Class Plugin

All Implemented Interfaces:
Closeable, AutoCloseable

public abstract class Plugin extends Object implements Closeable
An extension point allowing to plug in custom functionality. This class has a number of extension points that are available to all plugins, in addition you can implement any of the following interfaces to further customize Elasticsearch:
  • Constructor Details

    • Plugin

      public Plugin()
  • Method Details

    • getFeature

      protected Optional<String> getFeature()
      A feature exposed by the plugin. This should be used if a plugin exposes ClusterState.Custom or Metadata.Custom; see also ClusterState.FeatureAware.
      a feature set represented by this plugin, or the empty optional if the plugin does not expose cluster state or metadata customs
    • createGuiceModules

      public Collection<Module> createGuiceModules()
      Node level guice modules.
    • getGuiceServiceClasses

      public Collection<Class<? extends LifecycleComponent>> getGuiceServiceClasses()
      Node level services that will be automatically started/stopped/closed. This classes must be constructed by injection with guice.
    • createComponents

      public Collection<Object> createComponents(Client client, ClusterService clusterService, ThreadPool threadPool, ResourceWatcherService resourceWatcherService, ScriptService scriptService, NamedXContentRegistry xContentRegistry, Environment environment, NodeEnvironment nodeEnvironment, NamedWriteableRegistry namedWriteableRegistry, IndexNameExpressionResolver indexNameExpressionResolver, Supplier<RepositoriesService> repositoriesServiceSupplier)
      Returns components added by this plugin. Any components returned that implement LifecycleComponent will have their lifecycle managed. Note: To aid in the migration away from guice, all objects returned as components will be bound in guice to themselves.
      client - A client to make requests to the system
      clusterService - A service to allow watching and updating cluster state
      threadPool - A service to allow retrieving an executor to run an async action
      resourceWatcherService - A service to watch for changes to node local files
      scriptService - A service to allow running scripts on the local node
      xContentRegistry - the registry for extensible xContent parsing
      environment - the environment for path and setting configurations
      nodeEnvironment - the node environment used coordinate access to the data paths
      namedWriteableRegistry - the registry for NamedWriteable object parsing
      indexNameExpressionResolver - A service that resolves expression to index and alias names
      repositoriesServiceSupplier - A supplier for the service that manages snapshot repositories; will return null when this method is called, but will return the repositories service once the node is initialized.
    • additionalSettings

      public Settings additionalSettings()
      Additional node settings loaded by the plugin. Note that settings that are explicit in the nodes settings can't be overwritten with the additional settings. These settings added if they don't exist.
    • getNamedWriteables

      public List<NamedWriteableRegistry.Entry> getNamedWriteables()
      Returns parsers for NamedWriteable this plugin will use over the transport protocol.
      See Also:
    • getNamedXContent

      public List<NamedXContentRegistry.Entry> getNamedXContent()
      Returns parsers for named objects this plugin will parse from XContentParser.namedObject(Class, String, Object).
      See Also:
    • onIndexModule

      public void onIndexModule(IndexModule indexModule)
      Called before a new index is created on a node. The given module can be used to register index-level extensions.
    • getSettings

      public List<Setting<?>> getSettings()
      Returns a list of additional Setting definitions for this plugin.
    • getSettingsFilter

      public List<String> getSettingsFilter()
      Returns a list of additional settings filter for this plugin
    • getSettingUpgraders

      public List<SettingUpgrader<?>> getSettingUpgraders()
      Get the setting upgraders provided by this plugin.
      the settings upgraders
    • getIndexTemplateMetadataUpgrader

      public UnaryOperator<Map<String,IndexTemplateMetadata>> getIndexTemplateMetadataUpgrader()
      Provides a function to modify index template meta data on startup.

      Plugins should return the input template map via UnaryOperator.identity() if no upgrade is required.

      The order of the template upgrader calls is undefined and can change between runs so, it is expected that plugins will modify only templates owned by them to avoid conflicts.

      Never null. The same or upgraded IndexTemplateMetadata map.
      IllegalStateException - if the node should not start because at least one IndexTemplateMetadata cannot be upgraded
    • getExecutorBuilders

      public List<ExecutorBuilder<?>> getExecutorBuilders(Settings settings)
      Provides the list of this plugin's custom thread pools, empty if none.
      settings - the current settings
      executors builders for this plugin's custom thread pools
    • getBootstrapChecks

      public List<BootstrapCheck> getBootstrapChecks()
      Returns a list of checks that are enforced when a node starts up once a node has the transport protocol bound to a non-loopback interface. In this case we assume the node is running in production and all bootstrap checks must pass. This allows plugins to provide a better out of the box experience by pre-configuring otherwise (in production) mandatory settings or to enforce certain configurations like OS settings or 3rd party resources.
    • getRoles

      public Set<DiscoveryNodeRole> getRoles()
    • close

      public void close() throws IOException
      Close the resources opened by this plugin.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      IOException - if the plugin failed to close its resources
    • getAdditionalIndexSettingProviders

      public Collection<IndexSettingProvider> getAdditionalIndexSettingProviders()
      An IndexSettingProvider allows hooking in to parts of an index lifecycle to provide explicit default settings for newly created indices. Rather than changing the default values for an index-level setting, these act as though the setting has been set explicitly, but still allow the setting to be overridden by a template or creation request body.