Docker ELK stack

Derived from the Docker ELK repository, with modifications made. Most network access points into Elasticstash have been removed, and Kibana is secured with Nginx.

Run the latest version of the ELK (Elasticseach, Logstash, Kibana) stack with Docker and Docker-compose.

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

Based on the official images:

• elasticsearch
• logstash
• kibana
• nginx

Requirements

Setup

1. Install Docker.
2. Install Docker-compose.
3. Clone this repository

Usage

Start the ELK stack using docker-compose:

$ docker-compose up

You can also choose to run it in background (detached mode):

$ docker-compose up -d

Now that the stack is running, you'll want to inject logs in it. The shipped logstash config accepts syslog messages on port 42185, and JSON input on port 5000.

You can then access Kibana UI by hitting http://localhost:5601 with a web browser. You'll need to log in with (by default) admin/admin, and you can customize login permissions by editing ./nginx/htpasswd.users.

NOTE: You'll need to inject data into logstash before being able to create a logstash index in Kibana. Then all you should have to do is to hit the create button.

See: https://www.elastic.co/guide/en/kibana/current/setup.html#connect

You can also access:

• Sense: http://localhost:5601/app/sense

NOTE: In order to use Sense, you'll need to query the IP address associated to your network device instead of localhost.

By default, the stack exposes the following ports:

• 5000: Logstash JSON input
• 42185: Logstash SYSLOG input
• 5601: Kibana through nginx

WARNING: If you're using boot2docker, you must access it via the boot2docker IP address instead of localhost.

WARNING: If you're using Docker Toolbox, you must access it via the docker-machine IP address instead of localhost.

Configuration

NOTE: Configuration is not dynamically reloaded, you will need to restart the stack after any change in the configuration of a component.

How can I tune Kibana configuration?

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

How can I tune Logstash configuration?

The logstash configuration is stored in logstash/config/logstash.conf.

The folder logstash/config is mapped onto the container /etc/logstash/conf.d so you can create more than one file in that folder if you'd like to. However, you must be aware that config files will be read from the directory in alphabetical order.

How can I add/remove nginx users?

Use htpasswd to generate a new ./nginx/htpasswd.users to suit your needs.

How can I specify the amount of memory used by Logstash?

The Logstash container use the LS_HEAP_SIZE environment variable to determine how much memory should be associated to the JVM heap memory (defaults to 500m).

If you want to override the default configuration, add the LS_HEAP_SIZE environment variable to the container in the docker-compose.yml:

logstash:
  build: logstash/
  command: logstash -f /etc/logstash/conf.d/logstash.conf
  volumes:
    - ./logstash/config:/etc/logstash/conf.d
  ports:
    - "5000:5000"
  links:
    - elasticsearch
  environment:
    - LS_HEAP_SIZE=2048m

How can I add Logstash plugins?

To add plugins to logstash you have to:

1. Add a RUN statement to the logstash/Dockerfile (ex. RUN logstash-plugin install logstash-filter-json)
2. Add the associated plugin code configuration to the logstash/config/logstash.conf file

How can I enable a remote JMX connection to Logstash?

As for the Java heap memory, another environment variable allows to specify JAVA_OPTS used by Logstash. You'll need to specify the appropriate options to enable JMX and map the JMX port on the docker host.

Update the container in the docker-compose.yml to add the 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:
  build: logstash/
  command: logstash -f /etc/logstash/conf.d/logstash.conf
  volumes:
    - ./logstash/config:/etc/logstash/conf.d
  ports:
    - "5000:5000"
    - "18080:18080"
  links:
    - elasticsearch
  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

How can I tune Elasticsearch configuration?

The Elasticsearch container is using the shipped configuration and it is not exposed by default.

If you want to override the default configuration, create a file elasticsearch/config/elasticsearch.yml and add your configuration in it.

Then, you'll need to map your configuration file inside the container in the docker-compose.yml. Update the elasticsearch container declaration to:

elasticsearch:
  build: elasticsearch/
  command: elasticsearch -Des.network.host=_non_loopback_
  ports:
    - "9200:9200"
  volumes:
    - ./elasticsearch/config/elasticsearch.yml:/usr/share/elasticsearch/config/elasticsearch.yml

You can also specify the options you want to override directly in the command field:

elasticsearch:
  build: elasticsearch/
  command: elasticsearch -Des.network.host=_non_loopback_ -Des.cluster.name: my-cluster
  ports:
    - "9200:9200"

Storage

By default, Elasticsearch data will be persisted into the ./esdata folder in this repository. Adjust as required to change it elsewhere if you need to.