);
+                                return Stream.empty();
+                            } else {
+                                throw mde;
+                            }
+                        }
+
                         if (ldapObjects.isEmpty()) {
                             return Stream.empty();
                         }

model/storage-private/src/main/java/org/keycloak/storage/UserStorageManager.java

@@ -163,13 +163,19 @@ public class UserStorageManager extends AbstractStorageManager<UserStorageProvid
             return user;
         }
 
-        UserModel validated = validator.validate(realm, user);
+        try {
+            UserModel validated = validator.validate(realm, user);
 
-        if (validated == null) {
+            if (validated == null) {
-            return deleteFederatedUser(realm, user);
+                return deleteFederatedUser(realm, user);
+            }
+
+            return validated;
+        } catch (Exception e) {
+            logger.warnf(e, "User storage provider %s failed during federated user validation", model.getName());
         }
 
-        return validated;
+        return null;
     }
 
     private ReadOnlyUserModelDelegate deleteFederatedUser(RealmModel realm, UserModel user) {

server-spi/src/main/java/org/keycloak/models/ModelException.java

@@ -17,6 +17,8 @@
 
 package org.keycloak.models;
 
+import java.util.List;
+
 /**
  * @author <a href="mailto:sthorger@redhat.com">Stian Thorgersen</a>
  */
@@ -47,4 +49,23 @@ public class ModelException extends RuntimeException {
     public void setParameters(Object[] parameters) {
         this.parameters = parameters;
     }
+
+    @SafeVarargs
+    public final boolean isCausedBy(Class<? extends Exception>... type) {
+        int limit = 3;
+        List<Class<? extends Exception>> types = List.of(type);
+        Throwable cause = getCause();
+
+        while (cause != null) {
+            if (limit-- == 0) {
+                break;
+            }
+            if (types.contains(cause.getClass())) {
+                return true;
+            }
+            cause = cause.getCause();
+        }
+
+        return false;
+    }
 }