Setting Up a Basic Logstash Pipeline

Let’s start with a simple example of a Logstash pipeline that reads data from a file, processes it, and sends it to Elasticsearch.

Step 1: Install Logstash

First, ensure you have Logstash installed. You can download and install it from the official Elastic website.

Step 2: Create a Configuration File

Create a configuration file named logstash.conf. This file will define the pipeline stages.

Step 3: Define the Input

In the input section, we specify where Logstash should read the data from. Here, we’ll use a file input:

input {
  file {
    path => "/path/to/your/logfile.log"
    start_position => "beginning"
  }
}

This configuration tells Logstash to read from logfile.log and start from the beginning of the file.

Step 4: Define the Filters

Filters are used to process and transform the data. Let’s use the grok filter to parse log entries and the date filter to process timestamps:

filter {
  grok {
    match => { "message" => "%{COMBINEDAPACHELOG}" }
  }
  date {
    match => [ "timestamp" , "dd/MMM/yyyy:HH:mm:ss Z" ]
  }
}

The grok filter parses Apache log entries using the COMBINEDAPACHELOG pattern. The date filter converts the timestamp into a format Elasticsearch can use.

Step 5: Define the Output

The output section specifies where the processed data should go. We’ll send it to Elasticsearch and also print it to the console for debugging:

output {
  elasticsearch {
    hosts => ["http://localhost:9200"]
    index => "apache-logs"
  }
  stdout {
    codec => rubydebug
  }
}

This configuration sends the data to Elasticsearch, indexing it under apache-logs, and prints each event to the console.

Step 6: Run Logstash

Save your configuration file and run Logstash with the following command:

bin/logstash -f logstash.conf

Logstash will start processing the log file, applying the filters, and sending the data to Elasticsearch.

Logstash, a key component of the Elastic Stack, is designed to collect, transform, and send data from multiple sources to various destinations. Configuring a Logstash pipeline is essential for effective data processing, ensuring that data flows smoothly from inputs to outputs while undergoing necessary transformations along the way.

This article will guide you through the process of configuring a Logstash pipeline, providing detailed examples and outputs to help you get started.