Refactor Alerter plugins feature. (azkaban#3217)

jackwillfly3235 · Jan 3, 2023 · f627f96 · f627f96
1 parent bfd36e2
commit f627f96
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Showing 8 changed files with 191 additions and 214 deletions.
diff --git a/azkaban-common/src/main/java/azkaban/executor/AlerterHolder.java b/azkaban-common/src/main/java/azkaban/executor/AlerterHolder.java
@@ -16,119 +16,118 @@
 package azkaban.executor;
 
 import azkaban.alert.Alerter;
+import azkaban.spi.AzkabanException;
 import azkaban.utils.Emailer;
 import azkaban.utils.FileIOUtils;
 import azkaban.utils.PluginUtils;
 import azkaban.utils.Props;
 import azkaban.utils.PropsUtils;
-import javax.inject.Inject;
-import javax.inject.Singleton;
 import java.io.File;
 import java.lang.reflect.Constructor;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.apache.log4j.Logger;
-
+import java.util.function.BiConsumer;
+import javax.inject.Inject;
+import javax.inject.Singleton;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 @Singleton
 public class AlerterHolder {
 
- private static final Logger logger = Logger.getLogger(AlerterHolder.class);
- private Map<String, Alerter> alerters;
+ private static final Logger logger = LoggerFactory.getLogger(AlerterHolder.class);
+ private final Map<String, Alerter> alerters;
 
  @Inject
  public AlerterHolder(final Props props, final Emailer mailAlerter) {
- try {
- this.alerters = loadAlerters(props, mailAlerter);
- } catch (final Exception ex) {
- logger.error(ex);
- this.alerters = new HashMap<>();
- }
- }
-
- private Map<String, Alerter> loadAlerters(final Props props, final Emailer mailAlerter) {
  final Map<String, Alerter> allAlerters = new HashMap<>();
- // load built-in alerters
+ // Load built-in alerters.
  allAlerters.put("email", mailAlerter);
- // load all plugin alerters
- final String pluginDir = props.getString("alerter.plugin.dir", "plugins/alerter");
- allAlerters.putAll(loadPluginAlerters(pluginDir));
- return allAlerters;
+ // Load additional alerter plugins if any.
+ final String customAlertersBaseDir = props.getString("alerter.plugin.dir", "plugins/alerter");
+ allAlerters.putAll(loadCustomAlerters(customAlertersBaseDir));
+ this.alerters = allAlerters;
+ logger.info("Alerter plugins loaded: {}", this.alerters.keySet());
  }
 
- private Map<String, Alerter> loadPluginAlerters(final String pluginPath) {
- final File alerterPluginPath = new File(pluginPath);
- if (!alerterPluginPath.exists()) {
+ private Map<String, Alerter> loadCustomAlerters(final String alerterPluginsRootPath) {
+ final File pluginsRootPath = new File(alerterPluginsRootPath);
+ if (!pluginsRootPath.exists()) {
  return Collections.<String, Alerter>emptyMap();
  }
 
  final Map<String, Alerter> installedAlerterPlugins = new HashMap<>();
  final ClassLoader parentLoader = getClass().getClassLoader();
- final File[] pluginDirs = alerterPluginPath.listFiles();
- final ArrayList<String> jarPaths = new ArrayList<>();
+ final File[] pluginDirs = pluginsRootPath.listFiles();
 
  for (final File pluginDir : pluginDirs) {
- // load plugin properties
- final Props pluginProps = PropsUtils.loadPluginProps(pluginDir);
- if (pluginProps == null) {
- continue;
- }
-
- final String pluginName = pluginProps.getString("alerter.name");
- final List<String> extLibClassPaths =
- pluginProps.getStringList("alerter.external.classpaths",
- (List<String>) null);
-
- final String pluginClass = pluginProps.getString("alerter.class");
- if (pluginClass == null) {
- logger.error("Alerter class is not set.");
- continue;
- } else {
- logger.info("Plugin class " + pluginClass);
+ try {
+ loadCustomAlerter(installedAlerterPlugins, parentLoader, pluginDir);
+ } catch (final Exception e) {
+ logger.error(String.format("Failed to load alerter plugin in '%s'.", pluginDir), e);
  }
+ }
+ return installedAlerterPlugins;
+ }
 
- Class<?> alerterClass =
- PluginUtils.getPluginClass(pluginClass, pluginDir, extLibClassPaths, parentLoader);
+ private void loadCustomAlerter(final Map<String, Alerter> installedAlerterPlugins,
+ final ClassLoader parentLoader, final File pluginDir) {
+ // Load plugin properties.
+ final Props pluginProps = PropsUtils.loadPluginProps(pluginDir);
+ if (pluginProps == null) {
+ throw new AzkabanException("Plugin config properties could not be loaded.");
+ }
 
- if (alerterClass == null) {
- continue;
- }
+ final String pluginName = pluginProps.getString("alerter.name", "").trim();
+ if (pluginName.isEmpty()) {
+ throw new AzkabanException("Alerter name is required.");
+ }
 
- final String source = FileIOUtils.getSourcePathFromClass(alerterClass);
- logger.info("Source jar " + source);
- jarPaths.add("jar:file:" + source);
+ final List<String> extLibClassPaths = pluginProps.getStringList(
+ "alerter.external.classpaths", (List<String>) null);
 
- Constructor<?> constructor = null;
- try {
- constructor = alerterClass.getConstructor(Props.class);
- } catch (final NoSuchMethodException e) {
- logger.error("Constructor not found in " + pluginClass);
- continue;
- }
+ final String pluginClass = pluginProps.getString("alerter.class", "").trim();
+ if (pluginClass.isEmpty()) {
+ throw new AzkabanException("Alerter class is required.");
+ }
 
- Object obj = null;
- try {
- obj = constructor.newInstance(pluginProps);
- } catch (final Exception e) {
- logger.error(e);
- }
+ final Class<?> alerterClass =
+ PluginUtils.getPluginClass(pluginClass, pluginDir, extLibClassPaths, parentLoader);
+ if (alerterClass == null) {
+ throw new AzkabanException(
+ String.format("Alerter class '%s' could not be loaded.", pluginClass));
+ }
+ logger.info("Loaded alerter class '{}' from '{}'.", pluginClass,
+ FileIOUtils.getSourcePathFromClass(alerterClass));
 
- if (!(obj instanceof Alerter)) {
- logger.error("The object is not an Alerter");
- continue;
- }
+ Constructor<?> constructor = null;
+ try {
+ constructor = alerterClass.getConstructor(Props.class);
+ } catch (final NoSuchMethodException e) {
+ throw new AzkabanException("Alerter class constructor wasn't found.", e);
+ }
 
- final Alerter plugin = (Alerter) obj;
- installedAlerterPlugins.put(pluginName, plugin);
+ final Object obj;
+ try {
+ obj = constructor.newInstance(pluginProps);
+ } catch (final Exception e) {
+ throw new AzkabanException(String.format("Alerter class '%s' could not be instantiated.",
+ pluginClass), e);
  }
 
- return installedAlerterPlugins;
+ if (!(obj instanceof Alerter)) {
+ throw new AzkabanException("Instantiated object is not an Alerter.");
+ }
+ installedAlerterPlugins.put(pluginName, (Alerter) obj);
  }
 
  public Alerter get(final String alerterType) {
  return this.alerters.get(alerterType);
  }
+
+ public void forEach(final BiConsumer<String, Alerter> consumer) {
+ this.alerters.forEach(consumer);
+ }
 }