the Zipkin server is added to the Docker Compose files using an already existing Docker image, openzipkin/zipkin, published by the Zipkin project. In docker-compose.yml and docker-compose-partitions.yml, where RabbitMQ is used
The version of the Docker image, openzipkin/zipkin, is specified to be version 2.23.2.
The RABBIT_ADDRESSES=rabbitmq environment variable is used to specify that Zipkin will receive trace information using RabbitMQ and that Zipkin will connect to RabbitMQ using the hostname rabbitmq.
The STORAGE_TYPE=mem environment variable is used to specify that Zipkin will keep all trace information in memory.
The memory limit for Zipkin is increased to 1,024 MB, compared to 512 MB for all other containers. The reason for this is that since Zipkin is configured to keep all trace information in memory, it will consume more memory than the other containers after a while.
Zipkin exposes the HTTP port 9411 for web browsers to access its web user interface.
Docker will wait to start up the Zipkin server until the RabbitMQ service reports being healthy to Docker.
https://github.com/openzipkin-attic/docker-zipkin/blob/master/docker-compose.yml