content: // 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.cloudstack.ratelimit;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertTrue;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.when;
  
  import java.util.Collections;
  import java.util.concurrent.CountDownLatch;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  
  import javax.naming.ConfigurationException;
  
  import org.junit.Before;
  import org.junit.BeforeClass;
  import org.junit.Test;
  
  import org.apache.cloudstack.api.response.ApiLimitResponse;
  import org.apache.cloudstack.framework.config.dao.ConfigurationDao;
  
  import com.cloud.configuration.Config;
  import com.cloud.exception.RequestLimitException;
  import com.cloud.user.Account;
  import com.cloud.user.AccountService;
  import com.cloud.user.AccountVO;
  import com.cloud.user.User;
  import com.cloud.user.UserVO;
  
  public class ApiRateLimitTest {
  
      static ApiRateLimitServiceImpl s_limitService = new ApiRateLimitServiceImpl();
      static AccountService s_accountService = mock(AccountService.class);
      static ConfigurationDao s_configDao = mock(ConfigurationDao.class);
      private static long s_acctIdSeq = 5L;
      private static Account s_testAccount;
  
      @BeforeClass
  public static void setUp() throws ConfigurationException {
  
          when(s_configDao.getValue(Config.ApiLimitInterval.key())).thenReturn(null);
          when(s_configDao.getValue(Config.ApiLimitMax.key())).thenReturn(null);
          when(s_configDao.getValue(Config.ApiLimitCacheSize.key())).thenReturn(null);
          when(s_configDao.getValue(Config.ApiLimitEnabled.key())).thenReturn("true"); // enable api rate limiting
          s_limitService._configDao = s_configDao;
  
          s_limitService.configure("ApiRateLimitTest", Collections.<String, Object> emptyMap());
  
          s_limitService._accountService = s_accountService;
  
          // Standard responses
          AccountVO acct = new AccountVO(s_acctIdSeq);
          acct.setType(Account.Type.NORMAL);
          acct.setAccountName("demo");
          s_testAccount = acct;
  
          when(s_accountService.getAccount(5L)).thenReturn(s_testAccount);
          when(s_accountService.isRootAdmin(5L)).thenReturn(false);
      }
  
      @Before
      public void testSetUp() {
          // reset counter for each test
          s_limitService.resetApiLimit(null);
      }
  
      private User createFakeUser() {
          UserVO user = new UserVO();
          user.setAccountId(s_acctIdSeq);
          return user;
      }
  
      private boolean isUnderLimit(User key) {
          try {
              s_limitService.checkAccess(key, null);
              return true;
          } catch (RequestLimitException ex) {
              return false;
          }
      }
  
      @Test
      public void sequentialApiAccess() {
          int allowedRequests = 1;
          s_limitService.setMaxAllowed(allowedRequests);
          s_limitService.setTimeToLive(1);
  
          User key = createFakeUser();
          assertTrue("Allow for the first request", isUnderLimit(key));
  
          assertFalse("Second request should be blocked, since we assume that the two api " + " accesses take less than a second to perform", isUnderLimit(key));
      }
  
      @Test
      public void canDoReasonableNumberOfApiAccessPerSecond() throws Exception {
          int allowedRequests = 200;
          s_limitService.setMaxAllowed(allowedRequests);
          s_limitService.setTimeToLive(5);
          long startTime = System.nanoTime();
  
          User key = createFakeUser();
  
          for (int i = 0; i < allowedRequests; i++) {
              assertTrue(String.format("We should allow %d requests per second, but failed at request %d.", allowedRequests, i), isUnderLimit(key));
          }
          // we cannot really say more about this test
          boolean underLimit =  isUnderLimit(key);
          long endTime = System.nanoTime();
          System.out.println("time elapsed " + (endTime - startTime)/1000/1000 + " ms");
          int issued = s_limitService.getIssued(key.getAccountId());
          int timeToLive = s_limitService.getTimeToLive();
  
          // this assertion is really invalid as we don´t know if we exceeded the time to live for the amount of api calls (for sure)
          // so only fail if timeToLive is not exeeded and we didn´t get the requested number of calls
          assertFalse(String.format("We should block >%d requests per %d seconds (managed %d, time elapsed %d ns)",
                  s_limitService.getMaxAllowed(), timeToLive, issued, endTime - startTime), ((endTime - startTime)/1000000000 < timeToLive) && underLimit);
      }
  
      @Test
      public void multipleClientsCanAccessWithoutBlocking() throws Exception {
          int allowedRequests = 200;
          s_limitService.setMaxAllowed(allowedRequests);
          s_limitService.setTimeToLive(1);
  
          final User key = createFakeUser();
  
          int clientCount = allowedRequests;
          Runnable[] clients = new Runnable[clientCount];
          final boolean[] isUsable = new boolean[clientCount];
  
          final CountDownLatch startGate = new CountDownLatch(1);
  
          final CountDownLatch endGate = new CountDownLatch(clientCount);
  
          for (int i = 0; i < isUsable.length; ++i) {
              final int j = i;
              clients[j] = new Runnable() {
  
                  /**
                   * {@inheritDoc}
                   */
                  @Override
                  public void run() {
                      try {
                          startGate.await();
  
                          isUsable[j] = isUnderLimit(key);
  
                      } catch (InterruptedException e) {
                          e.printStackTrace();
                      } finally {
                          endGate.countDown();
                      }
                  }
              };
          }
  
          ExecutorService executor = Executors.newFixedThreadPool(clientCount);
  
          for (Runnable runnable : clients) {
              executor.execute(runnable);
          }
  
          startGate.countDown();
  
          endGate.await();
  
          for (boolean b : isUsable) {
              assertTrue("Concurrent client request should be allowed within limit", b);
          }
      }
  
      @Test
      public void expiryOfCounterIsSupported() throws Exception {
          int allowedRequests = 1;
          s_limitService.setMaxAllowed(allowedRequests);
          s_limitService.setTimeToLive(1);
  
          User key = createFakeUser();
  
          assertTrue("The first request should be allowed", isUnderLimit(key));
  
          // Allow the token to expire
          Thread.sleep(1020);
  
          assertTrue("Another request after interval should be allowed as well", isUnderLimit(key));
      }
  
      @Test
      public void verifyResetCounters() throws Exception {
          int allowedRequests = 1;
          s_limitService.setMaxAllowed(allowedRequests);
          s_limitService.setTimeToLive(1);
  
          User key = createFakeUser();
  
          assertTrue("The first request should be allowed", isUnderLimit(key));
  
          assertFalse("Another request should be blocked", isUnderLimit(key));
  
          s_limitService.resetApiLimit(key.getAccountId());
  
          assertTrue("Another request should be allowed after reset counter", isUnderLimit(key));
      }
  
      @Test
      public void verifySearchCounter() throws Exception {
          int allowedRequests = 10;
          s_limitService.setMaxAllowed(allowedRequests);
          s_limitService.setTimeToLive(1);
  
          User key = createFakeUser();
  
          for (int i = 0; i < 5; i++) {
              assertTrue("Issued 5 requests", isUnderLimit(key));
          }
  
          ApiLimitResponse response = s_limitService.searchApiLimit(s_testAccount);
          assertEquals("apiIssued is incorrect", 5, response.getApiIssued());
          assertEquals("apiAllowed is incorrect", 5, response.getApiAllowed());
          // using <= to account for inaccurate System.currentTimeMillis() clock in Windows environment
          assertTrue("expiredAfter is incorrect", response.getExpireAfter() <= 1000);
  
      }
  
      @Test
      public void disableApiLimit() throws Exception {
          try {
              int allowedRequests = 200;
              s_limitService.setMaxAllowed(allowedRequests);
              s_limitService.setTimeToLive(1);
              s_limitService.setEnabled(false);
  
              User key = createFakeUser();
  
              for (int i = 0; i < allowedRequests + 1; i++) {
                  assertTrue("We should allow more than " + allowedRequests + " requests per second when api throttling is disabled.", isUnderLimit(key));
              }
          } finally {
              s_limitService.setEnabled(true); // enable api throttling to avoid
                                              // impacting other testcases
          }
  
      }
  
  }
  