sukolupo / cassandra-docker-swarm

This repo contains code and test files to setup cassandra using docker swarm

cassandra-docker-swarm

This repo contains code and test files to setup cassandra using docker swarm

Building your own Custom image

Use the playbook calls below to build the docker image (if required).

A prebuilt docker image can be found here https://hub.docker.com/r/sukolupo/cassandra

Don't forget to call "docker login" before running the playbook, otherwise it will fail on upload.

Example Call

Will create a custom image with the tag 0.1

ansible-playbook ./cassandra_build_image.yml -i localhost, --extra-vars='new_image_tag="0.1"'

Will create a custom image in a different repo and tag

ansible-playbook ./cassandra_build_image.yml -i localhost, --extra-vars='new_image_tag="0.2" image_repo="myrepo"'

Testing using Vagrant

The repo contains all the configuration files to test. The images are based on CentOS7

run the following to spin up the four node environment

vagrant up

As part of the setup it should also pull from this repo, so all the code is ready to go.

cd ~/git/cassandra-docker-swarm

The Nodes

• Master - Standalone node outside of the swarm. I use this to test external connectivity using cqlsh

• Node1 - The Leader node.

• Node2 - Worker node.

• Node3 - Worker node.

SSH is configured so you shoud be able to connect between each of the nodes without using passwords.

Setting up the Swarm

I have created a playbook to setup and configure the docker swarm, you can provide your own inventory files to setup a swarm on any machines you like.

I have provided a inventory file to work with the test vagrant environment.

Example Call

Will create a 3 node docker swarm.

ansible-playbook ./docker_create_swarm.yml -i ./hosts/vagrant_hosts

Deploying the Stack

To deploy the cassandra stack run the following;

docker stack deploy -c /vagrant/docker-compose-cassandra.yaml <cluster name>

This will create one cassandra node.

Once the node is up and running

docker exec -it <container> bash -c 'nodetool status'

You can scale the cluster by running the following;

docker service scale <cluster name>_cassandra=2

Test Connectivity from Outside of the Swarm

Determine the port mapped to 9042.

docker stack services <cluster name>

The output should show the mapping.

Now run the following to connect;

cqlsh node1 <exposed port> --cqlversion="3.4.4"