AMBARI-18520: Ambari usernames should not be converted to lowercase before storing in the DB.

ambari-server/src/main/java/org/apache/ambari/server/api/services/UserService.java

@@ -172,6 +172,6 @@ public class UserService extends BaseService {
    */
   private ResourceInstance createUserResource(String userName) {
     return createResource(Resource.Type.User,
-        Collections.singletonMap(Resource.Type.User, StringUtils.lowerCase(userName)));
+        Collections.singletonMap(Resource.Type.User, userName));
   }
 }

ambari-server/src/main/java/org/apache/ambari/server/controller/internal/UserResourceProvider.java

@@ -21,6 +21,7 @@ import org.apache.ambari.server.AmbariException;
 import org.apache.ambari.server.controller.AmbariManagementController;
 import org.apache.ambari.server.controller.UserRequest;
 import org.apache.ambari.server.controller.UserResponse;
+import org.apache.ambari.server.controller.predicate.EqualsPredicate;
 import org.apache.ambari.server.controller.spi.*;
 import org.apache.ambari.server.controller.utilities.PropertyHelper;
 import org.apache.ambari.server.security.authorization.AuthorizationException;
@@ -35,7 +36,7 @@ import java.util.Set;
 /**
  * Resource provider for user resources.
  */
-public class UserResourceProvider extends AbstractControllerResourceProvider {
+public class UserResourceProvider extends AbstractControllerResourceProvider implements ResourcePredicateEvaluator {
 
   // ----- Property ID constants ---------------------------------------------
 
@@ -188,6 +189,28 @@ public class UserResourceProvider extends AbstractControllerResourceProvider {
     return getRequestStatus(null);
   }
 
+  /**
+   * ResourcePredicateEvaluator implementation. If property type is User/user_name,
+   * we do a case insensitive comparison so that we can return the retrieved
+   * username when it differs only in case with respect to the requested username.
+   *
+   * @param predicate  the predicate
+   * @param resource   the resource
+   *
+     * @return
+     */
+  @Override
+  public boolean evaluate(Predicate predicate, Resource resource) {
+    if (predicate instanceof EqualsPredicate) {
+      EqualsPredicate equalsPredicate = (EqualsPredicate)predicate;
+      String propertyId = equalsPredicate.getPropertyId();
+      if (propertyId.equals(USER_USERNAME_PROPERTY_ID)) {
+        return equalsPredicate.evaluateIgnoreCase(resource);
+      }
+    }
+    return predicate.evaluate(resource);
+  }
+
   @Override
   protected Set<String> getPKPropertyIds() {
     return pkPropertyIds;

ambari-server/src/main/java/org/apache/ambari/server/controller/predicate/ComparisonPredicate.java

@@ -76,7 +76,15 @@ public abstract class ComparisonPredicate<T> extends PropertyPredicate implement
     visitor.acceptComparisonPredicate(this);
   }
 
+  protected int compareValueToIgnoreCase(Object propertyValue) throws ClassCastException{
+    return compareValueTo(propertyValue, true); // case insensitive
+  }
+
   protected int compareValueTo(Object propertyValue) throws ClassCastException{
+    return compareValueTo(propertyValue, false); // case sensitive
+  }
+
+  private int compareValueTo(Object propertyValue, boolean ignoreCase) throws ClassCastException {
     if (doubleValue != null) {
       if (propertyValue instanceof Number) {
         return doubleValue.compareTo(((Number) propertyValue).doubleValue());
@@ -88,8 +96,14 @@ public abstract class ComparisonPredicate<T> extends PropertyPredicate implement
         }
       }
     }
+
     if (stringValue != null) {
-      return stringValue.compareTo(propertyValue.toString());
+      if (ignoreCase) {
+        return stringValue.compareToIgnoreCase(propertyValue.toString());
+      }
+      else {
+        return stringValue.compareTo(propertyValue.toString());
+      }
     }
 
     return getValue().compareTo((T) propertyValue);

ambari-server/src/main/java/org/apache/ambari/server/controller/predicate/EqualsPredicate.java

@@ -39,6 +39,21 @@ public class EqualsPredicate<T> extends ComparisonPredicate<T> {
         propertyValue != null && compareValueTo(propertyValue) == 0;
   }
 
+  /**
+   * Case insensitive equality support for string types
+   *
+   * @param resource
+   * @return
+     */
+  public boolean evaluateIgnoreCase(Resource resource) {
+    Object propertyValue  = resource.getPropertyValue(getPropertyId());
+    Object predicateValue = getValue();
+
+    return predicateValue == null ?
+            propertyValue == null :
+            propertyValue != null && compareValueToIgnoreCase(propertyValue) == 0;
+  }
+
   @Override
   public String getOperator() {
     return "=";

ambari-server/src/main/java/org/apache/ambari/server/security/authorization/User.java

@@ -46,7 +46,7 @@ public class User {
 
   public User(UserEntity userEntity) {
     userId = userEntity.getUserId();
-    userName = StringUtils.lowerCase(userEntity.getUserName()); // normalize to lower case
+    userName = userEntity.getUserName();
     createTime = userEntity.getCreateTime();
     userType = userEntity.getUserType();
     ldapUser = userEntity.getLdapUser();

ambari-server/src/main/java/org/apache/ambari/server/security/authorization/Users.java

@@ -282,11 +282,9 @@ public class Users {
       throw new AmbariException("UserType not specified.");
     }
 
-    // store user name in lower case
-    userName = StringUtils.lowerCase(userName);
-
-    if (getUser(userName, userType) != null) {
-      throw new AmbariException("User " + userName + " already exists");
+    User existingUser = getUser(userName, userType);
+    if (existingUser != null) {
+      throw new AmbariException("User " + existingUser.getUserName() + " already exists");
     }
 
     PrincipalTypeEntity principalTypeEntity = principalTypeDAO.findById(PrincipalTypeEntity.USER_PRINCIPAL_TYPE);

ambari-server/src/test/java/org/apache/ambari/server/api/services/UserServiceTest.java

@@ -1,71 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.ambari.server.api.services;
-
-import javax.ws.rs.core.HttpHeaders;
-import javax.ws.rs.core.MultivaluedMap;
-import javax.ws.rs.core.Response;
-import javax.ws.rs.core.UriInfo;
-
-import org.apache.ambari.server.api.resources.ResourceInstance;
-import org.apache.ambari.server.controller.spi.Resource;
-import org.apache.ambari.server.orm.entities.UserEntity;
-import org.junit.Test;
-
-import static org.junit.Assert.assertEquals;
-
-/**
- * Unit tests for UserService.
- */
-public class UserServiceTest {
-
-  @Test
-  public void testCreateResourcesWithUppercaseUsername() {
-    // GIVEN
-    UserService userService = new TestUserService();
-    // WHEN
-    Response response = userService.getUser(null, null, null, "MyUser");
-    // THEN
-    assertEquals("myuser", ((UserEntity) response.getEntity()).getUserName());
-  }
-
-  class TestUserService extends UserService {
-    @Override
-    protected Response handleRequest(HttpHeaders headers, String body, UriInfo uriInfo,
-                                     Request.Type requestType, final ResourceInstance resource) {
-      return new Response() {
-        @Override
-        public Object getEntity() {
-          UserEntity entity = new UserEntity();
-          entity.setUserName(resource.getKeyValueMap().get(Resource.Type.User));
-          return entity;
-        }
-
-        @Override
-        public int getStatus() {
-          return 0;
-        }
-
-        @Override
-        public MultivaluedMap<String, Object> getMetadata() {
-          return null;
-        }
-      };
-    }
-  }
-}

ambari-server/src/test/java/org/apache/ambari/server/security/SecurityHelperImplTest.java

@@ -44,13 +44,13 @@ public class SecurityHelperImplTest {
     SecurityContext ctx = SecurityContextHolder.getContext();
     UserEntity userEntity = new UserEntity();
     userEntity.setPrincipal(new PrincipalEntity());
-    userEntity.setUserName("username"); // with user entity, always use lower case
+    userEntity.setUserName("userName");
     userEntity.setUserId(1);
     User user = new User(userEntity);
     Authentication auth = new AmbariUserAuthentication(null, user, null);
     ctx.setAuthentication(auth);
 
-    Assert.assertEquals("username", SecurityHelperImpl.getInstance().getCurrentUserName());
+    Assert.assertEquals("userName", SecurityHelperImpl.getInstance().getCurrentUserName());
   }
 
   @Test

ambari-server/src/test/java/org/apache/ambari/server/security/authorization/AmbariUserAuthenticationFilterTest.java

@@ -52,7 +52,7 @@ import static org.junit.Assert.assertNull;
 public class AmbariUserAuthenticationFilterTest {
   private static final String TEST_INTERNAL_TOKEN = "test token";
   private static final String TEST_USER_ID_HEADER = "1";
-  private static final String TEST_USER_NAME = "username"; // use lower case with user entity
+  private static final String TEST_USER_NAME = "userName";
   private static final int TEST_USER_ID = 1;
 
   @Before

ambari-server/src/test/java/org/apache/ambari/server/upgrade/UpgradeCatalog240Test.java

@@ -2470,17 +2470,17 @@ public class UpgradeCatalog240Test {
     final Users users = createMock(Users.class);
 
     RequestScheduleEntity requestScheduleEntity = new RequestScheduleEntity();
-    requestScheduleEntity.setCreateUser("createduser"); // use lower case user name with request schedule entity
+    requestScheduleEntity.setCreateUser("createdUser");
     requestScheduleEntity.setClusterId(1L);
 
     expect(requestScheduleDAO.findAll()).andReturn(Collections.singletonList(requestScheduleEntity)).once();
 
     UserEntity userEntity = new UserEntity();
-    userEntity.setUserName("createduser"); // use lower case user name with user entity
+    userEntity.setUserName("createdUser");
     userEntity.setUserId(1);
     userEntity.setPrincipal(new PrincipalEntity());
     User user = new User(userEntity);
-    expect(users.getUserIfUnique("createduser")).andReturn(user).once();
+    expect(users.getUserIfUnique("createdUser")).andReturn(user).once();
 
     expect(requestScheduleDAO.merge(requestScheduleEntity)).andReturn(requestScheduleEntity).once();