Graylog docker-compose for Synology DSM 7 deployment

docker-compose.yml

# My article on this: 
# I use PUID and PGID as environments variables, but I removed it from this snipped
# Change the passwords especially if this is externally exposed
# TIP: It takes a while for the graylog interface to come up, so check for errors and be patient
version: "3.7"

services:
  mongo:
    container_name: mongo
    image: mongo:4.4.18
    networks:
      - graylog

  elasticsearch:
    container_name: elasticsearch
    image: docker.elastic.co/elasticsearch/elasticsearch-oss:7.10.2
    environment:
      - http.host=0.0.0.0
      - transport.host=localhost
      - network.host=0.0.0.0
      - "ES_JAVA_OPTS=-Dlog4j2.formatMsgNoLookups=true -Xms512m -Xmx512m"
    ulimits:
      memlock:
        soft: -1
        hard: -1
    deploy:
      resources:
        limits:
          memory: 1g
    networks:
      - graylog

  graylog:
    container_name: graylog
    image: graylog/graylog:4.3.11
    environment:
      - GRAYLOG_PASSWORD_SECRET=CHANGEME_MIN16CHARS
      # Password: the password below is `admin` sha256 hashed, make your own with: echo -n your_pass | sha256sum
      - GRAYLOG_ROOT_PASSWORD_SHA2=8c6976e5b5410415bde908bd4dee15dfb167a9c873fc4bb8a81f6f2ab448a918
      - GRAYLOG_HTTP_EXTERNAL_URI=http://127.0.0.1:9000/
    #      - PUID=1111
    #      - PGID=100
    entrypoint: /usr/bin/tini -- wait-for-it elasticsearch:9200 --  /docker-entrypoint.sh
    networks:
      - graylog
    restart: always
    depends_on:
      - mongo
      - elasticsearch
    ports:
      # Graylog web interface and REST API
      - 9000:9000
      # Syslog TCP
      - 1514:1514
      # Syslog UDP
      - 1514:1514/udp
      # GELF TCP
      - 12201:12201
      # GELF UDP
      - 12201:12201/udp

networks:
  graylog:
    driver: bridge