The CassKop Cassandra Kubernetes operator makes it easy to run Apache Cassandra on Kubernetes. Apache Cassandra is a popular, free, open-source, distributed wide column store, NoSQL database management system. The operator allows to easily create and manage racks and data centers aware Cassandra clusters.
The Cassandra operator is based on the CoreOS operator-sdk tools and APIs.
NOTE: This is an alpha-status project. We do regular tests on the code and functionality, but we can not assure a production-ready stability at this time. Our goal is to make it run in production as quickly as possible.
CassKop creates/configures/manages Cassandra clusters atop Kubernetes and is by default space-scoped which means that :
- CassKop is able to manage X Cassandra clusters in one Kubernetes namespace.
- You need X instances of CassKop to manage Y Cassandra clusters in X different namespaces (1 instance of CassKop per namespace).
This adds security between namespaces with a better isolation, and less work for each operator.
We have some slides for a CassKop demo
You can also play with CassKop on Katacoda
CassKop deals with Cassandra clusters on one datacenter. For multi-dacenters deployments, please use MultiCassKop in addition to CassKop. This second operator is part of this same repository.
The following features are supported by CassKop:
- Deployment of a C* cluster (rack or AZ aware)
- Scaling up the cluster (with cleanup)
- Scaling down the cluster (with decommission prior to Kubernetes scale down)
- Pods operations (removenode, upgradesstable, cleanup, rebuild..)
- Adding a Cassandra DC
- Removing a Cassandra DC
- Setting and modifying configuration files
- Setting and modifying configuration parameters
- Update of the Cassandra docker image
- Rolling update of a Cassandra cluster
- Update of Cassandra version (including upgradesstable in case of major upgrade)
- Update of JVM
- Update of configuration
- Rolling restart of a Cassandra rack
- Stopping a Kubernetes node for maintenance
- Process a remove node (and create new Cassandra node on another Kubernetes node)
- Process a replace address (of the old Cassandra node on another Kubernetes node)
- Manage operations on pods through CassKop plugin (cleanup, rebuild, upgradesstable, removenode..)
- Monitoring (using Instaclustr Prometheus exporter to Prometheus/Grafana)
- Use official Cassandra Image (configuration for Casskop is done through a bootstrap init-container)
- Performing live backup of Cassandra datas (using Instaclustr sidecar)
- Performing live restore of datas (using Instaclustr sidecar)
- Performing live Cassandra repairs through the use of Cassandra reaper
- Pause/Restart & rolling restart operations through CassKoP plugin.
CassKop doesn't use nodetool but invokes operations through authenticated JMX/Jolokia call
Operator SDK is part of the operator framework provided by RedHat & CoreOS. The goal is to provide high-level abstractions that simplifies creating Kubernetes operators.
The quick start guide walks through the process of building the Cassandra operator using the SDK CLI, setting up the RBAC, deploying the operator and creating a Cassandra cluster.
You can find this in the Developer section
Users should only need Kubectl & helm cli
- kubectl version v1.13.3+.
- Helm version v2.12.2+.
- Access to a Kubernetes v1.13.3+ cluster.
- Cassandra needs fast local storage (we have tested with local storage provisioner, GKE ssd storage, and Rancher local-path-provisioner)
You can install the plugin by copying the file into your PATH.
We uses CircleCI as our CI tool to build and test the operator.
To accelerate build phases we have created a custom build-image used by the CircleCI pipeline:
https://cloud.docker.com/u/orangeopensource/repository/docker/orangeopensource/casskop-build
You can find more info in the developer Section
The Cassandra operator image is automatically built and stored on Docker Hub
The operator works with specific Docker Cassandra image which is build in the repository: https://github.com/Orange-OpenSource/cassandra-image
This table shows compatibility between CassKop and associated Cassandra image
| Operator | Cassandra-k8s |
|---|---|
| 0.3.1-release | >= 3.11.4-8u212-0.3.1 |
| 0.3.2-release | >= 3.11.4-8u212-0.3.2-release |
| 0.3.3-release | >= 3.11.4-8u212-0.3.3-release |
| 0.4.0-release | >= 3.11.4-8u212-0.4.0-release |
docker image: orangeopensource/cassandra-image:3.11.4-8u212-0.4.0-release or 3.11.4-8u212-0.4.0-release-cqlsh if you need cqlsh
First, we need to create a Kubernetes namespace in order to host our operator & cluster
kubectl create namespace cassandra
To ease the use of the Cassandra operator, a Helm chart has been created
We are looking where to store our helm in the future
If it is the 1rst time you deploy a chart with Helm, you may need to install the helm client and tiller, and create the service account for tiller (more informations about how to create a tiller service account here.
helm init --history-max 200 kubectl create serviceaccount tiller --namespace kube-system kubectl create -f tiller-clusterrolebinding.yaml helm init --service-account tiller --upgrade
You will need to manually install the crds beforehand
kubectl apply -f https://raw.githubusercontent.com/Orange-OpenSource/casskop/master/deploy/crds/db_v1alpha1_cassandracluster_crd.yaml
Add the Helm incubator repo if you do not already have it:
helm repo add orange-incubator https://orange-charts-incubator.storage.googleapis.com
Get the latest information about charts from the chart repositories.
helm repo update
helm install --name casskop orange-incubator/cassandra-operator
Remove --name from the command
Deploy CassKop:
$ helm install --name casskop orange-incubator/cassandra-operator
NAME: casskop
LAST DEPLOYED: Thu May 23 15:34:27 2019
NAMESPACE: cassandra-demo
STATUS: DEPLOYED
RESOURCES:
==> v1/ServiceAccount
NAME SECRETS AGE
casskop 1 0s
==> v1beta1/Role
NAME AGE
casskop 0s
==> v1/RoleBinding
NAME AGE
casskop 0s
==> v1/Deployment
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
casskop-casskop 1 1 1 0 0s
==> v1/Pod(related)
NAME READY STATUS RESTARTS AGE
casskop-casskop-78786b9bf-cjggg 0/1 ContainerCreating 0
0sYou can find more information in the Cassandra operator Helm readme
If you have problem you can see troubleshooting section
This creates a Kubernetes Deployment for the operator, with RBAC settings.
Once deployed, you may find the Pods created by the Charts. If you deploy a release
named casskop, then your pod will have a name similar to :
$ kubectl get pod
NAME READY STATUS RESTARTS AGE
casskop-cassandra-operator-78786b9bf-cjggg 1/1 Running 0 1h
You can view the CassKop logs using
$ kubectl logs -f cassandra-cassandra-operator-78786b9bf-cjggg
The charts also deploy the cassandracluster CRD we can check that it is deployed:
$ kubectl get crd
NAME AGE
...
cassandraclusters.db.orange.com 1h
...
Once the operator is deployed inside a Kubernetes cluster, a new API will be accessible, so you'll be able to create, update and delete cassandraclusters.
In order to deploy a new cassandra cluster a specification has to be created. As an example :
kubectl apply -f samples/cassandracluster.yaml
See pods coming to life :
kubectl get pods -w
You can watch the status updates in real time on your CassandraCluster object :
watch 'kubectl describe cassandracluster cassandra-demo | tail -20'
You can find mode information on the CassandraCluster.status in this section
You can do a lot of operations on your Cassandra cluster.
If the Cassandra operator restarts, it can recover its previous state thanks to the CRD objects
CassandraClusters which stored directly in Kubernetes, description and state of the Cassandra cluster.
Upgrading the operator consists in uninstalling the current version and installing the new version :
helm uninstall casskop
helm repo update
helm install --name casskop casskop/cassandra-operator
It's also possible to decide to temporarily install a developement release by specifying the image tag to use :
helm install --name casskop casskop/cassandra-operator --set debug.enabled=true --no-hooks \
--set image.tag=v0.5.0b-branch1
If you want to delete the operator from your Kubernetes cluster, the operator deployment should be deleted.
$ helm delete casskop
The command removes all the Kubernetes components associated with the chart and deletes the helm release.
The CRD created by the chart are not removed by default and should be manually cleaned up (if required)
Manually delete the CRD:
kubectl delete crd cassandraclusters.dfy.orange.com
!!!!!!!!WARNING!!!!!!!!
If you delete the CRD then !!!!!!WAAAARRRRNNIIIIINNG!!!!!!
It will delete ALL Clusters that has been created using this CRD!!!
Please never delete a CRD without very very good care
CassKop is build using operator SDK:
We can quickly setup monitoring for our deployed Cassandra nodes using Prometheus operator.
You can deploy the CoreOs Prometheus operator on your cluster: You can find example helm value.yaml to configure the Prometheus operator:
$ kubectl create namespace monitoring
$ helm install --namespace monitoring --name prometheus stable/prometheus-operatorThen you have to define a ServiceMonitor object to monitor cluster deployed by your cassandra operator (one time), update this to specify which namespace to monitor.
cassandra-service-monitor.yml
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
name: kube-prometheus-cassandra-k8s-jmx
labels:
k8s-apps: cassandra-k8s-jmx
prometheus: kube-prometheus
component: cassandra
release: prometheus
spec:
jobLabel: kube-prometheus-cassandra-k8s-jmx
selector:
matchLabels:
k8s-app: exporter-cassandra-jmx
namespaceSelector:
matchNames:
- cassandra
- cassandra-demo
- default
endpoints:
- port: promjmx
interval: 15sYour namespace need to be listed in the namespaceSelector section.
You can import this dashboard to retrieve metrics about your Cassandra cluster.
See CONTRIBUTING for details on submitting patches and the contribution workflow.
You can contact the team with our mailing-list prj.casskop.support@list.orangeportails.net and join our slack https://casskop.slack.com (request sent to that ML)
CassKop is under Apache 2.0 license. See the LICENSE file for details.