[SMALLFIX] Track source for alluxio-site.properties loaded from class…

…path (#7473)

* Track source for alluxio-site.properties loaded from classpath

* Add test

* Address comments

core/common/src/main/java/alluxio/Configuration.java

@@ -18,6 +18,7 @@
 
 import com.google.common.base.Preconditions;
 
+import java.net.URL;
 import java.time.Duration;
 import java.util.List;
 import java.util.Map;
@@ -84,7 +85,11 @@ public static void reset() {
     if (sitePropertyFile != null) {
       siteProps = ConfigurationUtils.loadPropertiesFromFile(sitePropertyFile);
     } else {
-      siteProps = ConfigurationUtils.loadPropertiesFromResource(Constants.SITE_PROPERTIES);
+      URL resource = Configuration.class.getClassLoader().getResource(Constants.SITE_PROPERTIES);
+      siteProps = ConfigurationUtils.loadPropertiesFromResource(resource);
+      if (siteProps != null) {
+        sitePropertyFile = resource.getPath();
+      }
     }
     PROPERTIES.merge(siteProps, Source.siteProperty(sitePropertyFile));
     validate();

core/common/src/main/java/alluxio/conf/Source.java

@@ -11,6 +11,8 @@
 
 package alluxio.conf;
 
+import com.google.common.base.Objects;
+
 /**
  * The source of a configuration property.
  */
@@ -93,6 +95,23 @@ private SitePropertySource(String filename) {
       mFilename = filename;
     }
 
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) {
+        return true;
+      }
+      if (!(o instanceof SitePropertySource)) {
+        return false;
+      }
+      SitePropertySource that = (SitePropertySource) o;
+      return Objects.equal(mFilename, that.mFilename);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hashCode(mFilename);
+    }
+
     @Override
     public String toString() {
       return String.format("%s (%s)", mType, mFilename);

core/common/src/main/java/alluxio/util/ConfigurationUtils.java

@@ -27,6 +27,7 @@
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URL;
 import java.util.List;
 import java.util.Properties;
 
@@ -41,48 +42,50 @@ public final class ConfigurationUtils {
   private ConfigurationUtils() {} // prevent instantiation
 
   /**
-   * Loads properties from resource. This method will search Classpath for the properties file with
-   * the given resourceName.
+   * Loads properties from a resource.
    *
-   * @param resourceName filename of the properties file
+   * @param resource url of the properties file
    * @return a set of properties on success, or null if failed
    */
-  public static Properties loadPropertiesFromResource(String resourceName) {
-    Properties properties = new Properties();
-
-    InputStream inputStream =
-        Configuration.class.getClassLoader().getResourceAsStream(resourceName);
-    if (inputStream == null) {
-      return null;
-    }
-
+  @Nullable
+  public static Properties loadPropertiesFromResource(URL resource) {
     try {
-      properties.load(inputStream);
+      return loadProperties(resource.openStream());
     } catch (IOException e) {
-      LOG.warn("Unable to load default Alluxio properties file {} : {}", resourceName,
-          e.getMessage());
+      LOG.warn("Failed to read properties from {}: {}", resource, e.toString());
       return null;
     }
-    return properties;
   }
 
   /**
-   * Loads properties from the given file. This method will search Classpath for the properties
-   * file.
+   * Loads properties from the given file.
    *
    * @param filePath the absolute path of the file to load properties
    * @return a set of properties on success, or null if failed
    */
   @Nullable
   public static Properties loadPropertiesFromFile(String filePath) {
-    Properties properties = new Properties();
-
     try (FileInputStream fileInputStream = new FileInputStream(filePath)) {
-      properties.load(fileInputStream);
+      return loadProperties(fileInputStream);
     } catch (FileNotFoundException e) {
       return null;
     } catch (IOException e) {
-      LOG.warn("Unable to load properties file {} : {}", filePath, e.getMessage());
+      LOG.warn("Failed to close property input stream from {}: {}", filePath, e.toString());
+      return null;
+    }
+  }
+
+  /**
+   * @param stream the stream to read properties from
+   * @return a properties object populated from the stream
+   */
+  @Nullable
+  public static Properties loadProperties(InputStream stream) {
+    Properties properties = new Properties();
+    try {
+      properties.load(stream);
+    } catch (IOException e) {
+      LOG.warn("Unable to load properties: {}", e.toString());
       return null;
     }
     return properties;

core/common/src/test/java/alluxio/ConfigurationTest.java

@@ -28,10 +28,13 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
+import org.powermock.reflect.Whitebox;
 
+import java.io.BufferedWriter;
 import java.io.Closeable;
 import java.io.File;
 import java.io.FileOutputStream;
+import java.nio.file.Files;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
@@ -865,4 +868,22 @@ public void extensionProperty() {
     assertEquals("value", Configuration.get(fakeExtensionKey));
     assertTrue(PropertyKey.fromString(fakeKeyName).isBuiltIn());
   }
+
+  @Test
+  public void findPropertiesFileClasspath() throws Exception {
+    try (Closeable p =
+        new SystemPropertyRule(PropertyKey.TEST_MODE.toString(), "false").toResource()) {
+      File dir = AlluxioTestDirectory.createTemporaryDirectory("findPropertiesFileClasspath");
+      Whitebox.invokeMethod(ClassLoader.getSystemClassLoader(), "addURL", dir.toURI().toURL());
+      File props = new File(dir, "alluxio-site.properties");
+      try (BufferedWriter writer = Files.newBufferedWriter(props.toPath())) {
+        writer.write(String.format("%s=%s", PropertyKey.MASTER_HOSTNAME, "test_hostname"));
+      }
+      Configuration.reset();
+      assertEquals("test_hostname", Configuration.get(PropertyKey.MASTER_HOSTNAME));
+      assertEquals(Source.siteProperty(props.getPath()),
+          Configuration.getSource(PropertyKey.MASTER_HOSTNAME));
+      props.delete();
+    }
+  }
 }