Enable Logstash's Beats input by default

The configuration from the official Docker image includes it by default:
https://github.com/elastic/logstash/blob/7.9/docker/data/logstash/pipeline/default.conf

More information about the Beats input plugin:
https://www.elastic.co/guide/en/logstash/current/plugins-inputs-beats.html

README.md

@@ -70,6 +70,7 @@ Other available stack variants:
 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

docker-compose.yml

@@ -41,6 +41,7 @@ services:
         target: /usr/share/logstash/pipeline
         read_only: true
     ports:
+      - "5044:5044"
       - "5000:5000/tcp"
       - "5000:5000/udp"
       - "9600:9600"

docker-stack.yml

@@ -27,6 +27,7 @@ services:
   logstash:
     image: docker.elastic.co/logstash/logstash:7.9.2
     ports:
+      - "5044:5044"
       - "5000:5000"
       - "9600:9600"
     configs:

logstash/pipeline/logstash.conf

@@ -1,4 +1,8 @@
 input {
+	beats {
+		port => 5044
+	}
+
 	tcp {
 		port => 5000
 	}