cassandra-docker

Cassandra in Docker

Running

This Docker image places all of the important Cassandra data, including data, commitlog, and configuration in the /data directory inside the container. For any data you might care about, /data must be mapped as a volume when you docker run. For situations where the data is disposable (e.g. tests), the volume may be omitted.

docker pull tobert/cassandra:2.1.1
mkdir /srv/cassandra
docker run -d -v /srv/cassandra:/data tobert/cassandra:2.1.1

Running a Cluster

When starting nodes for the first time, the cluster name will need to be set. This can be accomplished by pre-pushing a cassandra.yaml to $VOLUME/conf/cassandra.yaml or by passing the -name "NAME" option to the container on startup.

docker run -d tobert/cassandra:2.1.1 cassandra -name "Test Cluster"

Adding nodes to the cluster simply requires setting the seeds. Again, this can be done via cassandra.yaml or using a CLI argument to the container.

docker run -d tobert/cassandra:2.1.1 cassandra \
  -name "Test Cluster" \
  -seeds $IP_OF_SEED_NODE_OR_NODES

Accessing Tools

The usual Cassandra tooling is available via both the entrypoint and docker exec.

docker run -it --rm tobert/cassandra:2.1.1 cqlsh $HOST
docker run -it --rm tobert/cassandra:2.1.1 nodetool -h $HOST status
docker run -it --rm tobert/cassandra:2.1.1 cassandra-stress ...

docker exec -it $ID cqlsh
docker exec -it $ID nodetool status
docker exec -it $ID cassandra-stress ...

Memory Settings

You may set memory limits on the container using the -m switch, but this will cause problems if -m is smaller than the heap size configured in $VOL/conf/sproks/cassandra.yaml. All of the JVM arguments for Cassandra are stored there for this Docker image.

Building

It's a simple process. Build the entrypoint then build the image.

# get sprok and goyaml
go get -u github.com/tobert/sprok
go get -u gopkg.in/yaml.v2
# build the entrypoint binary
go build
# build the Docker image
sudo docker build .