restful: provide functionality to remove or add labels of a file

Motivation

Allow any dCache service to modify and remove labels
attributes.

Modification:

Add set-label and rm-label fucntions to restful Api.
Additional Message subclasses has been added  to allow dCache services to
request that PnfsManager updates (remove) a file's label.
Implement support for these  new message in PnfsManager.

The following curl command will be used to modify file's label.

Result:

 user- or admin can mdify  remove file labels.

Target: master
Require-book: yes
Require-notes: yes
Patch: https://rb.dcache.org/r/13079/
Acked-by: Lea Morschel, Tigran Mkrtchyan
Commited

modules/dcache-chimera/src/main/java/org/dcache/chimera/namespace/ChimeraNameSpaceProvider.java

@@ -1133,6 +1133,8 @@ public FileAttributes setFileAttributes(Subject subject, PnfsId pnfsId,
                         break;
                     case XATTR:
                         break;
+                    case LABELS:
+                        break;
                     default:
                         throw new UnsupportedOperationException("Attribute " + attribute + " not supported yet.");
                 }
@@ -1794,4 +1796,42 @@ public void removeExtendedAttribute(Subject subject, FsPath path, String name)
                     + Exceptions.messageOrClassName(e), e);
         }
     }
+
+    /**@param subject The user making the request.
+     * Remove a label from a file.
+     *
+     * @param path The file from which the label  is deleted.
+     * @param label The name of the label to remove.
+     * @throws FileNotFoundCacheException     if the path does not exist.
+     * @throws PermissionDeniedCacheException if the user is not allowed to
+     * remove the label.
+     * @throws CacheException a generic failure in removing the labe.
+     **/
+    public void removeLabel(Subject subject, FsPath path, String label) throws CacheException {
+        try {
+            ExtendedInode target = pathToInode(subject, path.toString());
+
+            if (!Subjects.isRoot(subject)) {
+
+                FileAttributes attributes = getFileAttributesForPermissionHandler(target);
+
+                if (target.isDirectory()) {
+
+                    throw new NotFileCacheException("Directory object cannot have a label.");
+
+                } else {
+                    if (_permissionHandler.canWriteFile(subject, attributes) != ACCESS_ALLOWED) {
+                        throw new PermissionDeniedCacheException("Access denied");
+                    }
+                }            }
+            _fs.removeLabel(target, label);
+
+        } catch (FileNotFoundChimeraFsException e) {
+            throw new FileNotFoundCacheException("No such file " + path);
+        } catch (ChimeraFsException e) {
+            throw new CacheException("Failed to remove the label: "
+                    + Exceptions.messageOrClassName(e), e);
+        }
+
+    }
 }

modules/dcache-frontend/src/main/java/org/dcache/restful/resources/namespace/FileResources.java

@@ -307,6 +307,15 @@ public Response cmrResources(@ApiParam(value="Path of file or directory to be mo
                                              + "corresponding JSON Object's "
                                              + "value is this attribute's value."
                                              + "\n"
+                                             + "If action is 'set-label' then "
+                                             + "a label is added to the"
+                                             + "given file object."
+                                             + "'label' item value is a String."
+                                             + "\n"
+                                             + "If action is 'rm-label' then the corresponding"
+                                             + "label of a file is removed."
+                                             + "The  'label' value is either a string."
+                                             + "\n"
                                              + "If action is 'chgrp' then the "
                                              + "command requests the change of "
                                              + "group-owner of the target file "
@@ -356,6 +365,18 @@ public Response cmrResources(@ApiParam(value="Path of file or directory to be mo
                                                          + "        \"attr-2\"\n"
                                                          + "    ]\n"
                                                          + "}"),
+
+                                             @ExampleProperty(mediaType = "SET-LABEL",
+                                                         value = "{\n"
+                                                         + "    \"action\" : \"set-label\",\n"
+                                                         + "    \"label\" : : \"label\",\n"
+                                                         + "}"),
+
+                                             @ExampleProperty(mediaType = "RM-LABEL",
+                                                         value = "{\n"
+                                                         + "    \"action\" : \"rm-label\",\n"
+                                                         + "    \"label\" :  \"label\",\n"
+                                                         + "}"),
                                              @ExampleProperty(mediaType = "CHGRP",
                                                      value = "{\n"
                                                          + "    \"action\" : \"chgrp\",\n"
@@ -421,6 +442,14 @@ public Response cmrResources(@ApiParam(value="Path of file or directory to be mo
                     }
                     pnfsHandler.writeExtendedAttribute(path, attributes, xattrSetMode);
                     break;
+                case "set-label":
+                    String label = reqPayload.getString("label");
+                    pnfsHandler.setFileAttributes(path,FileAttributes.ofLabel(label)) ;
+                    break;
+                case "rm-label":
+                    String labelsArgument = reqPayload.getString("label");
+                    pnfsHandler.removeLabel(path, labelsArgument);
+                    break;
                 case "chgrp":
                     int gid = reqPayload.getInt("gid");
                     pnfsHandler.setFileAttributes(path, FileAttributes.ofGid(gid));

modules/dcache-vehicles/src/main/java/diskCacheV111/vehicles/PnfsRemoveLabelsMessage.java

@@ -0,0 +1,58 @@
+/* dCache - http://www.dcache.org/
+ *
+ * Copyright (C) 2021 Deutsches Elektronen-Synchrotron
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package diskCacheV111.vehicles;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import diskCacheV111.util.PnfsId;
+
+/**
+ * Remove a label of  a file object.
+ */
+public class PnfsRemoveLabelsMessage extends PnfsMessage
+{
+    private static final long serialVersionUID = -3390360138874265448L;
+
+    private final Set<String> _labels = new HashSet<>();
+
+    public PnfsRemoveLabelsMessage(PnfsId id)
+    {
+        super(id);
+    }
+
+    public PnfsRemoveLabelsMessage(String path)
+    {
+        setPnfsPath(path);
+    }
+
+    public void addLabel(String label)
+    {
+        _labels.add(label);
+    }
+
+    public Set<String> getLabels()
+    {
+        return _labels;
+    }
+
+    public void clearLabel()
+    {
+        _labels.clear();
+    }
+}

modules/dcache-vehicles/src/main/java/org/dcache/vehicles/FileAttributes.java

@@ -883,6 +883,10 @@ public static FileAttributes ofLocations(Collection<String> pools)
         return of().locations(pools).build();
     }
 
+    public static FileAttributes ofLabel(String label) {
+        return of().label(label).build();
+    }
+
     public static FileAttributes ofHsm(String hsm)
     {
         return of().hsm(hsm).build();
@@ -1087,5 +1091,13 @@ public Builder xattrs(Map<String, String> xattrs) {
             getXattrs().putAll(xattrs);
             return this;
         }
+
+        public Builder label(String label) {
+            if (!isDefined(LABELS)) {
+                setLabels(new HashSet());
+            }
+            getLabels().add(label);
+            return this;
+        }
     }
 }

modules/dcache/src/main/java/diskCacheV111/namespace/ForwardingNameSpaceProvider.java

@@ -32,6 +32,7 @@
 import diskCacheV111.util.PnfsId;
 import diskCacheV111.util.RetentionPolicy;
 
+
 import org.dcache.namespace.CreateOption;
 import org.dcache.namespace.FileAttribute;
 import org.dcache.namespace.FileType;
@@ -235,4 +236,10 @@ public void updateFsStat() throws CacheException {
         delegate().updateFsStat();
     }
 
+    @Override
+    public void removeLabel(Subject subject, FsPath path, String name) throws CacheException
+    {
+        delegate().removeLabel(subject, path, name);
+
+    }
 }

modules/dcache/src/main/java/diskCacheV111/namespace/NameSpaceProvider.java

@@ -424,4 +424,17 @@ void removeExtendedAttribute(Subject subject, FsPath path, String name)
      */
     void updateFsStat() throws CacheException;
 
+    /**
+     * Remove a label from a file.
+     * @param subject The user making the request.
+     * @param path The file from which the label is deleted.
+     * @param label The labelto remove.
+     * @throws FileNotFoundCacheException if the path does not exist.
+     * @throws PermissionDeniedCacheException if the user is not allowed to
+     * remove the label.
+     * @throws CacheException a generic failure in removing the attribute.
+     */
+    void removeLabel(Subject subject, FsPath path, String label)  throws  CacheException;
+
+
 }

modules/dcache/src/main/java/diskCacheV111/namespace/PnfsManagerV3.java

@@ -69,6 +69,7 @@
 import diskCacheV111.vehicles.PnfsReadExtendedAttributesMessage;
 import diskCacheV111.vehicles.PnfsRemoveExtendedAttributesMessage;
 import diskCacheV111.vehicles.PnfsRenameMessage;
+import diskCacheV111.vehicles.PnfsRemoveLabelsMessage;
 import diskCacheV111.vehicles.PnfsWriteExtendedAttributesMessage;
 import diskCacheV111.vehicles.PoolFileFlushedMessage;
 import diskCacheV111.vehicles.StorageInfo;
@@ -268,6 +269,7 @@ private void populateRequestMap()
         _gauges.addGauge(PnfsReadExtendedAttributesMessage.class);
         _gauges.addGauge(PnfsWriteExtendedAttributesMessage.class);
         _gauges.addGauge(PnfsRemoveExtendedAttributesMessage.class);
+        _gauges.addGauge(PnfsRemoveLabelsMessage.class);
     }
 
     public PnfsManagerV3()
@@ -2644,6 +2646,8 @@ private boolean processMessageTransactionally(CellMessage message, PnfsMessage p
             writeExtendedAttributes((PnfsWriteExtendedAttributesMessage) pnfsMessage);
         } else if (pnfsMessage instanceof PnfsRemoveExtendedAttributesMessage) {
             removeExtendedAttributes((PnfsRemoveExtendedAttributesMessage) pnfsMessage);
+        } else if (pnfsMessage instanceof PnfsRemoveLabelsMessage) {
+                removeLabel((PnfsRemoveLabelsMessage) pnfsMessage);
         } else {
             LOGGER.warn("Unexpected message class [{}] from source [{}]",
                       pnfsMessage.getClass(), message.getSourcePath());
@@ -3039,6 +3043,33 @@ private void removeExtendedAttributes(PnfsRemoveExtendedAttributesMessage messag
         }
     }
 
+    private void removeLabel(PnfsRemoveLabelsMessage message)
+    {
+        try {
+            if (message.getFsPath() == null) {
+                throw new CacheException("PNFS-ID based label removal is not supported");
+            }
+
+            populatePnfsId(message);
+
+            checkMask(message);
+            checkRestriction(message, UPDATE_METADATA);
+            FsPath path = message.getFsPath();
+
+            for (String name : message.getLabels()) {
+                _nameSpaceProvider.removeLabel(message.getSubject(),
+                        path, name);
+
+            }
+            message.clearLabel();
+            message.setSucceeded();
+
+        } catch (CacheException e) {
+            message.clearLabel();
+            message.setFailed(e.getRc(), e);
+        }
+
+    }
     private PnfsId populatePnfsId(PnfsMessage message)
         throws CacheException
     {

modules/dcache/src/main/java/diskCacheV111/util/PnfsHandler.java

@@ -28,6 +28,7 @@
 import diskCacheV111.vehicles.PnfsMessage;
 import diskCacheV111.vehicles.PnfsReadExtendedAttributesMessage;
 import diskCacheV111.vehicles.PnfsRemoveExtendedAttributesMessage;
+import diskCacheV111.vehicles.PnfsRemoveLabelsMessage;
 import diskCacheV111.vehicles.PnfsRenameMessage;
 import diskCacheV111.vehicles.PnfsWriteExtendedAttributesMessage;
 import diskCacheV111.vehicles.PnfsWriteExtendedAttributesMessage.Mode;
@@ -761,4 +762,24 @@ public void removeExtendedAttribute(FsPath path, Collection<String> names)
         names.forEach(message::addName);
         request(message);
     }
+
+    /**
+     * Remove a label attribute from a file.
+     * @param path The file from which the label  is deleted.
+     * @param label The name of the label to remove.
+     * @throws FileNotFoundCacheException if the path does not exist.
+     * @throws PermissionDeniedCacheException if the user is not allowed to
+     * remove the label.
+     * @throws CacheException if the label does not exist or the object is a directory.
+     * @throws CacheException a generic failure in removing the label.
+     */
+
+    public void removeLabel(FsPath path, String label) throws CacheException
+    {
+
+        PnfsRemoveLabelsMessage message =
+                new PnfsRemoveLabelsMessage(path.toString());
+        message.addLabel(label);
+        request(message);
+    }
 }

modules/dcache/src/main/java/org/dcache/auth/RemoteNameSpaceProvider.java

@@ -5,7 +5,6 @@
 import javax.security.auth.Subject;
 
 import java.util.Collection;
-import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 
@@ -26,6 +25,7 @@
 import diskCacheV111.vehicles.PnfsListExtendedAttributesMessage;
 import diskCacheV111.vehicles.PnfsReadExtendedAttributesMessage;
 import diskCacheV111.vehicles.PnfsRemoveExtendedAttributesMessage;
+import diskCacheV111.vehicles.PnfsRemoveLabelsMessage;
 import diskCacheV111.vehicles.PnfsWriteExtendedAttributesMessage;
 
 import org.dcache.auth.attributes.Restrictions;
@@ -315,4 +315,23 @@ public void removeExtendedAttribute(Subject subject, FsPath path, String name)
         message.setRestriction(Restrictions.none());
         _pnfs.request(message);
     }
+
+
+    /**
+     * Remove a label attribute from a file.
+     * @param subject The user making the request.
+     * @param path The file from which the label is deleted.
+     * @param label The name of the label to be remove.
+     * @throws CacheException a generic failure in removing the label.
+     */
+    public void removeLabel(Subject subject, FsPath path, String label) throws CacheException
+    {
+        PnfsRemoveLabelsMessage message =
+                new PnfsRemoveLabelsMessage(path.toString());
+        message.addLabel(label);
+        message.setSubject(subject);
+        message.setRestriction(Restrictions.none());
+        _pnfs.request(message);
+
+    }
 }