Adding deprecation info API check for client transport profile setting (#76999)

In 8.0, access to the transport client has been removed, so the transport.profiles.*.xpack.security.type
setting is gone. This commit adds a deprecation info API check for this property.
Relates #42404 #43236

Author: masseyke

x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/DeprecationChecks.java

@@ -97,6 +97,7 @@ private DeprecationChecks() {
                     NodeDeprecationChecks::checkImplicitlyDisabledSecurityOnBasicAndTrial,
                     NodeDeprecationChecks::checkSearchRemoteSettings,
                     NodeDeprecationChecks::checkMonitoringExporterPassword,
+                    NodeDeprecationChecks::checkTransportClientProfilesFilterSetting,
                     NodeDeprecationChecks::checkDelayClusterStateRecoverySettings,
                     NodeDeprecationChecks::checkFixedAutoQueueSizeThreadpool,
                     NodeDeprecationChecks::checkJoinTimeoutSetting,

x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/NodeDeprecationChecks.java

@@ -666,6 +666,38 @@ static DeprecationIssue checkClusterRoutingAllocationIncludeRelocationsSetting(f
         );
     }
 
+    static DeprecationIssue checkTransportClientProfilesFilterSetting(
+        final Settings settings,
+        final PluginsAndModules pluginsAndModules,
+        ClusterState cs,
+        XPackLicenseState licenseState
+    ) {
+        final Setting.AffixSetting<String> transportTypeProfileSetting =
+            Setting.affixKeySetting("transport.profiles.","xpack.security.type", s -> Setting.simpleString(s));
+        List<Setting<?>> transportProfiles = transportTypeProfileSetting.getAllConcreteSettings(settings)
+            .sorted(Comparator.comparing(Setting::getKey)).collect(Collectors.toList());
+
+        if (transportProfiles.isEmpty()) {
+            return null;
+        }
+
+        final String transportProfilesSettings = transportProfiles.stream().map(Setting::getKey).collect(Collectors.joining(","));
+        final String message = String.format(
+            Locale.ROOT,
+            "settings [%s] are deprecated and will be removed in the next major version",
+            transportProfilesSettings
+        );
+        final String details = String.format(
+            Locale.ROOT,
+            "transport client will be removed in the next major version so transport client related settings [%s] must be removed",
+            transportProfilesSettings
+        );
+
+        final String url = "https://www.elastic.co/guide/en/elasticsearch/reference/master/migrating-8.0" +
+            ".html#separating-node-and-client-traffic";
+        return new DeprecationIssue(DeprecationIssue.Level.CRITICAL, message, url, details, false, null);
+    }
+
     static DeprecationIssue checkDelayClusterStateRecoverySettings(final Settings settings,
                                                                    final PluginsAndModules pluginsAndModules,
                                                                    final ClusterState clusterState,

x-pack/plugin/deprecation/src/test/java/org/elasticsearch/xpack/deprecation/NodeDeprecationChecksTests.java

@@ -962,6 +962,44 @@ public void testImplicitlyConfiguredSecurityOnGoldPlus() {
         assertThat(issues, empty());
     }
 
+    public void testCheckTransportClientProfilesFilterSetting() {
+        final int numProfiles = randomIntBetween(1, 3);
+        final String[] profileNames = new String[numProfiles];
+        final Settings.Builder b = Settings.builder();
+        for (int k = 0; k < numProfiles; k++) {
+            profileNames[k] = randomAlphaOfLength(5);
+            b.put("transport.profiles." + profileNames[k] + ".xpack.security.type", randomAlphaOfLengthBetween(3, 10));
+        }
+        final Settings settings = b.build();
+        final XPackLicenseState licenseState = new XPackLicenseState(Settings.EMPTY, () -> 0);
+        DeprecationIssue issue = NodeDeprecationChecks.checkTransportClientProfilesFilterSetting(settings, null, null, licenseState);
+        final String expectedUrl =
+            "https://www.elastic.co/guide/en/elasticsearch/reference/master/migrating-8.0.html#separating-node-and-client-traffic";
+        final String joinedNames = Arrays
+            .stream(profileNames)
+            .map(s -> "transport.profiles." + s + ".xpack.security.type")
+            .sorted()
+            .collect(Collectors.joining(","));
+
+        assertThat(issue, equalTo(new DeprecationIssue(
+            DeprecationIssue.Level.CRITICAL,
+            String.format(
+                Locale.ROOT,
+                "settings [%s] are deprecated and will be removed in the next major version",
+                joinedNames
+            ),
+            expectedUrl,
+            String.format(
+                Locale.ROOT,
+                "transport client will be removed in the next major version so transport client related settings [%s] must be removed",
+                joinedNames
+            ), false, null)));
+
+        // test for absence of deprecated exporter passwords
+        issue = NodeDeprecationChecks.checkTransportClientProfilesFilterSetting(Settings.builder().build(), null, null, licenseState);
+        assertThat(issue, nullValue());
+    }
+
     public void testCheckDelayClusterStateRecoverySettings() {
         Settings settings = Settings.builder()
             .put(GatewayService.EXPECTED_NODES_SETTING.getKey(), randomIntBetween(2, 10))