org.opencastproject.userdirectory.brightspace.BrightspaceUserProviderInstance Maven / Gradle / Ivy

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/*
 * Licensed to The Apereo Foundation under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 *
 * The Apereo Foundation licenses this file to you under the Educational
 * Community 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://opensource.org/licenses/ecl2.txt
 *
 * 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.opencastproject.userdirectory.brightspace;

import org.opencastproject.security.api.CachingUserProviderMXBean;
import org.opencastproject.security.api.Group;
import org.opencastproject.security.api.JaxbOrganization;
import org.opencastproject.security.api.JaxbRole;
import org.opencastproject.security.api.JaxbUser;
import org.opencastproject.security.api.Organization;
import org.opencastproject.security.api.Role;
import org.opencastproject.security.api.Role.Target;
import org.opencastproject.security.api.RoleProvider;
import org.opencastproject.security.api.User;
import org.opencastproject.security.api.UserProvider;
import org.opencastproject.userdirectory.brightspace.client.BrightspaceClient;
import org.opencastproject.userdirectory.brightspace.client.BrightspaceClientException;
import org.opencastproject.userdirectory.brightspace.client.api.BrightspaceUser;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.util.concurrent.ExecutionError;
import com.google.common.util.concurrent.UncheckedExecutionException;

//import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.management.ManagementFactory;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;

import javax.management.InstanceNotFoundException;
import javax.management.MBeanServer;
import javax.management.ObjectName;

public class BrightspaceUserProviderInstance implements UserProvider, RoleProvider, CachingUserProviderMXBean {

  private static final Logger logger = LoggerFactory.getLogger(BrightspaceUserProviderInstance.class);

  private static final String LTI_LEARNER_ROLE = "Learner";
  private static final String LTI_INSTRUCTOR_ROLE = "Instructor";

  private String pid;
  private BrightspaceClient client;
  private Organization organization;
  private LoadingCache cache;
  private Object nullToken = new Object();
  private AtomicLong loadUserRequests;
  private AtomicLong brightspaceWebServiceRequests;
  private final Set instructorRoles;
  private final Set ignoredUsernames;

  /**
   * Constructs a Brighspace user provider with the needed settings
   *
   * @param pid             The PID of this service.
   * @param client          The Brightspace rest service client.
   * @param organization    The organisation.
   * @param cacheSize       The number of users to cache.
   * @param cacheExpiration The number of minutes to cache users.
   */
  public BrightspaceUserProviderInstance(
      String pid,
      BrightspaceClient client,
      Organization organization,
      int cacheSize,
      int cacheExpiration,
      Set instructorRoles,
      Set ignoredUsernames
  ) {

    this.pid = pid;
    this.client = client;
    this.organization = organization;
    this.instructorRoles = instructorRoles;
    this.ignoredUsernames = ignoredUsernames;

    logger.info("Creating new BrightspaceUserProviderInstance(pid={}, url={}, cacheSize={}, cacheExpiration={}, "
                  + "InstructorRoles={}, ignoredUserNames={})", pid, client.getURL(), cacheSize, cacheExpiration,
                  instructorRoles, ignoredUsernames);

    cache = CacheBuilder.newBuilder().maximumSize(cacheSize).expireAfterWrite(cacheExpiration, TimeUnit.MINUTES)
            .build(new CacheLoader() {
              @Override
              public Object load(String username) {
                User user = loadUserFromBrightspace(username);
                return user == null ? nullToken : user;
              }
            });

    this.registerMBean(pid);
  }

  @Override
  public float getCacheHitRatio() {
    if (loadUserRequests.get() == 0) {
      return 0;
    }
    return (float) (loadUserRequests.get() - brightspaceWebServiceRequests.get()) / loadUserRequests.get();
  }

  private void registerMBean(String pid) {
    this.loadUserRequests = new AtomicLong();
    this.brightspaceWebServiceRequests = new AtomicLong();

    try {
      ObjectName name = BrightspaceUserProviderFactory.getObjectName(pid);
      MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();

      try {
        mbs.unregisterMBean(name);
      } catch (InstanceNotFoundException ife) {
        logger.debug("{} was not registered", name);
      }

      mbs.registerMBean(this, name);
    } catch (Exception e) {
      logger.error("Unable to register {} as an mbean: {}", this, e);
    }

  }

  /**
   * {@inheritDoc}
   *
   * @see org.opencastproject.security.api.UserProvider#getName()
   */
  @Override
  public String getName() {
    return pid;
  }

  /**
   * {@inheritDoc}
   *
   * @see org.opencastproject.security.api.UserProvider#getUsers()
   */
  @Override
  public Iterator getUsers() {
    return Collections.emptyIterator();
  }

  /**
   * {@inheritDoc}
   *
   * @see org.opencastproject.security.api.UserProvider#loadUser(java.lang.String)
   */
  @Override
  public User loadUser(String userName) {
    this.loadUserRequests.incrementAndGet();
    logger.debug("getting user from cache");

    try {
      Object user = this.cache.getUnchecked(userName);
      if (user != this.nullToken) {
        logger.debug("Returning user {} from cache", userName);
        return (User) user;
      } else {
        logger.debug("Returning null user from cache");
        return null;
      }
    } catch (ExecutionError | UncheckedExecutionException ee) {
      logger.warn("Exception while loading user {}", userName, ee);
      return null;
    }
  }

  /**
   * {@inheritDoc}
   *
   * @see org.opencastproject.security.api.UserProvider#countUsers()
   */
  @Override
  public long countUsers() {
    return 0L;
  }

  /**
   * {@inheritDoc}
   *
   * @see org.opencastproject.security.api.UserProvider#getOrganization()
   */
  @Override
  public String getOrganization() {
    return this.organization.getId();
  }

  /**
   * {@inheritDoc}
   *
   * @see org.opencastproject.security.api.UserProvider#findUsers(java.lang.String, int, int)
   */
  @Override
  public Iterator findUsers(String query, int offset, int limit) {
    return Collections.emptyIterator();
  }

  @Override
  public void invalidate(String userName) {
    this.cache.invalidate(userName);
  }

  @Override
  public List getRolesForUser(String username) {
    User user = this.loadUser(username);
    if (user != null) {
      logger.debug("Returning cached role set for {}", username);
      return new ArrayList<>(user.getRoles());
    }
    logger.debug("Return empty role set for {} - not found in Brightspace", username);
    return Collections.emptyList();
  }

  @Override
  public Iterator findRoles(String query, Target target, int offset, int limit) {
    return Collections.emptyIterator();
  }

  private User loadUserFromBrightspace(String username) {
    if (this.cache == null) {
      throw new IllegalStateException("The Brightspace user detail service has not yet been configured");
    } else if (ignoredUsernames.stream().anyMatch(u -> u.equals(username))) {
      logger.debug("We don't answer for: " + username);
      return null;
    } else {

      logger.debug("In loadUserFromBrightspace, currently processing user: {}", username);
      JaxbOrganization jaxbOrganization = JaxbOrganization.fromOrganization(organization);

      this.brightspaceWebServiceRequests.incrementAndGet();
      Thread currentThread = Thread.currentThread();
      ClassLoader originalClassloader = currentThread.getContextClassLoader();
      BrightspaceUser brightspaceUser;

      try {
        brightspaceUser = this.client.findUser(username);

        if (brightspaceUser != null) {
          logger.info("Retrieved user {}", brightspaceUser.getUserId());
          String brightspaceUserId = brightspaceUser.getUserId();

          List roleList = client.getRolesFromBrightspace(brightspaceUserId, instructorRoles);
          logger.debug("Brightspace user {} with id {} with roles: {}", username, brightspaceUserId, roleList);

          Set roles = new HashSet<>();
          boolean isInstructor = false;
          for (String roleStr: roleList) {
            roles.add(new JaxbRole(roleStr, jaxbOrganization, "Brightspace external role", Role.Type.EXTERNAL));
            if (roleStr.endsWith(LTI_INSTRUCTOR_ROLE)) {
              isInstructor = true;
            }
          }
          roles.add(new JaxbRole(Group.ROLE_PREFIX + "BRIGHTSPACE", jaxbOrganization, "Brightspace User",
                  Role.Type.EXTERNAL_GROUP));
          if (isInstructor) {
            roles.add(new JaxbRole(Group.ROLE_PREFIX + "BRIGHTSPACE_INSTRUCTOR", jaxbOrganization,
                      "Brightspace Instructor", Role.Type.EXTERNAL_GROUP));
          }
          logger.debug("Returning JaxbRoles: {}", roles);

          User user =  new JaxbUser(username, null, brightspaceUser.getDisplayName(),
                  brightspaceUser.getExternalEmail(), this.getName(), jaxbOrganization, roles);
          cache.put(username, user);
          logger.debug("Returning user {}", user);
          return user;
        } else {
          cache.put(username, nullToken);
          logger.debug("User {} not found in Brightspace system", username);
          return null;
        }
      } catch (BrightspaceClientException e) {
        logger.error("A Brightspace API error ( {} ) occurred, user {} could not be retrieved", e, username);
        return null;
      } finally {
        currentThread.setContextClassLoader(originalClassloader);
      }
    }
  }
}