content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.fuse.auth;
  
  import alluxio.AlluxioURI;
  import alluxio.client.file.FileSystem;
  import alluxio.conf.AlluxioConfiguration;
  import alluxio.conf.PropertyKey;
  import alluxio.exception.AlluxioException;
  import alluxio.exception.runtime.AlluxioRuntimeException;
  import alluxio.exception.runtime.InternalRuntimeException;
  import alluxio.fuse.AlluxioFuseUtils;
  import alluxio.grpc.SetAttributePOptions;
  import alluxio.jnifuse.FuseFileSystem;
  
  import com.google.common.base.Preconditions;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.util.Optional;
  
  /**
   * A Fuse authentication policy supports user-defined user and group.
   */
  public class CustomAuthPolicy extends LaunchUserGroupAuthPolicy {
    private static final Logger LOG =
        LoggerFactory.getLogger(CustomAuthPolicy.class);
    private final long mUid;
    private final long mGid;
    private final SetAttributePOptions mSetAttributeOptions;
  
    /**
     * Creates a new custom auth policy.
     *
     * @param fileSystem file system
     * @param conf the Alluxio configuration
     * @param fuseFileSystem fuse file system
     * @return custom auth policy
     */
    public static CustomAuthPolicy create(FileSystem fileSystem,
        AlluxioConfiguration conf, Optional<FuseFileSystem> fuseFileSystem) {
      String className = CustomAuthPolicy.class.getName();
      String owner = conf.getString(PropertyKey.FUSE_AUTH_POLICY_CUSTOM_USER);
      String group = conf.getString(PropertyKey.FUSE_AUTH_POLICY_CUSTOM_GROUP);
      Preconditions.checkArgument(!owner.isEmpty(),
          String.format("%s should not be null or empty when using %s",
              PropertyKey.FUSE_AUTH_POLICY_CUSTOM_USER.getName(), className));
      Preconditions.checkArgument(!group.isEmpty(),
          String.format("%s should not be null or empty when using %s",
              PropertyKey.FUSE_AUTH_POLICY_CUSTOM_GROUP.getName(), className));
      Optional<Long> uid = AlluxioFuseUtils.getUid(owner);
      Optional<Long> gid = AlluxioFuseUtils.getGidFromGroupName(group);
      if (!uid.isPresent()) {
        throw new InternalRuntimeException(String
            .format("Cannot create %s with invalid owner %s: failed to get uid", className, owner));
      }
      if (!gid.isPresent()) {
        throw new InternalRuntimeException(String
            .format("Cannot create %s with invalid group %s: failed to get gid", className, group));
      }
      SetAttributePOptions setAttributeOptions = SetAttributePOptions.newBuilder()
          .setOwner(owner).setGroup(group).build();
      LOG.info("Creating {} with owner [id {}, name {}] and group [id {}, name {}]",
          className, owner, uid, group, gid);
      return new CustomAuthPolicy(fileSystem, fuseFileSystem,
          uid.get(), gid.get(), setAttributeOptions);
    }
  
    /**
     * @param fileSystem     the Alluxio file system
     * @param fuseFileSystem the FuseFileSystem
     */
    private CustomAuthPolicy(FileSystem fileSystem, Optional<FuseFileSystem> fuseFileSystem,
        long uid, long gid, SetAttributePOptions options) {
      super(fileSystem, fuseFileSystem);
      mUid = uid;
      mGid = gid;
      mSetAttributeOptions = options;
    }
  
    @Override
    public void setUserGroupIfNeeded(AlluxioURI uri) {
      try {
        mFileSystem.setAttribute(uri, mSetAttributeOptions);
      } catch (IOException | AlluxioException e) {
        throw AlluxioRuntimeException.from(e);
      }
    }
  
    @Override
    public void setUserGroup(AlluxioURI uri, long uid, long gid) {
      if (uid == mUid && gid == mGid) {
        setUserGroupIfNeeded(uri);
        return;
      }
      super.setUserGroup(uri, uid, gid);
    }
  
    @Override
    public Optional<Long> getUid() {
      return Optional.of(mUid);
    }
  
    @Override
    public Optional<Long> getGid() {
      return Optional.of(mGid);
    }
  }
  