Logstash
Logstash is part of the Elastic Stack along with Beats, Elasticsearch and Kibana. Logstash is a server-side data processing pipeline that ingests data from a multitude of sources simultaneously, transforms it, and then sends it to your favorite "stash." (Ours is Elasticsearch, naturally.). Logstash has over 200 plugins, and you can write your own very easily as well.
For more info, see https://www.elastic.co/products/logstash
Documentation and Getting Started
You can find the documentation and getting started guides for Logstash on the elastic.co site
For information about building the documentation, see the README in https://github.com/elastic/docs
Downloads
You can download officially released Logstash binaries, as well as debian/rpm packages for the supported platforms, from downloads page.
Need Help?
- Logstash Forum
- Logstash Documentation
- #logstash on freenode IRC
- Logstash Product Information
- Elastic Support
Logstash Plugins
Logstash plugins are hosted in separate repositories under the logstash-plugins github organization. Each plugin is a self-contained Ruby gem which gets published to RubyGems.org.
Writing your own Plugin
Logstash is known for its extensibility. There are hundreds of plugins for Logstash and you can write your own very easily! For more info on developing and testing these plugins, please see the working with plugins section
Plugin Issues and Pull Requests
Please open new issues and pull requests for plugins under its own repository
For example, if you have to report an issue/enhancement for the Elasticsearch output, please do so here.
Logstash core will continue to exist under this repository and all related issues and pull requests can be submitted here.
Developing Logstash Core
Prerequisites
- Install JDK version 11 or 17. Make sure to set the
JAVA_HOME
environment variable to the path to your JDK installation directory. For exampleset JAVA_HOME=<JDK_PATH>
- Install JRuby 9.2.x It is recommended to use a Ruby version manager such as RVM or rbenv.
- Install
rake
andbundler
tool usinggem install rake
andgem install bundler
respectively.
RVM install (optional)
If you prefer to use rvm (ruby version manager) to manage Ruby versions on your machine, follow these directions. In the Logstash folder:
gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
\curl -sSL https://get.rvm.io | bash -s stable --ruby=$(cat .ruby-version)
Check Ruby version
Before you proceed, please check your ruby version by:
$ ruby -v
The printed version should be the same as in the .ruby-version
file.
Building Logstash
The Logstash project includes the source code for all of Logstash, including the Elastic-Licensed X-Pack features and functions; to run Logstash from source using only the OSS-licensed code, export the OSS
environment variable with a value of true
:
export OSS=true
- Set up the location of the source code to build
export LOGSTASH_SOURCE=1
export LOGSTASH_PATH=/YOUR/LOGSTASH/DIRECTORY
Install dependencies with gradle
(recommended)1
- Install development dependencies
./gradlew installDevelopmentGems
- Install default plugins and other dependencies
./gradlew installDefaultGems
Verify the installation
To verify your environment, run the following to start Logstash and send your first event:
bin/logstash -e 'input { stdin { } } output { stdout {} }'
This should start Logstash with stdin input waiting for you to enter an event
hello world
2016-11-11T01:22:14.405+0000 0.0.0.0 hello world
Advanced: Drip Launcher
Drip is a tool that solves the slow JVM startup problem while developing Logstash. The drip script is intended to be a drop-in replacement for the java command. We recommend using drip during development, in particular for running tests. Using drip, the first invocation of a command will not be faster but the subsequent commands will be swift.
To tell logstash to use drip, set the environment variable JAVACMD=`which drip`
.
Example (but see the Testing section below before running rspec for the first time):
JAVACMD=`which drip` bin/rspec
Caveats
Drip does not work with STDIN. You cannot use drip for running configs which use the stdin plugin.
Building Logstash Documentation
To build the Logstash Reference (open source content only) on your local machine, clone the following repos:
logstash - contains main docs about core features
logstash-docs - contains generated plugin docs
docs - contains doc build files
Make sure you have the same branch checked out in logstash
and logstash-docs
.
Check out master
in the docs
repo.
Run the doc build script from within the docs
repo. For example:
./build_docs.pl --doc ../logstash/docs/index.asciidoc --chunk=1 -open
Testing
Most of the unit tests in Logstash are written using rspec for the Ruby parts. For the Java parts, we use junit. For testing you can use the test rake
tasks and the bin/rspec
command, see instructions below:
Core tests
1- To run the core tests you can use the Gradle task:
./gradlew test
or use the rspec
tool to run all tests or run a specific test:
bin/rspec
bin/rspec spec/foo/bar_spec.rb
Note that before running the rspec
command for the first time you need to set up the RSpec test dependencies by running:
./gradlew bootstrap
2- To run the subset of tests covering the Java codebase only run:
./gradlew javaTests
3- To execute the complete test-suite including the integration tests run:
./gradlew check
4- To execute a single Ruby test run:
SPEC_OPTS="-fd -P logstash-core/spec/logstash/api/commands/default_metadata_spec.rb" ./gradlew :logstash-core:rubyTests --tests org.logstash.RSpecTests
5- To execute single spec for integration test, run:
./gradlew integrationTests -PrubyIntegrationSpecs=specs/slowlog_spec.rb
Sometimes you might find a change to a piece of Logstash code causes a test to hang. These can be hard to debug.
If you set LS_JAVA_OPTS="-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005"
you can connect to a running Logstash with your IDEs debugger which can be a great way of finding the issue.
Plugins tests
To run the tests of all currently installed plugins:
rake test:plugins
You can install the default set of plugins included in the logstash package:
rake test:install-default
Note that if a plugin is installed using the plugin manager bin/logstash-plugin install ...
do not forget to also install the plugins development dependencies using the following command after the plugin installation:
bin/logstash-plugin install --development
Building Artifacts
Built artifacts will be placed in the LS_HOME/build
directory, and will create the directory if it is not already present.
You can build a Logstash snapshot package as tarball or zip file
./gradlew assembleTarDistribution
./gradlew assembleZipDistribution
OSS-only artifacts can similarly be built with their own gradle tasks:
./gradlew assembleOssTarDistribution
./gradlew assembleOssZipDistribution
You can also build .rpm and .deb, but the fpm tool is required.
rake artifact:rpm
rake artifact:deb
and:
rake artifact:rpm_oss
rake artifact:deb_oss
Using a Custom JRuby Distribution
If you want the build to use a custom JRuby you can do so by setting a path to a custom
JRuby distribution's source root via the custom.jruby.path
Gradle property.
E.g.
./gradlew clean test -Pcustom.jruby.path="/path/to/jruby"
Project Principles
- Community: If a newbie has a bad time, it's a bug.
- Software: Make it work, then make it right, then make it fast.
- Technology: If it doesn't do a thing today, we can make it do it tomorrow.
Contributing
All contributions are welcome: ideas, patches, documentation, bug reports, complaints, and even something you drew up on a napkin.
Programming is not a required skill. Whatever you've seen about open source and maintainers or community members saying "send patches or die" - you will not see that here.
It is more important that you are able to contribute.
For more information about contributing, see the CONTRIBUTING file.
Footnotes
Footnotes
-
Use bundle instead of gradle to install dependencies Alternatively, instead of using
gradle
you can also usebundle
:-
Install development dependencies
bundle config set --local path vendor/bundle bundle install
-
Bootstrap the environment:
rake bootstrap
-
You can then use
bin/logstash
to start Logstash, but there are no plugins installed. To install default plugins, you can run:rake plugin:install-default
This will install the 80+ default plugins which makes Logstash ready to connect to multiple data sources, perform transformations and send the results to Elasticsearch and other destinations.
↩ -