Version up

.gitlab-ci.yml

-image: docker:19.03.12
+image: docker:20.10.9
 
 variables:
   DOCKER_TLS_CERTDIR: "/certs"
-  IMAGE_VER: 4.0.2-1
+  IMAGE_VER: 4.2.3-1
 
 services:
-  - docker:19.03.12-dind
+  - docker:20.10.9-dind
 
 before_script:
   - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY

Dockerfile

-FROM graylog/graylog:4.0.2
+FROM graylog/graylog:4.2.3
 MAINTAINER Andrej Ramašeuski <andrej.ramaseuski@pirati.cz>
 RUN curl -L -o /usr/share/graylog/plugin/graylog-output-syslog-3.3.0.jar https://github.com/wizecore/graylog2-output-syslog/releases/download/3.3.0/graylog-output-syslog-3.3.0.jar