Docker Compose allows building multi-container applications and running them on the local machine, resources permitting) It's easy to configure and operate, making it a very useful tool for development.
- Docker
- Docker Compose
- Cluster monitor image built and published to local Docker repository
In order to start application on your machine, navigate your shell to this
directory in git repository clone on your disk. Then it's advisable to set
COMPOSE_PROJECT_NAME environment variable to something sensible because
by default, Docker Compose will derive it from directory name. Let's assume
export COMPOSE_PROJECT_NAME=example
Then run:
docker-compose up -d
This will launch etcd server and a single Akka cluster node. You can spawn 3 more nodes like this:
docker-compose scale monitor=4
You can can observe the new nodes joining the cluster by viewing logs thorough Docker / Docker Compose log facility:
docker-commpose logs
Then, open a second terminal window and stop the original cluster leader:
docker stop example_monitor_1
In the terminal window streaming application logs, you should observe the node being removed from the cluster and another node taking over leader role. You can then restart the node and obsere it re-joning the cluster:
docker start example_monitor_1
When you are done, run the following commands to stop and discard the containers:
docker-compose stop
docker-compose rm