Logstash integration guide

How to stream activity logs to logstash.

Logstash serves as a versatile data processing pipeline that ingests, transforms, and forwards logs from various sources to your preferred observability or SIEM tools. With its modular plugin architecture, Logstash enables flexible configuration of inputs, filters, and outputs—making it ideal for adapting log flows to fit evolving infrastructure needs.

This guide demonstrates how to configure a Logstash service running in Docker using Docker Compose to accept HTTP events from Defguard and forward them for further processing or storage.

Setup Logstash

Save the following config to logstash.conf . This will set up http input for Logstash on port 8002 and output the incoming data into stdout.

input {
  http {
    port => 8002
    codec => json_lines {
      target => "activity_data"
    }
  }
}
output {
  stdout { codec => rubydebug }
}

Add Logstash service to the docker-compose.yaml and start it.

  logstash:
    image: docker.elastic.co/logstash/logstash:8.14.0
    ports:
      - "8002:8002"
    volumes:
      - ./logstash.conf:/usr/share/logstash/pipeline/logstash.conf:ro

Add Logstash destination

In Defguard UI with an administrator account, go into settings page and choose Activity log streaming.

Click Add new and choose Logstash destination.

Fill out Name and Url fields and click Submit.

That's it! Defguard should now be sending activity events to Logstash, and you should see them printed to stdout in the running Logstash container.

To verify that everything is working, try logging in or out of defguard and check if the events appear in the Logstash stdout.

Basic Authentication

Basic Authentication is a simple HTTP authentication method that includes a username and password in the Authorization header of each request. To enable Basic Authentication for incoming log data, update your Logstash configuration as follows:

input {
  http {
    port => 8002
    codec => json_lines {
      target => "activity_data"
    }
    user => "logstash"
    password => "strongPassword"
  }
}
output {
  stdout { codec => rubydebug }
}

Modify Logstash destination in settings and fillusername and password in settings.

Logstash integration configuration

Name	Example value	Required	Logstash related configuration	Description
Name	Logstash			Assigned name for the destination.
Url	http(s)://127.0.0.1:8002		host, port	Address of running logstash HTTP source.
Username	logstash		user	username for Basic Authentication
Password	strongPassword		password	password for Basic Authentication
Cert	contents of cert.pem		ssl_certificate	Used for TLS connection