Ignore properties files in hidden directories

This commit modifies the logic for finding properties files using
wildcard paths to ignore files if any part of the file path contains
a hidden directory. Hidden directories are common when Kubernetes
mounts config maps onto volumes in a pod, which was causing the same
properties files to be loaded multiple times.

Fixes gh-23160

Author: scottfrederick

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/config/ConfigFileApplicationListener.java

@@ -18,6 +18,8 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -108,6 +110,7 @@
  * @author Andy Wilkinson
  * @author Eddú Meléndez
  * @author Madhura Bhave
+ * @author Scott Frederick
  * @since 1.0.0
  */
 public class ConfigFileApplicationListener implements EnvironmentPostProcessor, SmartApplicationListener, Ordered {
@@ -519,6 +522,14 @@ private void load(PropertySourceLoader loader, String location, Profile profile,
 						}
 						continue;
 					}
+					if (resource.isFile() && hasHiddenPathElement(resource)) {
+						if (this.logger.isTraceEnabled()) {
+							StringBuilder description = getDescription("Skipped location with hidden path element ",
+									location, resource, profile);
+							this.logger.trace(description);
+						}
+						continue;
+					}
 					String name = "applicationConfig: [" + getLocationName(location, resource) + "]";
 					List<Document> documents = loadDocuments(loader, name, resource);
 					if (CollectionUtils.isEmpty(documents)) {
@@ -555,6 +566,16 @@ private void load(PropertySourceLoader loader, String location, Profile profile,
 			}
 		}
 
+		private boolean hasHiddenPathElement(Resource resource) throws IOException {
+			String cleanPath = StringUtils.cleanPath(resource.getFile().getAbsolutePath());
+			for (Path value : Paths.get(cleanPath)) {
+				if (value.toString().startsWith(".")) {
+					return true;
+				}
+			}
+			return false;
+		}
+
 		private String getLocationName(String location, Resource resource) {
 			if (!location.contains("*")) {
 				return location;

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/config/ConfigFileApplicationListenerTests.java

@@ -75,6 +75,7 @@
  * @author Dave Syer
  * @author Eddú Meléndez
  * @author Madhura Bhave
+ * @author Scott Frederick
  */
 @ExtendWith(OutputCaptureExtension.class)
 class ConfigFileApplicationListenerTests {
@@ -1080,6 +1081,16 @@ void locationsWithWildcardDirectoriesShouldRestrictToOneLevelDeep() {
 		assertThat(this.environment.getProperty("third.property")).isNull();
 	}
 
+	@Test
+	void locationsWithWildcardDirectoriesShouldIgnoreHiddenDirectories() {
+		String location = "file:src/test/resources/config/*/";
+		TestPropertySourceUtils.addInlinedPropertiesToEnvironment(this.environment,
+				"spring.config.location=" + location);
+		this.initializer.setSearchNames("testproperties");
+		this.initializer.postProcessEnvironment(this.environment, this.application);
+		assertThat(this.environment.getProperty("fourth.property")).isNull();
+	}
+
 	@Test
 	void locationsWithWildcardDirectoriesShouldLoadAllFilesThatMatch() {
 		String location = "file:src/test/resources/config/*/";
@@ -1124,6 +1135,16 @@ void locationsWithWildcardFilesShouldLoadAllFilesThatMatch() {
 		assertThat(second).isEqualTo("ball");
 	}
 
+	@Test
+	void locationsWithWildcardFilesShouldIgnoreHiddenDirectories() {
+		String location = "file:src/test/resources/config/*/testproperties.properties";
+		TestPropertySourceUtils.addInlinedPropertiesToEnvironment(this.environment,
+				"spring.config.location=" + location);
+		this.initializer.setSearchNames("testproperties");
+		this.initializer.postProcessEnvironment(this.environment, this.application);
+		assertThat(this.environment.getProperty("fourth.property")).isNull();
+	}
+
 	private Condition<ConfigurableEnvironment> matchingPropertySource(final String sourceName) {
 		return new Condition<ConfigurableEnvironment>("environment containing property source " + sourceName) {
 

spring-boot-project/spring-boot/src/test/resources/config/.hidden/testproperties.properties

@@ -0,0 +1 @@
+fourth.property=shouldbehidden