Kubernetes provides excellent support for stateful applications, such as MySQL, through the use of persistent volumes. These persistent volumes are used to create permanent Kubernetes storage for pods and containers. This allows you to deploy and manage all of the constituent services that make up your enterprise architecture using a single, scalable platform.
With NetApp Astra Trident, the Container Storage Interface (CSI)-compliant dynamic storage provisioner, underlying storage for persistent volumes can be allocated across NetApp storage solutions. With Cloud Volumes ONTAP and Trident, you can add enterprise-grade persistent data management capabilities to containerized applications in your Kubernetes cluster.
In this article, we discuss the benefits of deploying database storage with Cloud Volumes ONTAP, and demonstrate how to set it up with your MySQL Kubernetes deployments using Trident.
Click to jump directly to the How to Set Up a Kubernetes MySQL Deployment with Cloud Volumes ONTAP section.
Before we go into the details of how to set up MySQL Kubernetes deployments with Cloud Volumes ONTAP, let’s take a look at why you’d choose to do that in the first place.
As one of the most popular database solutions, there are both managed and self-managed options to deploy MySQL. In a managed service approach like AWS RDS, Azure MySQL, or GCP Cloud SQL, users don’t need to take care of underlying database infrastructure. But in self-managed or DIY SQL deployments, which appeal to enterprise-scale companies, there’s room for design.
Self-managed MySQL deployments can either be VM-based or built on containers, if you follow a fully containerized microservices-based architecture for your applications. In such deployment you have to use the right storage layer to ensure that your database performance is not impacted. That’s where Cloud Volumes ONTAP can become essential.
Cloud Volumes ONTAP is NetApp’s cloud-based data management platform for AWS, Google Cloud and Azure. NetApp Astra Trident is a CSI-compliant provisioner for Kubernetes that performs dynamic storage provisioning using Cloud Volumes ONTAP for cloud as well as on-premises ONTAP storage systems. Together they offer a comprehensive set of features for working with persistent data storage:
The following provides an example of deploying a single Kubernetes MySQL instance using Trident.
apiVersion: storage.k8s.io/v1beta1
kind: StorageClass
metadata:
name: mysql-sc
provisioner: csi.trident.netapp.io
reclaimPolicy: Retain
mountOptions:
- debug
parameters:
backendType:ontap-nas
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: mysql-pvc
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 100Gi
storageClassName: mysql-sc
The volume gets provisioned by Trident when the claim is created. This claim is then used by a pod to mount and use the provisioned volume. A reclaim policy of retain has also been specified in the StorageClass definition, which will prevent the persistent volume from being deleted if the pod releases the claim.
As shown below, we simply need to reference our previously defined PersistentVolumeClaim and specify where the bound persistent volume should be mounted within our MySQL Kubernetes container.
apiVersion: apps/v1
kind: Deployment
metadata:
name: mysql-server
labels:
app: mysqldb
spec:
selector:
matchLabels:
app: mysqldb
tier: db
strategy:
type: Recreate
template:
metadata:
labels:
app: mysqldb
tier: db
spec:
containers:
- image: mysql:5.6
name: mysql
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name:mysql-pass
key:password<
ports:
- containerPort: 3306
name: mysql
volumeMounts:
- name: mysql-pv
mountPath: /var/lib/mysql
volumes:
- name: mysql-pv
persistentVolumeClaim:
claimName: mysql-pvc
And that is it—your Kubernetes MySQL deployment is now set up.
We can additionally set up test instances of our Kubernetes MySQL database by creating snapshots of existing volumes using the K8s Volume Snapshot feature. With Trident, the FlexClone technology is used in the backend to create persistent volumes from these snapshots. The first step in the process is creation of a VolumeSnapshotClass. That command is then used to create a VolumeSnapshot from an existing PVC. Get step-by-step instructions on setting up Kubernetes volume cloning process here. In this case, the cloning operation is handled transparently by Astra Trident from the underlying storage volume.
Kubernetes provides a complete solution for running both stateless and stateful applications, with the extensible flexibility to integrate with various cloud storage solutions through its persistent volumes and provisioner paradigms. Trident makes it possible to integrate Kubernetes with Cloud Volumes ONTAP, giving access to a whole host of data protection and data management benefits that are vital for running database platforms, including MySQL Kubernetes deployments.