Add 'monitor_snapshot' cluster privilege (elastic#50489)

This adds a new cluster privilege `monitor_snapshot` which is a restricted
version of `create_snapshot`, granting the same privileges to view
snapshot and repository info and status but not granting the actual
privilege to create a snapshot. 

Co-authored-by: Anton Shuvaev <anton.shuvaev91@gmail.com>

x-pack/docs/en/rest-api/security/get-builtin-privileges.asciidoc

@@ -87,6 +87,7 @@ A successful call returns an object with "cluster" and "index" fields.
     "monitor_data_frame_transforms",
     "monitor_ml",
     "monitor_rollup",
+    "monitor_snapshot",
     "monitor_transform",
     "monitor_watcher",
     "none",

x-pack/docs/en/security/authorization/privileges.asciidoc

@@ -16,6 +16,9 @@ settings update, rerouting, or managing users and roles.
 Privileges to create snapshots for existing repositories. Can also list and view
 details on existing repositories and snapshots.
 
+`monitor_snapshot`::
+Privileges to list and view details on existing repositories and snapshots.
+
 `manage`::
 Builds on `monitor` and adds cluster operations that change values in the cluster.
 This includes snapshotting, updating settings, and rerouting. It also includes 

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/authz/privilege/ClusterPrivilegeResolver.java

@@ -66,6 +66,8 @@ public class ClusterPrivilegeResolver {
         Set.of("cluster:admin/xpack/ccr/*", ClusterStateAction.NAME, HasPrivilegesAction.NAME);
     private static final Set<String> CREATE_SNAPSHOT_PATTERN = Set.of(CreateSnapshotAction.NAME, SnapshotsStatusAction.NAME + "*",
         GetSnapshotsAction.NAME, SnapshotsStatusAction.NAME, GetRepositoriesAction.NAME);
+    private static final Set<String> MONITOR_SNAPSHOT_PATTERN = Set.of(SnapshotsStatusAction.NAME + "*", GetSnapshotsAction.NAME,
+            SnapshotsStatusAction.NAME, GetRepositoriesAction.NAME);
     private static final Set<String> READ_CCR_PATTERN = Set.of(ClusterStateAction.NAME, HasPrivilegesAction.NAME);
     private static final Set<String> MANAGE_ILM_PATTERN = Set.of("cluster:admin/ilm/*");
     private static final Set<String> READ_ILM_PATTERN = Set.of(GetLifecycleAction.NAME, GetStatusAction.NAME);
@@ -109,6 +111,7 @@ public class ClusterPrivilegeResolver {
     public static final NamedClusterPrivilege MANAGE_CCR =            new ActionClusterPrivilege("manage_ccr", MANAGE_CCR_PATTERN);
     public static final NamedClusterPrivilege READ_CCR = new ActionClusterPrivilege("read_ccr", READ_CCR_PATTERN);
     public static final NamedClusterPrivilege CREATE_SNAPSHOT = new ActionClusterPrivilege("create_snapshot", CREATE_SNAPSHOT_PATTERN);
+    public static final NamedClusterPrivilege MONITOR_SNAPSHOT = new ActionClusterPrivilege("monitor_snapshot", MONITOR_SNAPSHOT_PATTERN);
     public static final NamedClusterPrivilege MANAGE_ILM = new ActionClusterPrivilege("manage_ilm", MANAGE_ILM_PATTERN);
     public static final NamedClusterPrivilege READ_ILM = new ActionClusterPrivilege("read_ilm", READ_ILM_PATTERN);
     public static final NamedClusterPrivilege MANAGE_SLM = new ActionClusterPrivilege("manage_slm", MANAGE_SLM_PATTERN);
@@ -146,6 +149,7 @@ public class ClusterPrivilegeResolver {
         MANAGE_CCR,
         READ_CCR,
         CREATE_SNAPSHOT,
+        MONITOR_SNAPSHOT,
         MANAGE_ILM,
         READ_ILM,
         MANAGE_SLM,

x-pack/plugin/security/src/test/java/org/elasticsearch/integration/ClusterPrivilegeTests.java

@@ -36,13 +36,17 @@ public class ClusterPrivilegeTests extends AbstractPrivilegeTestCase {
                     "    - names: 'someindex'\n" +
                     "      privileges: [ all ]\n" +
                     "role_d:\n" +
-                    "  cluster: [ create_snapshot ]\n";
+                    "  cluster: [ create_snapshot ]\n" +
+                    "\n" +
+                    "role_e:\n" +
+                    "  cluster: [ monitor_snapshot]\n";
 
     private static final String USERS_ROLES =
                     "role_a:user_a\n" +
                     "role_b:user_b\n" +
                     "role_c:user_c\n" +
-                    "role_d:user_d\n";
+                    "role_d:user_d\n" +
+                    "role_e:user_e\n";
 
     private static Path repositoryLocation;
 
@@ -81,7 +85,8 @@ protected String configUsers() {
             "user_a:" + usersPasswdHashed + "\n" +
             "user_b:" + usersPasswdHashed + "\n" +
             "user_c:" + usersPasswdHashed + "\n" +
-            "user_d:" + usersPasswdHashed + "\n";
+            "user_d:" + usersPasswdHashed + "\n" +
+            "user_e:" + usersPasswdHashed + "\n";
     }
 
     @Override
@@ -139,6 +144,19 @@ public void testThatClusterPrivilegesWorkAsExpectedViaHttp() throws Exception {
         assertAccessIsDenied("user_d", "GET", "/_nodes/infos");
         assertAccessIsDenied("user_d", "POST", "/_cluster/reroute");
         assertAccessIsDenied("user_d", "PUT", "/_cluster/settings", "{ \"transient\" : { \"search.default_search_timeout\": \"1m\" } }");
+
+        // user_e can view repos and snapshots on existing repos, everything else is DENIED
+        assertAccessIsDenied("user_e", "GET", "/_cluster/state");
+        assertAccessIsDenied("user_e", "GET", "/_cluster/health");
+        assertAccessIsDenied("user_e", "GET", "/_cluster/settings");
+        assertAccessIsDenied("user_e", "GET", "/_cluster/stats");
+        assertAccessIsDenied("user_e", "GET", "/_cluster/pending_tasks");
+        assertAccessIsDenied("user_e", "GET", "/_nodes/stats");
+        assertAccessIsDenied("user_e", "GET", "/_nodes/hot_threads");
+        assertAccessIsDenied("user_e", "GET", "/_nodes/infos");
+        assertAccessIsDenied("user_e", "POST", "/_cluster/reroute");
+        assertAccessIsDenied("user_e", "PUT", "/_cluster/settings", "{ \"transient\" : { \"search.default_search_timeout\": \"1m\" } }");
+
     }
 
     public void testThatSnapshotAndRestore() throws Exception {
@@ -147,6 +165,7 @@ public void testThatSnapshotAndRestore() throws Exception {
         assertAccessIsDenied("user_b", "PUT", "/_snapshot/my-repo", repoJson);
         assertAccessIsDenied("user_c", "PUT", "/_snapshot/my-repo", repoJson);
         assertAccessIsDenied("user_d", "PUT", "/_snapshot/my-repo", repoJson);
+        assertAccessIsDenied("user_e", "PUT", "/_snapshot/my-repo", repoJson);
         assertAccessIsAllowed("user_a", "PUT", "/_snapshot/my-repo", repoJson);
 
         Request createBar = new Request("PUT", "/someindex/_doc/1");
@@ -155,16 +174,19 @@ public void testThatSnapshotAndRestore() throws Exception {
         assertAccessIsDenied("user_a", createBar);
         assertAccessIsDenied("user_b", createBar);
         assertAccessIsDenied("user_d", createBar);
+        assertAccessIsDenied("user_e", createBar);
         assertAccessIsAllowed("user_c", createBar);
 
         assertAccessIsDenied("user_b", "PUT", "/_snapshot/my-repo/my-snapshot", "{ \"indices\": \"someindex\" }");
         assertAccessIsDenied("user_c", "PUT", "/_snapshot/my-repo/my-snapshot", "{ \"indices\": \"someindex\" }");
+        assertAccessIsDenied("user_e", "PUT", "/_snapshot/my-repo/my-snapshot", "{ \"indices\": \"someindex\" }");
         assertAccessIsAllowed("user_a", "PUT", "/_snapshot/my-repo/my-snapshot", "{ \"indices\": \"someindex\" }");
 
         assertAccessIsDenied("user_b", "GET", "/_snapshot/my-repo/my-snapshot/_status");
         assertAccessIsDenied("user_c", "GET", "/_snapshot/my-repo/my-snapshot/_status");
         assertAccessIsAllowed("user_a", "GET", "/_snapshot/my-repo/my-snapshot/_status");
         assertAccessIsAllowed("user_d", "GET", "/_snapshot/my-repo/my-snapshot/_status");
+        assertAccessIsAllowed("user_e", "GET", "/_snapshot/my-repo/my-snapshot/_status");
 
         // This snapshot needs to be finished in order to be restored
         waitForSnapshotToFinish("my-repo", "my-snapshot");
@@ -175,28 +197,33 @@ public void testThatSnapshotAndRestore() throws Exception {
         assertAccessIsDenied("user_a", "DELETE", "/someindex");
         assertAccessIsDenied("user_b", "DELETE", "/someindex");
         assertAccessIsDenied("user_d", "DELETE", "/someindex");
+        assertAccessIsDenied("user_e", "DELETE", "/someindex");
         assertAccessIsAllowed("user_c", "DELETE", "/someindex");
 
         Request restoreSnapshotRequest = new Request("POST", "/_snapshot/my-repo/my-snapshot/_restore");
         restoreSnapshotRequest.addParameter("wait_for_completion", "true");
         assertAccessIsDenied("user_b", restoreSnapshotRequest);
         assertAccessIsDenied("user_c", restoreSnapshotRequest);
         assertAccessIsDenied("user_d", restoreSnapshotRequest);
+        assertAccessIsDenied("user_e", restoreSnapshotRequest);
         assertAccessIsAllowed("user_a", restoreSnapshotRequest);
 
         assertAccessIsDenied("user_a", "GET", "/someindex/_doc/1");
         assertAccessIsDenied("user_b", "GET", "/someindex/_doc/1");
         assertAccessIsDenied("user_d", "GET", "/someindex/_doc/1");
+        assertAccessIsDenied("user_e", "GET", "/someindex/_doc/1");
         assertAccessIsAllowed("user_c", "GET", "/someindex/_doc/1");
 
         assertAccessIsDenied("user_b", "DELETE", "/_snapshot/my-repo/my-snapshot");
         assertAccessIsDenied("user_c", "DELETE", "/_snapshot/my-repo/my-snapshot");
         assertAccessIsDenied("user_d", "DELETE", "/_snapshot/my-repo/my-snapshot");
+        assertAccessIsDenied("user_e", "DELETE", "/_snapshot/my-repo/my-snapshot");
         assertAccessIsAllowed("user_a", "DELETE", "/_snapshot/my-repo/my-snapshot");
 
         assertAccessIsDenied("user_b", "DELETE", "/_snapshot/my-repo");
         assertAccessIsDenied("user_c", "DELETE", "/_snapshot/my-repo");
         assertAccessIsDenied("user_d", "DELETE", "/_snapshot/my-repo");
+        assertAccessIsDenied("user_e", "DELETE", "/_snapshot/my-repo");
         assertAccessIsAllowed("user_a", "DELETE", "/_snapshot/my-repo");
     }
 

x-pack/plugin/src/test/resources/rest-api-spec/test/privileges/11_builtin.yml

@@ -15,5 +15,5 @@ setup:
   # This is fragile - it needs to be updated every time we add a new cluster/index privilege
   # I would much prefer we could just check that specific entries are in the array, but we don't have
   # an assertion for that
-  - length: { "cluster" : 33 }
+  - length: { "cluster" : 34 }
   - length: { "index" : 17 }