/elk-docker

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Elastic stack (ELK) on Docker

Elastic Stack version Build Status Join the chat at https://gitter.im/deviantony/docker-elk

Run the version 7.x of the Elastic stack with Docker and Docker Compose.

It gives you the ability to analyze any data set by using the searching/aggregation capabilities of Elasticsearch and the visualization power of Kibana.

Animated demo

Note
The Docker images backing this stack include X-Pack with paid features enabled by default (see How to disable paid features to disable them). The trial license is valid for 30 days. After this license expires, you can continue using the free features seamlessly, without losing any data.

Based on the official Docker images from Elastic:

Other available stack variants:

  • tls: TLS encryption enabled in Elasticsearch
  • searchguard: Search Guard support

Philosophy

We aim at providing the simplest possible entry into the Elastic stack for anybody who feels like experimenting with this powerful combo of technologies. This project's default configuration is purposely minimal and unopinionated. It does not rely on any external dependency, and uses as little custom automation as necessary to get things up and running.

Instead, we believe in good documentation so that you can use this repository as a template, tweak it, and make it your own. sherifabdlnaby/elastdocker is one example among others of project that builds upon this idea.

Contents

  1. Requirements
  2. Usage
  3. Configuration
  4. Extensibility
  5. JVM tuning
  6. Going further

Requirements

Host setup

Warning
While Compose versions between 1.22.0 and 1.25.5 can technically run this stack as well, these versions have a known issue which prevents them from parsing quoted values properly inside .env files.

Note
Especially on Linux, make sure your user has the required permissions to interact with the Docker daemon.

By default, the stack exposes the following ports:

  • 5044: Logstash Beats input
  • 5000: Logstash TCP input
  • 9600: Logstash monitoring API
  • 9200: Elasticsearch HTTP
  • 9300: Elasticsearch TCP transport
  • 5601: Kibana

Warning
Elasticsearch's bootstrap checks were purposely disabled to facilitate the setup of the Elastic stack in development environments. For production setups, we recommend users to set up their host according to the instructions from the Elasticsearch documentation: Important System Configuration.

Docker Desktop

Windows

If you are using the legacy Hyper-V mode of Docker Desktop for Windows, ensure File Sharing is enabled for the C: drive.

macOS

The default configuration of Docker Desktop for Mac allows mounting files from /Users/, /Volume/, /private/, /tmp and /var/folders exclusively. Make sure the repository is cloned in one of those locations or follow the instructions from the documentation to add more locations.

Usage

Warning
You must rebuild the stack images with docker-compose build whenever you switch branch or update the version of an already existing stack.

Bringing up the stack

Clone this repository onto the Docker host that will run the stack, then start the stack's services locally using Docker Compose:

$ docker-compose up

Note
You can also run all services in the background (detached mode) by appending the -d flag to the above command.

Give Kibana about a minute to initialize, then access the Kibana web UI by opening http://localhost:5601 in a web browser and use the following (default) credentials to log in:

  • user: elastic
  • password: changeme

Note
Upon the initial startup, the elastic, logstash_internal and kibana_system Elasticsearch users are intialized with the values of the passwords defined in the .env file ("changeme" by default). The first one is the built-in superuser, the other two are used by Kibana and Logstash respectively to communicate with Elasticsearch. This task is only performed during the initial startup of the stack. To change users' passwords after they have been initialized, please refer to the instructions in the next section.

Initial setup

Setting up user authentication

Note
Refer to Security settings in Elasticsearch to disable authentication.

The "changeme" password set by default for all aforementioned users is unsecure. For increased security, we will reset the passwords of all aforementioned Elasticsearch users to random secrets.

  1. Reset passwords for built-in users

    The command below resets the passwords of all 6 built-in users. Take note of them.

    $ docker-compose exec -T elasticsearch bin/elasticsearch-setup-passwords auto --batch

    The password of the logstash_internal user must be changed manually, either from Kibana's Stack Management > Users view, or using the procedure described at How to reset a password programmatically.

  2. Replace usernames and passwords in configuration files

    Replace the password of the elastic user inside the .env file with the password generated in the previous step. Its value isn't used by any core component, but extensions use it to connect to Elasticsearch.

    Note
    In case you don't plan on using any of the provided extensions, or prefer to create your own roles and users to authenticate these services, it is safe to remove the ELASTIC_PASSWORD entry from the .env file altogether after the stack has been initialized.

    Replace the password of the logstash_internal user inside the .env file with the password generated in the previous step. Its value is referenced inside the Logstash pipeline file (logstash/pipeline/logstash.conf).

    Replace the password of the kibana_system user inside the .env file with the password generated in the previous step. Its value is referenced inside the Kibana configuration file (kibana/config/kibana.yml).

    See the Configuration section below for more information about these configuration files.

  3. Restart Logstash and Kibana to re-connect to Elasticsearch using the new passwords

    $ docker-compose up -d logstash kibana

Note
Learn more about the security of the Elastic stack at Secure the Elastic Stack.

Injecting data

Open the Kibana web UI by opening http://localhost:5601 in a web browser and use the following credentials to log in:

  • user: elastic
  • password: <your generated elastic password>

Now that the stack is fully configured, you can go ahead and inject some log entries. The shipped Logstash configuration allows you to send content via TCP:

# Using BSD netcat (Debian, Ubuntu, MacOS system, ...)
$ cat /path/to/logfile.log | nc -q0 localhost 5000
# Using GNU netcat (CentOS, Fedora, MacOS Homebrew, ...)
$ cat /path/to/logfile.log | nc -c localhost 5000

You can also load the sample data provided by your Kibana installation.

Default Kibana index pattern creation

When Kibana launches for the first time, it is not configured with any index pattern.

Via the Kibana web UI

Note
You need to inject data into Logstash before being able to configure a Logstash index pattern via the Kibana web UI.

Navigate to the Discover view of Kibana from the left sidebar. You will be prompted to create an index pattern. Enter logstash-* to match Logstash indices then, on the next page, select @timestamp as the time filter field. Finally, click Create index pattern and return to the Discover view to inspect your log entries.

Refer to Connect Kibana with Elasticsearch and Creating an index pattern for detailed instructions about the index pattern configuration.

On the command line

Create an index pattern via the Kibana API:

$ curl -XPOST -D- 'http://localhost:5601/api/saved_objects/index-pattern' \
    -H 'Content-Type: application/json' \
    -H 'kbn-version: 7.17.4' \
    -u elastic:<your generated elastic password> \
    -d '{"attributes":{"title":"logstash-*","timeFieldName":"@timestamp"}}'

The created pattern will automatically be marked as the default index pattern as soon as the Kibana UI is opened for the first time.

Cleanup

Elasticsearch data is persisted inside a volume by default.

In order to entirely shutdown the stack and remove all persisted data, use the following Docker Compose command:

$ docker-compose down -v

Version selection

To use a different version of the core Elastic components, simply change the version number inside the .env file. If you are upgrading an existing stack, remember to rebuild all container images using the docker-compose build command.

Warning
Always pay attention to the official upgrade instructions for each individual component before performing a stack upgrade.

Configuration

Note
Configuration is not dynamically reloaded, you will need to restart individual components after any configuration change.

How to configure Elasticsearch

The Elasticsearch configuration is stored in elasticsearch/config/elasticsearch.yml.

You can also specify the options you want to override by setting environment variables inside the Compose file:

elasticsearch:

  environment:
    network.host: _non_loopback_
    cluster.name: my-cluster

Please refer to the following documentation page for more details about how to configure Elasticsearch inside Docker containers: Install Elasticsearch with Docker.

How to configure Kibana

The Kibana default configuration is stored in kibana/config/kibana.yml.

You can also specify the options you want to override by setting environment variables inside the Compose file:

kibana:

  environment:
    SERVER_NAME: kibana.example.org

Please refer to the following documentation page for more details about how to configure Kibana inside Docker containers: Install Kibana with Docker.

How to configure Logstash

The Logstash configuration is stored in logstash/config/logstash.yml.

You can also specify the options you want to override by setting environment variables inside the Compose file:

logstash:

  environment:
    LOG_LEVEL: debug

Please refer to the following documentation page for more details about how to configure Logstash inside Docker containers: Configuring Logstash for Docker.

How to disable paid features

Switch the value of Elasticsearch's xpack.license.self_generated.type setting from trial to basic (see License settings).

You can also cancel an ongoing trial before its expiry date — and thus revert to a basic license — either from the License Management panel of Kibana, or using Elasticsearch's Licensing APIs.

How to scale out the Elasticsearch cluster

Follow the instructions from the Wiki: Scaling out Elasticsearch

How to reset a password programmatically

If for any reason your are unable to use Kibana to change the password of your users (including built-in users), you can use the Elasticsearch API instead and achieve the same result.

In the example below, we reset the password of the elastic user (notice "/user/elastic" in the URL):

$ curl -XPOST -D- 'http://localhost:9200/_security/user/elastic/_password' \
    -H 'Content-Type: application/json' \
    -u elastic:<your current elastic password> \
    -d '{"password" : "<your new password>"}'

Extensibility

How to add plugins

To add plugins to any ELK component you have to:

  1. Add a RUN statement to the corresponding Dockerfile (eg. RUN logstash-plugin install logstash-filter-json)
  2. Add the associated plugin code configuration to the service configuration (eg. Logstash input/output)
  3. Rebuild the images using the docker-compose build command

How to enable the provided extensions

A few extensions are available inside the extensions directory. These extensions provide features which are not part of the standard Elastic stack, but can be used to enrich it with extra integrations.

The documentation for these extensions is provided inside each individual subdirectory, on a per-extension basis. Some of them require manual changes to the default ELK configuration.

JVM tuning

How to specify the amount of memory used by a service

The startup scripts for Elasticsearch and Logstash can append extra JVM options from the value of an environment variable, allowing the user to adjust the amount of memory that can be used by each component:

Service Environment variable
Elasticsearch ES_JAVA_OPTS
Logstash LS_JAVA_OPTS

To accomodate environments where memory is scarce (Docker Desktop for Mac has only 2 GB available by default), the Heap Size allocation is capped by default in the docker-compose.yml file to 512 MB for Elasticsearch and 256 MB for Logstash. If you want to override the default JVM configuration, edit the matching environment variable(s) in the docker-compose.yml file.

For example, to increase the maximum JVM Heap Size for Logstash:

logstash:

  environment:
    LS_JAVA_OPTS: -Xms1g -Xmx1g

When these options are not set:

  • Elasticsearch starts with a JVM Heap Size that is determined automatically.
  • Logstash starts with a fixed JVM Heap Size of 1 GB.

How to enable a remote JMX connection to a service

As for the Java Heap memory (see above), you can specify JVM options to enable JMX and map the JMX port on the Docker host.

Update the {ES,LS}_JAVA_OPTS environment variable with the following content (I've mapped the JMX service on the port 18080, you can change that). Do not forget to update the -Djava.rmi.server.hostname option with the IP address of your Docker host (replace DOCKER_HOST_IP):

logstash:

  environment:
    LS_JAVA_OPTS: -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.port=18080 -Dcom.sun.management.jmxremote.rmi.port=18080 -Djava.rmi.server.hostname=DOCKER_HOST_IP -Dcom.sun.management.jmxremote.local.only=false

Going further

Plugins and integrations

See the following Wiki pages: