Elasticsearch Apps
What is Elasticsearch Apps?
Elasticsearch Apps is a tool for instrumenting the Maven artifact dependency mechanism for downloding and resolving Elasticsearch plugins and their dependencies.
It extends the PluginManager, the PluginService and the PluginsModule classes in org.elasticsearch.plugins. Existing Elasticsearch plugins, which are offered as zip file downloads, can be used without modification.
The tool bin/apps is aimed to replace bin/plugins. It works similar, but uses the JBoss ShrinkWrap resolver project to handle with Maven artifacts in remote repositories.
The config file config/elasticsearch.yml is enriched by additional entries for declaring the Elasticsearch apps.
Apps are divided into three groups:
- plugin apps, downloaded as a zip file from an URL
- site apps, downloaded as a zip file from an URL
- Maven artifact apps, with dependencies
How to use
This Apps github project elasticsearch-apps embeds Elasticsearch 0.20.1 for demonstration purpose.
Implementing the new AppService required to override some Elasticsearch classes. Therefore, in the bin/apps shell script, a special classpath is set up to ensure this.
By unpacking the elasticseach-apps project, you can install it by the command
mvn clean install
Some tests are run that already show how the Maven-based artifact management works.
Now, you can tweak with the configurations in the config folder and try things out.
To get integrated into the mainline, elasticsearch-apps will have to be converted to a pull request.
How to set it up
For the Maven part, there is a new configuration file config/apps.xml which is equivalent to the Maven settings.xml. In this file, Maven repositories for Elasticsearch can be configured.
This is a verbose sample of a config/apps.xml which just activates the Maven central repo where the Elasticsearch core plugins already live.
<?xml version="1.0" encoding="UTF-8"?>
<!-- see http://maven.apache.org/settings.html -->
<settings>
<!-- if you want your Maven local repo equal to Elasticsearch apps local repo -->
<!-- <localRepository>file://${user.home}/.m2/repository</localRepository> -->
<!-- Elasticsearch apps local repo-->
<localRepository>plugins/repository</localRepository>
<!-- set offline to true to disable any network access when accessing repos. Default is false. -->
<!-- <offline>true</offline> -->
<profiles>
<!--
The default active profile. Add your remote Maven repositories here.
-->
<profile>
<id>apps</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<repositories>
<repository>
<id>central</id>
<name>Maven Repository</name>
<url>http://repo1.maven.org/maven2</url>
<layout>default</layout>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
</profile>
</profiles>
</settings>
Now the Maven resolver is ready.
Adding your plugin declarations to Elasticsearch configuration
You can add the plugins you want to declare to be installed by adding some lines to config/elasticsearch.yml.
This short example declares the icu plugin with a given version:
apps.dependencies.analysis-icu.dependency: org.elasticsearch:elasticsearch-analysis-icu:1.7.0
This longer example declares the head plugin as a zip download, and a mandatory analysis-icu plugin, where all versions from 1.0.0 until the current version are valid:
########################### Apps #############################################
apps:
mandatory:
org.elasticsearch:elasticsearch-analysis-icu
sites:
elasticsearch-head:
url: https://github.com/mobz/elasticsearch-head/archive/master.zip
enabled: true
excludes: [
"org.elasticsearch:elasticsearch",
"log4j:log4j"
]
dependencies:
analysis-icu:
dependency: org.elasticsearch:elasticsearch-analysis-icu:[1.0.0,)
enabled: true
That's it. Now, by just starting up an Elasticsearch node, the declared apps are automatically downloaded from remote repository sites and activated.
The command for executing a node in the foreground is
bin/elasticsearch -f
The bin/apps tool
It is often convenient to investigate for the latest versions of plugins, or looking up what plugins exist without starting a node. The bin/apps tool is a standalone version of the app service. It's purpose is to offer convenient services to manage plugin apps as a "one stop shop".
You can control the plugin resolving and installation with this tool.
When starting bin/apps, it reads the configuration files, and begins with the download and artifact resolution process, and then opens a console.
Here is a quick overview of the artifact-related commands:
ls - shows a list of the installed Elasticsearch artifact apps, site plugin apps, and legacy plugins
resolve <artifact> - show all dependencies of the artifact, where the artifact is given in Maven canonical form
install <artifact> - creates an artifact app out of a dependency by looking for es-plugin.properties on the classpath and instantiating the plugin class
remove <artifact> - removes an artifact from the local app repository
tree <artifact> - shows all the dependencies of the given artifact as a tree
whatrequires <artifact> - for a given Maven artifact, show all Elasticsearch apps that depend on it (work in progress)
More commands to follow.
Under development
The Elasticsearch apps effort is currently under development.
For the iterations already done with logfile dumps and info, see
Iteration 1 - a console-based app tool
Iteration 2 - version resolution and new URI classloader
Iteration 3 - downloading and installing all Elasticsearch core plugins automatically
License
Elasticsearch Apps
Copyright (C) 2012 Jörg Prante
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent