Remove support for properties

This commit removes support for properties syntax and config files:
 - removed support for elasticsearch.properties
 - removed support for logging.properties
 - removed support for properties content detection in REST APIs
 - removed support for properties content detection in Java API

Relates #19398

core/src/main/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoader.java

@@ -1,88 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch 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.elasticsearch.common.settings.loader;
-
-import org.apache.lucene.util.IOUtils;
-import org.elasticsearch.ElasticsearchParseException;
-import org.elasticsearch.common.io.FastStringReader;
-import org.elasticsearch.common.io.stream.StreamInput;
-
-import java.io.Closeable;
-import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Properties;
-import java.util.function.Supplier;
-
-/**
- * Settings loader that loads (parses) the settings in a properties format.
- */
-public class PropertiesSettingsLoader implements SettingsLoader {
-
-    @Override
-    public Map<String, String> load(String source) throws IOException {
-        return load(() -> new FastStringReader(source), (reader, props) -> props.load(reader));
-    }
-
-    @Override
-    public Map<String, String> load(byte[] source) throws IOException {
-        return load(() -> StreamInput.wrap(source), (inStream, props) -> props.load(inStream));
-    }
-
-    private <T extends Closeable> Map<String, String> load(
-            Supplier<T> supplier,
-            IOExceptionThrowingBiConsumer<T, Properties> properties
-    ) throws IOException {
-        T t = null;
-        try {
-            t = supplier.get();
-            final Properties props = new NoDuplicatesProperties();
-            properties.accept(t, props);
-            final Map<String, String> result = new HashMap<>();
-            for (Map.Entry entry : props.entrySet()) {
-                result.put((String) entry.getKey(), (String) entry.getValue());
-            }
-            return result;
-        } finally {
-            IOUtils.closeWhileHandlingException(t);
-        }
-    }
-
-    @FunctionalInterface
-    private interface IOExceptionThrowingBiConsumer<T, U> {
-        void accept(T t, U u) throws IOException;
-    }
-
-    class NoDuplicatesProperties extends Properties {
-        @Override
-        public synchronized Object put(Object key, Object value) {
-            final Object previousValue = super.put(key, value);
-            if (previousValue != null) {
-                throw new ElasticsearchParseException(
-                        "duplicate settings key [{}] found, previous value [{}], current value [{}]",
-                        key,
-                        previousValue,
-                        value
-                );
-            }
-            return previousValue;
-        }
-    }
-}

core/src/main/java/org/elasticsearch/common/settings/loader/SettingsLoaderFactory.java

@@ -48,11 +48,8 @@ public final class SettingsLoaderFactory {
             return new JsonSettingsLoader(false);
         } else if (resourceName.endsWith(".yml") || resourceName.endsWith(".yaml")) {
             return new YamlSettingsLoader(false);
-        } else if (resourceName.endsWith(".properties")) {
-            return new PropertiesSettingsLoader();
         } else {
-            // lets default to the json one
-            return new JsonSettingsLoader(false);
+            throw new IllegalArgumentException("unable to detect content type from resource name [" + resourceName + "]");
         }
     }
 
@@ -72,11 +69,11 @@ public final class SettingsLoaderFactory {
     public static SettingsLoader loaderFromSource(String source) {
         if (source.indexOf('{') != -1 && source.indexOf('}') != -1) {
             return new JsonSettingsLoader(true);
-        }
-        if (source.indexOf(':') != -1) {
+        } else if (source.indexOf(':') != -1) {
             return new YamlSettingsLoader(true);
+        } else {
+            throw new IllegalArgumentException("unable to detect content type from source [" + source + "]");
         }
-        return new PropertiesSettingsLoader();
     }
 
 }

core/src/main/java/org/elasticsearch/node/internal/InternalSettingsPreparer.java

@@ -51,7 +51,7 @@ import static org.elasticsearch.common.Strings.cleanPath;
  */
 public class InternalSettingsPreparer {
 
-    private static final String[] ALLOWED_SUFFIXES = {".yml", ".yaml", ".json", ".properties"};
+    private static final String[] ALLOWED_SUFFIXES = {".yml", ".yaml", ".json"};
     static final String PROPERTY_DEFAULTS_PREFIX = "default.";
     static final Predicate<String> PROPERTY_DEFAULTS_PREDICATE = key -> key.startsWith(PROPERTY_DEFAULTS_PREFIX);
 

core/src/test/java/org/elasticsearch/common/logging/LoggingConfigurationTests.java

@@ -95,23 +95,6 @@ public class LoggingConfigurationTests extends ESTestCase {
         assertThat(logSettings.get("json"), is("foo"));
     }
 
-    public void testResolvePropertiesLoggingConfig() throws Exception {
-        Path tmpDir = createTempDir();
-        Path loggingConf = tmpDir.resolve(loggingConfiguration("properties"));
-        Files.write(loggingConf, "key: value".getBytes(StandardCharsets.UTF_8));
-        Environment environment = new Environment(
-                Settings.builder()
-                    .put(Environment.PATH_CONF_SETTING.getKey(), tmpDir.toAbsolutePath())
-                    .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toString())
-                    .build());
-
-        Settings.Builder builder = Settings.builder();
-        LogConfigurator.resolveConfig(environment, builder);
-
-        Settings logSettings = builder.build();
-        assertThat(logSettings.get("key"), is("value"));
-    }
-
     public void testResolveYamlLoggingConfig() throws Exception {
         Path tmpDir = createTempDir();
         Path loggingConf1 = tmpDir.resolve(loggingConfiguration("yml"));

core/src/test/java/org/elasticsearch/common/settings/loader/PropertiesSettingsLoaderTests.java

@@ -1,57 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch 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.elasticsearch.common.settings.loader;
-
-import org.elasticsearch.ElasticsearchParseException;
-import org.elasticsearch.test.ESTestCase;
-import org.junit.Before;
-
-import java.io.IOException;
-import java.nio.charset.Charset;
-
-public class PropertiesSettingsLoaderTests extends ESTestCase {
-
-    private PropertiesSettingsLoader loader;
-
-    @Before
-    public void setUp() throws Exception {
-        super.setUp();
-        loader = new PropertiesSettingsLoader();
-    }
-
-    public void testDuplicateKeyFromStringThrowsException() throws IOException {
-        final ElasticsearchParseException e = expectThrows(ElasticsearchParseException.class, () -> loader.load("foo=bar\nfoo=baz"));
-        assertEquals(e.getMessage(), "duplicate settings key [foo] found, previous value [bar], current value [baz]");
-    }
-
-    public void testDuplicateKeysFromBytesThrowsException() throws IOException {
-        final ElasticsearchParseException e = expectThrows(
-                ElasticsearchParseException.class,
-                () -> loader.load("foo=bar\nfoo=baz".getBytes(Charset.defaultCharset()))
-        );
-        assertEquals(e.getMessage(), "duplicate settings key [foo] found, previous value [bar], current value [baz]");
-    }
-
-    public void testThatNoDuplicatesPropertiesDoesNotAcceptNullValues() {
-        final PropertiesSettingsLoader.NoDuplicatesProperties properties = loader.new NoDuplicatesProperties();
-        expectThrows(NullPointerException.class, () -> properties.put("key", null));
-    }
-
-}

core/src/test/java/org/elasticsearch/search/preference/SearchPreferenceIT.java

@@ -98,7 +98,7 @@ public class SearchPreferenceIT extends ESIntegTestCase {
     }
 
     public void testSimplePreference() throws Exception {
-        client().admin().indices().prepareCreate("test").setSettings("number_of_replicas=1").get();
+        client().admin().indices().prepareCreate("test").setSettings("{\"number_of_replicas\": 1}").get();
         ensureGreen();
 
         client().prepareIndex("test", "type1").setSource("field1", "value1").execute().actionGet();
@@ -131,7 +131,7 @@ public class SearchPreferenceIT extends ESIntegTestCase {
     }
 
     public void testReplicaPreference() throws Exception {
-        client().admin().indices().prepareCreate("test").setSettings("number_of_replicas=0").get();
+        client().admin().indices().prepareCreate("test").setSettings("{\"number_of_replicas\": 0}").get();
         ensureGreen();
 
         client().prepareIndex("test", "type1").setSource("field1", "value1").execute().actionGet();
@@ -147,7 +147,7 @@ public class SearchPreferenceIT extends ESIntegTestCase {
         SearchResponse resp = client().prepareSearch().setQuery(matchAllQuery()).setPreference("_replica_first").execute().actionGet();
         assertThat(resp.getHits().totalHits(), equalTo(1L));
 
-        client().admin().indices().prepareUpdateSettings("test").setSettings("number_of_replicas=1").get();
+        client().admin().indices().prepareUpdateSettings("test").setSettings("{\"number_of_replicas\": 1}").get();
         ensureGreen("test");
 
         resp = client().prepareSearch().setQuery(matchAllQuery()).setPreference("_replica").execute().actionGet();

docs/reference/migration/migrate_5_0/java.asciidoc

@@ -312,6 +312,11 @@ Removed the `getMemoryAvailable` method from `OsStats`, which could be previousl
 are now three options (NONE, IMMEDIATE, and WAIT_FOR). `setRefresh(IMMEDIATE)` has the same behavior
 as `setRefresh(true)` used to have. See `setRefreshPolicy`'s javadoc for more.
 
+==== Remove properties support
+
+Some Java APIs (e.g., `IndicesAdminClient#setSettings`) would support Java properties syntax
+(line-delimited key=value pairs). This support has been removed.
+
 === Render Search Template Java API has been removed
 
 The Render Search Template Java API including `RenderSearchTemplateAction`, `RenderSearchTemplateRequest` and
@@ -319,3 +324,4 @@ The Render Search Template Java API including `RenderSearchTemplateAction`, `Ren
  This Search Template API is now included in the `lang-mustache` module and the `simulate` flag must be set on the
  `SearchTemplateRequest` object.
 
+

docs/reference/migration/migrate_5_0/rest.asciidoc

@@ -74,3 +74,8 @@ The `PUT /_scripts/{lang}/{id}/_create` endpoint that previously allowed to crea
 The `PUT /_search/template/{id}/_create` endpoint that previously allowed to create
  indexed template has been removed. Indexed templates have been replaced
  by <<pre-registered-templates, Pre-registered templates>>.
+
+==== Remove properties support
+
+Some REST endpoints (e.g., cluster update index settings) supported detecting content in the Java
+properties format (line-delimited key=value pairs). This support has been removed.

docs/reference/migration/migrate_5_0/settings.asciidoc

@@ -229,6 +229,11 @@ Elasticsearch could previously be configured on the command line by
 setting settings via `--name.of.setting value.of.setting`. This feature
 has been removed. Instead, use `-Ename.of.setting=value.of.setting`.
 
+==== Remove support for .properties config files
+
+The Elasticsearch configuration and logging configuration can no longer be stored in the Java
+properties file format (line-delimited key=value pairs with a `.properties` extension).
+
 ==== Discovery Settings
 
 The `discovery.zen.minimum_master_node` must be set for nodes that have