
Outputting the log data into Elasticsearch
The next step is going to be to execute the configuration so that Logstash can start reading logs from the Apache log file. In order to execute the Logstash configuration file, we need to run the following command:
bin/logstash -f /etc/logstash/conf.d/logs-apache.conf
The following screen is showing us the result after executing the preceding command. Once the command is executed successfully, we will get a message, such as Successfully started Logstash API endpoint {:port=>9600}:

When we execute the Logstash configuration, it connects to the output source, which in this case is Elasticsearch. This starts the pipeline so that it reads the data from the log file and puts it into Elasticsearch.
To test this setup, we need to open the browser so that we can open some localhost websites that are served through the Apache server, as this will provide some data for writing to the Apache log file. To test whether the logs have been pushed to Elasticsearch, we can open the Elasticsearch index and check the logs:
http://localhost:9200/logs_apache/_search?pretty

In the preceding screenshot, we can see that Logstash is reading the Apache logs and pushing them to the Elasticsearch server.