[GEODE-10611] Add configurable output directories for export data

geode-docs/tools_modules/gfsh/command-pages/export.html.md.erb

@@ -165,6 +165,22 @@ In this scenario, partitioned region data is exported simultaneously on all host
 | <span class="keyword parmname">&#8209;&#8209;dir</span>   | Directory to which the exported data is to be written. Required if &#8209;&#8209;parallel is true. Cannot be specified at the same time as &#8209;&#8209;file.|
 | <span class="keyword parmname">&#8209;&#8209;parallel</span>   | Export local data on each node to a directory on that machine. Available for partitioned regions only.  |
 
+**Export locations:**
+
+The snapshot is written by the member named in `--member`, on that member's host. A member writes
+exports into its own working directory (and sub-directories of it). To export somewhere else, such
+as a mounted backup location, set the `gemfire.export.data.dirs` system property on the member to
+the additional directories, separated by the platform's path separator:
+
+``` pre
+-Dgemfire.export.data.dirs=/mnt/backup/geode:/var/exports/geode
+```
+
+A path containing a `..` segment is not accepted, and a path that resolves outside the configured
+directories is rejected by the member.
+
+**Required permission:** `DATA:READ` on the exported region, plus `CLUSTER:WRITE`.
+
 **Example Commands:**
 
 ``` pre

geode-gfsh/src/distributedTest/java/org/apache/geode/management/internal/cli/commands/ExportDataCommandPermissionsDUnitTest.java

@@ -0,0 +1,227 @@
+/*
+ * 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.geode.management.internal.cli.commands;
+
+import static org.apache.geode.distributed.ConfigurationProperties.SECURITY_MANAGER;
+import static org.apache.geode.management.internal.cli.functions.ExportDataFunction.EXPORT_DATA_DIRS_PROPERTY;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.Serializable;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Properties;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.junit.rules.TemporaryFolder;
+
+import org.apache.geode.cache.RegionShortcut;
+import org.apache.geode.examples.SimpleSecurityManager;
+import org.apache.geode.internal.cache.InternalCache;
+import org.apache.geode.management.internal.security.ResourceConstants;
+import org.apache.geode.test.dunit.IgnoredException;
+import org.apache.geode.test.dunit.rules.ClusterStartupRule;
+import org.apache.geode.test.dunit.rules.MemberVM;
+import org.apache.geode.test.junit.categories.SecurityTest;
+import org.apache.geode.test.junit.rules.GfshCommandRule;
+
+/**
+ * Tests which principals may run {@code export data} in a secured cluster.
+ *
+ * <p>
+ * {@link SimpleSecurityManager} authorizes a user for exactly those permissions whose string form
+ * starts with the user name, and treats a comma separated user name as a set of roles. So
+ * "dataRead" holds DATA:READ alone, while "dataRead,clusterWrite" is the operator {@code
+ * export data} requires.
+ */
+@Category(SecurityTest.class)
+public class ExportDataCommandPermissionsDUnitTest implements Serializable {
+
+  private static final String REGION_NAME = "testRegion";
+  private static final String READ_ONLY_USER = "dataRead";
+  private static final String EXPORT_OPERATOR = "dataRead,clusterWrite";
+
+  @ClassRule
+  public static ClusterStartupRule cluster = new ClusterStartupRule();
+
+  @Rule
+  public GfshCommandRule gfsh = new GfshCommandRule();
+
+  @Rule
+  public TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+  private static MemberVM locator;
+  private static MemberVM server;
+
+  /** The directory the server has been configured to permit exports into. */
+  private Path permittedDir;
+
+  /** Any other location on the server host. */
+  private Path otherDir;
+
+  @BeforeClass
+  public static void beforeClass() {
+    Properties locatorProps = new Properties();
+    locatorProps.setProperty(SECURITY_MANAGER, SimpleSecurityManager.class.getName());
+    locator = cluster.startLocatorVM(0, locatorProps);
+
+    Properties serverProps = new Properties();
+    serverProps.setProperty(ResourceConstants.USER_NAME, "clusterManage");
+    serverProps.setProperty(ResourceConstants.PASSWORD, "clusterManage");
+    server = cluster.startServerVM(1, serverProps, locator.getPort());
+
+    server.invoke(() -> {
+      InternalCache cache = ClusterStartupRule.getCache();
+      assertThat(cache).isNotNull();
+      cache.createRegionFactory(RegionShortcut.REPLICATE).create(REGION_NAME).put("key", "value");
+    });
+  }
+
+  @Before
+  public void configurePermittedExportDirectory() throws Exception {
+    // Refusing an export is logged at error level on the member; that is the expected outcome of
+    // most of these tests, not a symptom of one going wrong.
+    IgnoredException.addIgnoredException("Cannot export to");
+
+    permittedDir = temporaryFolder.newFolder("permitted").toPath();
+    otherDir = temporaryFolder.newFolder("other").toPath();
+
+    String permitted = permittedDir.toString();
+    server.invoke(() -> System.setProperty(EXPORT_DATA_DIRS_PROPERTY, permitted));
+  }
+
+  @After
+  public void clearPermittedExportDirectory() {
+    server.invoke(() -> System.clearProperty(EXPORT_DATA_DIRS_PROPERTY));
+  }
+
+  private void connectAs(String user) throws Exception {
+    gfsh.secureConnectAndVerify(locator.getPort(), GfshCommandRule.PortType.locator, user, user);
+  }
+
+  private String exportTo(String option, Path path) {
+    return "export data --member=" + server.getName() + " --region=" + REGION_NAME + " --"
+        + option + "=" + path;
+  }
+
+  /**
+   * Read access to region data on its own does not permit an export.
+   */
+  @Test
+  public void dataReadUserCannotExport() throws Exception {
+    connectAs(READ_ONLY_USER);
+    Path target = permittedDir.resolve("snapshot.gfd");
+
+    gfsh.executeAndAssertThat(exportTo("file", target))
+        .statusIsError()
+        .containsOutput("not authorized for CLUSTER:WRITE");
+
+    assertThat(target).doesNotExist();
+  }
+
+  /**
+   * Permissions are checked before the path, so the target directory makes no difference.
+   */
+  @Test
+  public void dataReadUserIsRefusedForAnyDirectory() throws Exception {
+    connectAs(READ_ONLY_USER);
+    Path target = otherDir.resolve("snapshot.gfd");
+
+    gfsh.executeAndAssertThat(exportTo("file", target))
+        .statusIsError()
+        .containsOutput("not authorized for CLUSTER:WRITE");
+
+    assertThat(target).doesNotExist();
+  }
+
+  /**
+   * The command works for a principal holding both permissions.
+   */
+  @Test
+  public void operatorWithClusterWriteCanExportIntoThePermittedDirectory() throws Exception {
+    connectAs(EXPORT_OPERATOR);
+    Path target = permittedDir.resolve("snapshot.gfd");
+
+    gfsh.executeAndAssertThat(exportTo("file", target))
+        .statusIsSuccess()
+        .containsOutput("Data successfully exported");
+
+    assertThat(target).exists();
+  }
+
+  /**
+   * The directory restriction applies independently of the permission: even a permitted operator
+   * cannot place the snapshot anywhere it likes.
+   */
+  @Test
+  public void operatorCannotExportOutsideThePermittedDirectory() throws Exception {
+    connectAs(EXPORT_OPERATOR);
+    Path target = otherDir.resolve("snapshot.gfd");
+
+    gfsh.executeAndAssertThat(exportTo("file", target)).statusIsError();
+
+    assertThat(target).doesNotExist();
+  }
+
+  /**
+   * Nor can the operator leave the permitted directory with "../".
+   */
+  @Test
+  public void operatorCannotLeavePermittedDirectoryWithParentReference() throws Exception {
+    connectAs(EXPORT_OPERATOR);
+    Path withParentReference = permittedDir.resolve("..").resolve("other");
+
+    gfsh.executeAndAssertThat(exportTo("dir", withParentReference)).statusIsError();
+
+    assertThat(otherDir.resolve(REGION_NAME + ".gfd")).doesNotExist();
+  }
+
+  /**
+   * An existing file outside the permitted directory survives an export aimed at it.
+   */
+  @Test
+  public void existingFileOutsideThePermittedDirectoryIsNotOverwritten() throws Exception {
+    connectAs(EXPORT_OPERATOR);
+    Path existingFile = otherDir.resolve("existing.gfd");
+    String originalContent = "existing content";
+    Files.write(existingFile, originalContent.getBytes(StandardCharsets.UTF_8));
+
+    gfsh.executeAndAssertThat(exportTo("file", existingFile)).statusIsError();
+
+    assertThat(new String(Files.readAllBytes(existingFile), StandardCharsets.UTF_8))
+        .isEqualTo(originalContent);
+  }
+
+  /**
+   * Confirms the read only grant really is read only, so the refusals above are the permission
+   * check taking effect rather than a misconfigured principal.
+   */
+  @Test
+  public void readOnlyUserCanStillReadData() throws Exception {
+    connectAs(READ_ONLY_USER);
+
+    gfsh.executeAndAssertThat("get --region=" + REGION_NAME + " --key=key").statusIsSuccess();
+    gfsh.executeAndAssertThat("put --region=" + REGION_NAME + " --key=k --value=v")
+        .statusIsError()
+        .containsOutput("dataRead not authorized for DATA:WRITE");
+  }
+}

geode-gfsh/src/integrationTest/java/org/apache/geode/management/internal/cli/commands/ExportDataIntegrationTest.java

@@ -17,6 +17,7 @@
 package org.apache.geode.management.internal.cli.commands;
 
 import static org.apache.geode.cache.Region.SEPARATOR;
+import static org.apache.geode.management.internal.cli.functions.ExportDataFunction.EXPORT_DATA_DIRS_PROPERTY;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.assertFalse;
 
@@ -31,6 +32,7 @@
 import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
+import org.junit.contrib.java.lang.system.RestoreSystemProperties;
 import org.junit.rules.TemporaryFolder;
 
 import org.apache.geode.DataSerializable;
@@ -58,6 +60,9 @@ public class ExportDataIntegrationTest {
   @Rule
   public TemporaryFolder tempDir = new TemporaryFolder();
 
+  @Rule
+  public RestoreSystemProperties restoreSystemProperties = new RestoreSystemProperties();
+
   private Region<String, Object> region;
   private Path snapshotFile;
   private Path snapshotDir;
@@ -87,6 +92,8 @@ public void setup() throws Exception {
     region = server.getCache().getRegion(TEST_REGION_NAME);
     loadRegion("value");
     Path basePath = tempDir.getRoot().toPath();
+    // configure the test's temporary folder as an export destination
+    System.setProperty(EXPORT_DATA_DIRS_PROPERTY, basePath.toString());
     snapshotFile = basePath.resolve(SNAPSHOT_FILE);
     snapshotDir = basePath.resolve(SNAPSHOT_DIR);
   }