downgrade to elastic.co docker images 7.x

the reason is because in 8.x, it is more complicated to connect filebeat-logstash-elasticsearch secure communication with ES.

README.md

@@ -119,9 +119,10 @@ The goal of this project is to implement a [`Spring Boot`](https://docs.spring.i
  - Click `Explore on my own`
  - On the main page, click the _"burger"_ menu icon, then click `Discover`
  - Click `Create index pattern` button
- - In the `Name` field, set `filebeat-*`
- - In the `Timestamp field` combo-box, select `@timestamp`
- - Click `Create index pattern` button
+ - In the `Create index pattern` form
+ - Set `filebeat-*` fot the `Name` field
+ - Select `@timestamp` for the `Timestamp field` combo-box
+ - Click `Create index pattern` button
  - Click the _"burger"_ menu icon again and then click `Discover` to start performing searches
 
  ![kibana](documentation/kibana.jpeg)

docker-compose.yml

@@ -15,7 +15,7 @@ services:
  test: "mysqladmin ping -u root -p$${MYSQL_ROOT_PASSWORD}"
 
  elasticsearch:
- image: docker.elastic.co/elasticsearch/elasticsearch:8.5.3
+ image: docker.elastic.co/elasticsearch/elasticsearch:7.17.9
  container_name: elasticsearch
  restart: unless-stopped
  ports:
@@ -29,7 +29,7 @@ services:
  test: "curl -f http:https://localhost:9200 || exit 1"
 
  logstash:
- image: docker.elastic.co/logstash/logstash:8.5.3
+ image: docker.elastic.co/logstash/logstash:7.17.9
  container_name: logstash
  restart: unless-stopped
  ports:
@@ -42,13 +42,13 @@ services:
  test: "curl -f http:https://localhost:9600 || exit 1"
 
  kibana:
- image: docker.elastic.co/kibana/kibana:8.5.3
+ image: docker.elastic.co/kibana/kibana:7.17.9
  container_name: kibana
  restart: unless-stopped
  ports:
  - "5601:5601"
  environment:
- ELASTICSEARCH_URL: http:https://elasticsearch:9200
+ ELASTICSEARCH_HOSTS: http:https://elasticsearch:9200
  depends_on:
  - elasticsearch
  healthcheck:

filebeat/Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.elastic.co/beats/filebeat:8.5.3
+FROM docker.elastic.co/beats/filebeat:7.17.9
 
 # Copy our custom configuration file
 COPY filebeat.yml /usr/share/filebeat/filebeat.yml