Exposing the ability to log deprecated settings at non-critical level(#79107) (#79492)

A recent change for the deprecation logs provided the capability to emit deprecation's at critical vs. warning levels, #77482.
However deprecated settings always log at critical level without the ability to express that the setting deprecation is only a
warning.

This commit exposes the ability to set the deprecation level when deprecating a setting.
Relates #78781

Author: masseyke

client/rest/src/main/java/org/elasticsearch/client/Response.java

@@ -136,14 +136,14 @@ public HttpEntity getEntity() {
 
     /**
      * Tests if a string matches the RFC 7234 specification for warning headers.
-     * This assumes that the warn code is always 299 and the warn agent is always
-     * Elasticsearch.
+     * This assumes that the warn code is always 299 or 300 and the warn agent is
+     * always Elasticsearch.
      *
      * @param s the value of a warning header formatted according to RFC 7234
      * @return {@code true} if the input string matches the specification
      */
     private static boolean matchWarningHeaderPatternByPrefix(final String s) {
-        return s.startsWith("299 Elasticsearch-");
+        return s.startsWith("299 Elasticsearch-") || s.startsWith("300 Elasticsearch-");
     }
 
     /**

libs/x-content/src/test/java/org/elasticsearch/xcontent/ObjectParserTests.java

@@ -7,6 +7,7 @@
  */
 package org.elasticsearch.xcontent;
 
+import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.xcontent.XContentParserUtils;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.core.CheckedFunction;
@@ -213,7 +214,8 @@ class TestStruct {
         objectParser.declareField((i, v, c) -> v.test = i.text(), new ParseField("test", "old_test"), ObjectParser.ValueType.STRING);
         objectParser.parse(parser, s, null);
         assertEquals("foo", s.test);
-        assertWarnings(false, "[foo][1:15] Deprecated field [old_test] used, expected [test] instead");
+        assertWarnings(false, new DeprecationWarning(DeprecationLogger.CRITICAL, "[foo][1:15] Deprecated field [old_test] used, " +
+            "expected [test] instead"));
     }
 
     public void testFailOnValueType() throws IOException {

modules/ingest-geoip/src/main/java/org/elasticsearch/ingest/geoip/GeoIpProcessor.java

@@ -23,6 +23,7 @@
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.CheckedSupplier;
+import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.logging.HeaderWarning;
 import org.elasticsearch.common.network.InetAddresses;
 import org.elasticsearch.common.network.NetworkAddress;
@@ -447,8 +448,8 @@ public GeoIpProcessor create(
 
                 boolean valid = metadata.isValid(currentState.metadata().settings());
                 if (valid && metadata.isCloseToExpiration()) {
-                    HeaderWarning.addWarning("database [{}] was not updated for over 25 days, geoip processor will stop working if there " +
-                        "is no update for 30 days", databaseFile);
+                    HeaderWarning.addWarning(DeprecationLogger.CRITICAL, "database [{}] was not updated for over 25 days, geoip processor" +
+                        " will stop working if there is no update for 30 days", databaseFile);
                 }
 
                 return valid;

plugins/discovery-ec2/src/test/java/org/elasticsearch/discovery/ec2/AwsEc2ServiceImplTests.java

@@ -14,7 +14,10 @@
 import com.amazonaws.auth.AWSCredentialsProvider;
 import com.amazonaws.auth.BasicSessionCredentials;
 import com.amazonaws.auth.DefaultAWSCredentialsProviderChain;
+
+import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.settings.MockSecureSettings;
+import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.settings.SettingsException;
 import org.elasticsearch.test.ESTestCase;
@@ -59,8 +62,9 @@ public void testDeprecationOfLoneAccessKey() {
             Ec2ClientSettings.getClientSettings(Settings.builder().setSecureSettings(secureSettings).build())).getCredentials();
         assertThat(credentials.getAWSAccessKeyId(), is("aws_key"));
         assertThat(credentials.getAWSSecretKey(), is(""));
-        assertSettingDeprecationsAndWarnings(new String[]{},
-            "Setting [discovery.ec2.access_key] is set but [discovery.ec2.secret_key] is not, which will be unsupported in future");
+        assertSettingDeprecationsAndWarnings(new Setting<?>[]{},
+            new DeprecationWarning(DeprecationLogger.CRITICAL, "Setting [discovery.ec2.access_key] is set but " +
+                "[discovery.ec2.secret_key] is not, which will be unsupported in future"));
     }
 
     public void testDeprecationOfLoneSecretKey() {
@@ -70,8 +74,9 @@ public void testDeprecationOfLoneSecretKey() {
             Ec2ClientSettings.getClientSettings(Settings.builder().setSecureSettings(secureSettings).build())).getCredentials();
         assertThat(credentials.getAWSAccessKeyId(), is(""));
         assertThat(credentials.getAWSSecretKey(), is("aws_secret"));
-        assertSettingDeprecationsAndWarnings(new String[]{},
-            "Setting [discovery.ec2.secret_key] is set but [discovery.ec2.access_key] is not, which will be unsupported in future");
+        assertSettingDeprecationsAndWarnings(new Setting<?>[]{},
+            new DeprecationWarning(DeprecationLogger.CRITICAL, "Setting [discovery.ec2.secret_key] is set but " +
+                "[discovery.ec2.access_key] is not, which will be unsupported in future"));
     }
 
     public void testRejectionOfLoneSessionToken() {

qa/logging-config/src/test/java/org/elasticsearch/common/logging/JsonLoggerTests.java

@@ -95,7 +95,7 @@ public void testDeprecationWarnMessage() throws IOException {
             );
         }
 
-        assertWarnings("deprecated warn message1");
+        assertWarnings(true, new DeprecationWarning(Level.WARN, "deprecated warn message1"))    ;
     }
 
     public void testDeprecatedMessageWithoutXOpaqueId() throws IOException {

server/src/main/java/org/elasticsearch/cluster/metadata/Metadata.java

@@ -35,6 +35,7 @@
 import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.logging.HeaderWarning;
 import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.settings.Setting;
@@ -1785,7 +1786,7 @@ static void validateDataStreams(SortedMap<String, IndexAbstraction> indicesLooku
                     // log as debug, this method is executed each time a new cluster state is created and
                     // could result in many logs:
                     logger.debug(warning);
-                    HeaderWarning.addWarning(warning);
+                    HeaderWarning.addWarning(DeprecationLogger.CRITICAL, warning);
                 }
             }
         }

server/src/main/java/org/elasticsearch/cluster/metadata/MetadataIndexTemplateService.java

@@ -24,6 +24,7 @@
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.ClusterStateUpdateTask;
 import org.elasticsearch.cluster.service.ClusterService;
+import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.common.Priority;
 import org.elasticsearch.common.Strings;
@@ -490,7 +491,7 @@ public ClusterState addIndexTemplateV2(final ClusterState currentState, final bo
                     .collect(Collectors.joining(",")),
                 name);
             logger.warn(warning);
-            HeaderWarning.addWarning(warning);
+            HeaderWarning.addWarning(DeprecationLogger.CRITICAL, warning);
         }
 
         ComposableIndexTemplate finalIndexTemplate = template;
@@ -816,7 +817,7 @@ static ClusterState innerPutTemplate(final ClusterState currentState, PutRequest
                     .collect(Collectors.joining(",")),
                 request.name);
             logger.warn(warning);
-            HeaderWarning.addWarning(warning);
+            HeaderWarning.addWarning(DeprecationLogger.CRITICAL, warning);
         }
 
         templateBuilder.order(request.order);

server/src/main/java/org/elasticsearch/common/logging/HeaderWarning.java

@@ -8,6 +8,7 @@
 
 package org.elasticsearch.common.logging;
 
+import org.apache.logging.log4j.Level;
 import org.elasticsearch.Build;
 import org.elasticsearch.Version;
 import org.elasticsearch.common.util.concurrent.ThreadContext;
@@ -32,10 +33,11 @@
 public class HeaderWarning {
     /**
      * Regular expression to test if a string matches the RFC7234 specification for warning headers. This pattern assumes that the warn code
-     * is always 299. Further, this pattern assumes that the warn agent represents a version of Elasticsearch including the build hash.
+     * is always 299 or 300. Further, this pattern assumes that the warn agent represents a version of Elasticsearch including the build
+     * hash.
      */
     public static final Pattern WARNING_HEADER_PATTERN = Pattern.compile(
-        "299 " + // warn code
+        "(?:299|300) " + // log level code
             "Elasticsearch-" + // warn agent
             "\\d+\\.\\d+\\.\\d+(?:-(?:alpha|beta|rc)\\d+)?(?:-SNAPSHOT)?-" + // warn agent
             "(?:[a-f0-9]{7}(?:[a-f0-9]{33})?|unknown) " + // warn agent
@@ -53,15 +55,16 @@ public class HeaderWarning {
 
     /*
      * RFC7234 specifies the warning format as warn-code <space> warn-agent <space> "warn-text" [<space> "warn-date"]. Here, warn-code is a
-     * three-digit number with various standard warn codes specified. The warn code 299 is apt for our purposes as it represents a
-     * miscellaneous persistent warning (can be presented to a human, or logged, and must not be removed by a cache). The warn-agent is an
-     * arbitrary token; here we use the Elasticsearch version and build hash. The warn text must be quoted. The warn-date is an optional
-     * quoted field that can be in a variety of specified date formats; here we use RFC 1123 format.
+     * three-digit number with various standard warn codes specified, and is left off of this static prefix so that it can be added based
+     * on the log level received. The warn code will be either 299 or 300 at runtime, which are apt for our purposes as
+     * they represent miscellaneous persistent warnings (can be presented to a human, or logged, and must not be removed by a cache).
+     * The warn-agent is an arbitrary token; here we use the Elasticsearch version and build hash. The warn text must be quoted. The
+     * warn-date is an optional quoted field that can be in a variety of specified date formats; here we use RFC 1123 format.
      */
     private static final String WARNING_PREFIX =
         String.format(
             Locale.ROOT,
-            "299 Elasticsearch-%s%s-%s",
+            " Elasticsearch-%s%s-%s",
             Version.CURRENT.toString(),
             Build.CURRENT.isSnapshot() ? "-SNAPSHOT" : "",
             Build.CURRENT.hash());
@@ -189,14 +192,15 @@ private static boolean assertWarningValue(final String s, final String warningVa
      * Format a warning string in the proper warning format by prepending a warn code, warn agent, wrapping the warning string in quotes,
      * and appending the RFC 7231 date.
      *
+     * @param level the level of the warning - Level.WARN or DeprecationLogger.CRITICAL
      * @param s the warning string to format
      * @return a warning value formatted according to RFC 7234
      */
-    public static String formatWarning(final String s) {
+    public static String formatWarning(final Level level, final String s) {
         // Assume that the common scenario won't have a string to escape and encode.
-        int length = WARNING_PREFIX.length() + s.length() + 3;
+        int length = WARNING_PREFIX.length() + s.length() + 6;
         final StringBuilder sb = new StringBuilder(length);
-        sb.append(WARNING_PREFIX).append(" \"").append(escapeAndEncode(s)).append("\"");
+        sb.append(level.intLevel() + WARNING_PREFIX).append(" \"").append(escapeAndEncode(s)).append("\"");
         return sb.toString();
     }
 
@@ -310,16 +314,21 @@ public static String getXOpaqueId() {
             .orElse("");
     }
 
-    public static void addWarning(String message, Object... params) {
-        addWarning(THREAD_CONTEXT, message, params);
+    public static void addWarning(Level level, String message, Object... params) {
+        addWarning(THREAD_CONTEXT, level, message, params);
     }
 
     // package scope for testing
     static void addWarning(Set<ThreadContext> threadContexts, String message, Object... params) {
+        addWarning(threadContexts, DeprecationLogger.CRITICAL, message, params);
+    }
+
+    // package scope for testing
+    static void addWarning(Set<ThreadContext> threadContexts, Level level, String message, Object... params) {
         final Iterator<ThreadContext> iterator = threadContexts.iterator();
         if (iterator.hasNext()) {
             final String formattedMessage = LoggerMessageFormat.format(message, params);
-            final String warningHeaderValue = formatWarning(formattedMessage);
+            final String warningHeaderValue = formatWarning(level, formattedMessage);
             assert WARNING_HEADER_PATTERN.matcher(warningHeaderValue).matches();
             assert extractWarningValueFromWarningHeader(warningHeaderValue, false)
                 .equals(escapeAndEncode(formattedMessage));

server/src/main/java/org/elasticsearch/common/logging/HeaderWarningAppender.java

@@ -35,10 +35,10 @@ public void append(LogEvent event) {
             String messagePattern = esLogMessage.getMessagePattern();
             Object[] arguments = esLogMessage.getArguments();
 
-            HeaderWarning.addWarning(messagePattern, arguments);
+            HeaderWarning.addWarning(event.getLevel(), messagePattern, arguments);
         } else {
             final String formattedMessage = event.getMessage().getFormattedMessage();
-            HeaderWarning.addWarning(formattedMessage);
+            HeaderWarning.addWarning(event.getLevel(), formattedMessage);
         }
     }
 

server/src/main/java/org/elasticsearch/common/settings/Setting.java

@@ -100,10 +100,15 @@ public enum Property {
         Final,
 
         /**
-         * mark this setting as deprecated
+         * mark this setting as deprecated (critical level)
          */
         Deprecated,
 
+        /**
+         * mark this setting as deprecated (warning level)
+         */
+        DeprecatedWarning,
+
         /**
          * Node scope
          */
@@ -170,6 +175,9 @@ private Setting(Key key, @Nullable Setting<T> fallbackSetting, Function<Settings
             if (propertiesAsSet.contains(Property.Dynamic) && propertiesAsSet.contains(Property.OperatorDynamic)) {
                 throw new IllegalArgumentException("setting [" + key + "] cannot be both dynamic and operator dynamic");
             }
+            if (propertiesAsSet.contains(Property.Deprecated) && propertiesAsSet.contains(Property.DeprecatedWarning)) {
+                throw new IllegalArgumentException("setting [" + key + "] cannot be deprecated at both critical and warning levels");
+            }
             checkPropertyRequiresIndexScope(propertiesAsSet, Property.NotCopyableOnResize);
             checkPropertyRequiresIndexScope(propertiesAsSet, Property.InternalIndex);
             checkPropertyRequiresIndexScope(propertiesAsSet, Property.PrivateIndex);
@@ -382,7 +390,11 @@ public boolean hasIndexScope() {
      * Returns <code>true</code> if this setting is deprecated, otherwise <code>false</code>
      */
     public boolean isDeprecated() {
-        return properties.contains(Property.Deprecated);
+        return properties.contains(Property.Deprecated) || properties.contains(Property.DeprecatedWarning);
+    }
+
+    private boolean isDeprecatedWarningOnly() {
+        return properties.contains(Property.DeprecatedWarning);
     }
 
     /**
@@ -561,13 +573,16 @@ void checkDeprecation(Settings settings) {
         if (this.isDeprecated() && this.exists(settings)) {
             // It would be convenient to show its replacement key, but replacement is often not so simple
             final String key = getKey();
-
             DeprecationCategory category = this.isSecure(settings) ? DeprecationCategory.SECURITY : DeprecationCategory.SETTINGS;
             List<String> skipTheseDeprecations = settings.getAsList("deprecation.skip_deprecated_settings");
             if (Regex.simpleMatch(skipTheseDeprecations, key) == false) {
-                Settings.DeprecationLoggerHolder.deprecationLogger
-                    .critical(category, key, "[{}] setting was deprecated in Elasticsearch and will be removed in a future release! "
-                        + "See the breaking changes documentation for the next major version.", key);
+                String message = "[{}] setting was deprecated in Elasticsearch and will be removed in a future release! "
+                    + "See the breaking changes documentation for the next major version.";
+                if (this.isDeprecatedWarningOnly()) {
+                    Settings.DeprecationLoggerHolder.deprecationLogger.warn(category, key, message, key);
+                } else {
+                    Settings.DeprecationLoggerHolder.deprecationLogger.critical(category, key, message, key);
+                }
             }
         }
     }