Settings: Fix settings reading to account for defaults (#22871)

In #22762, settings preparation during bootstrap was changed slightly to
account for SecureSettings, by starting with a fresh settings builder
after reading the initial configuration. However, this the defaults from
system properties were never re-read. This change fixes that bug (which
was never released).

closes #22861

1 files changed, 23 insertions, 1 deletions

diff --git a/core/src/test/java/org/elasticsearch/node/internal/InternalSettingsPreparerTests.java b/core/src/test/java/org/elasticsearch/node/internal/InternalSettingsPreparerTests.java
index 58b6fd3959..21c1811616 100644
--- a/core/src/test/java/org/elasticsearch/node/internal/InternalSettingsPreparerTests.java
+++ b/core/src/test/java/org/elasticsearch/node/internal/InternalSettingsPreparerTests.java
@@ -35,25 +35,32 @@ import org.junit.Before;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Map;
 
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 
 public class InternalSettingsPreparerTests extends ESTestCase {
 
+    Path homeDir;
     Settings baseEnvSettings;
 
     @Before
     public void createBaseEnvSettings() {
+        homeDir = createTempDir();
         baseEnvSettings = Settings.builder()
-            .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir())
+            .put(Environment.PATH_HOME_SETTING.getKey(), homeDir)
             .build();
     }
 
     @After
     public void clearBaseEnvSettings() {
+        homeDir = null;
         baseEnvSettings = null;
     }
 
@@ -174,4 +181,19 @@ public class InternalSettingsPreparerTests extends ESTestCase {
         Setting<SecureString> fakeSetting = SecureSetting.secureString("foo", null, false);
         assertEquals("secret", fakeSetting.get(env.settings()).toString());
     }
+
+    public void testDefaultProperties() throws Exception {
+        Map<String, String> props = Collections.singletonMap("default.setting", "foo");
+        Environment env = InternalSettingsPreparer.prepareEnvironment(baseEnvSettings, null, props);
+        assertEquals("foo", env.settings().get("setting"));
+    }
+
+    public void testDefaultPropertiesOverride() throws Exception {
+        Path configDir = homeDir.resolve("config");
+        Files.createDirectories(configDir);
+        Files.write(configDir.resolve("elasticsearch.yml"), Collections.singletonList("setting: bar"), StandardCharsets.UTF_8);
+        Map<String, String> props = Collections.singletonMap("default.setting", "foo");
+        Environment env = InternalSettingsPreparer.prepareEnvironment(baseEnvSettings, null, props);
+        assertEquals("bar", env.settings().get("setting"));
+    }
 }