Example of logging with docker gelf logger to logstash

docker-compose.yml

---
version: '3'
services:
  elasticsearch:
    image: elasticsearch:5
  kibana:
    image: kibana:5
    ports:
    - "5601:5601"
  logstash:
    image: logstash:5
    command: -e 'input { gelf {} } filter { json { source => "message" } date { match => ["timestamp", "UNIX"] } mutate { remove_field => [ "command", "created" ] } }  output { elasticsearch { hosts => ["elasticsearch"] } stdout { } }'
    ports:
    - "12201:12201/udp"
  service1:
    image: php:7
    command: [ "php", "-r", 'for(;;){echo json_encode(["message" => "asd", "timestamp" => time(), "level" => "info"])."\n"; sleep(1);}']
    logging:
      driver: gelf
      options:
        gelf-address: udp://localhost:12201
        tag: service1