Cassandra Operator

Project Status: pre-alpha

Cassandra Operator - This is a Kubernetes Operator for Cassandra

The goal of this Operator is to support various life-cycle actions for a Cassandra instance, such as:

• Decommission a C* instance
• Bootstrap a C* instance
• Configuring authentication

This Cassandra operator is implemented using the operator-sdk. The SDK CLI operator-sdk generates the project layout and controls the development life cycle. In addition, this implementation replaces the use of client-go with the SDK APIs to watch, query, and mutate Kubernetes resources.

Quick Start

The quick start guide walks through the process of building the Cassandra operator image using the SDK CLI, setting up the RBAC, deploying operators, and creating a Cassandra cluster.

Prerequisites

• dep version v0.4.1+.
• go version v1.10+.
• docker version 17.03+.
• kubectl version v1.9.0+.
• Access to a kubernetes v.1.9.0+ cluster. The cassandra-operator uses apps/v1 statefulset, the Kubernetes cluster version should be greater than 1.9.

Note: This guide uses quay.io for the public registry.

Prerequisites Dynamic volume provisioning and storage class configured in Kubernetes. The StatefulSet controller managed by the operator creates PersistentVolumeClaims that are bound to PersistentVolumes, that the cluster should dynamically provision. A manifest for local storage class is included as example in deploy/storage/, local volumes is an alpha feature that requires the PersistentLocalVolumes feature gate to be enabled if Kubernetes cluster version is lower than v.1.10.

Install the Operator SDK CLI

First, checkout and install the operator-sdk CLI:

$ cd $GOPATH/src/github.com/operator-framework/operator-sdk
$ git checkout tags/v0.0.5
$ dep ensure
$ go install github.com/operator-framework/operator-sdk/commands/operator-sdk

Initial Setup

Checkout this Vault Operator repository:

$ mkdir $GOPATH/src/github.com/camilocot
$ cd $GOPATH/src/github.com/camilocot
$ git clone https://github.com/camilocot/cassandra-operator.git
$ cd cassandra-operator

Vendor the dependencies:

$ dep ensure

Build and run the operator

Build the Cassandra operator image and push it to a public registry such as quay.io:

$ export IMAGE=quay.io/example/casandra-operator:v0.0.1
$ operator-sdk build $IMAGE
$ docker push $IMAGE

Setup RBAC for the Vault operator and its related resources:

$ kubectl create -f deploy/rbac.yaml

Deploy the Cassandra operator:

$ kubectl create -f deploy/operator.yaml

Deploying a Cassandra cluster

Create a Cassandra cluster:

$ kubectl create -f deploy/cr.yaml

Verify that the Cassandra cluster is up:

$ kubectl get pods -l app=cassandra

Other operators used as reference

• Zalando Postgres
• Vault
• Etcd
• Prometheus
• Redis
• ArangoDB
• TensorFlow
• Prometheus Jmx Exporter
• Flux Operator
• ElasticSearch Operator
• Wildfly Operator