Wouldn’t be a nice feature to use Rados Block Devices for Kubernetes persistent storage?
Most of the steps used to setup a basic Kubernetes cluster are presented here and will detail only the Ceph integration part.
Presuming that Kubernetes cluster is up and running jumping to the next steps:
Creating the rbd volume
On cephadmin node:
rbd create kube_ceph -s 10240 --image-feature layering
rbd map kube_ceph
mkfs.xfs /dev/rbd0
rbd unmap kube_ceph
Preparing Kubernetes to embrace Ceph
On any ceph node:
ceph auth get-key client.admin
echo "AQDT5ppYCuM3ChAAXOkw8h4ii7qsnybdXV9D1g==" | base64 > secret.txt
On Kubernetes master node:
vi ceph-secret.yml
apiVersion: v1
kind: Secret
metadata:
name: ceph-secret
data:
key: < cat secret.txt here >
vi ceph-pv.yml
apiVersion: v1
kind: PersistentVolume
metadata:
name: ceph-pv
spec:
capacity:
storage: 10Gi
accessModes:
– ReadWriteMany
rbd:
monitors:
– knode01:6789
– knode02:6789
– knode03:6789
pool: rbd
image: kube_ceph
user: admin
secretRef:
name: ceph-secret
fsType: xfs
readOnly: false
vi ceph-pv-claim.yml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: ceph-claim
spec:
accessModes:
– ReadWriteMany
resources:
requests:
storage: 10Gi
kubectl create -f ceph-secret.yml
kubectl get secret
You should receive a similar output:
[root@master ~]# kubectl get secret
NAME TYPE DATA AGE
ceph-secret Opaque 1 1d
default-token-cgstk kubernetes.io/service-account-token 3 2d
kubectl create -f ceph-pv.yml
kubectl create -f ceph-pv-claim.yml
Now let’s create a MySQL pod with Ceph Persistent Storage
vi myqsl-pod.yml
apiVersion: v1
kind: Pod
metadata:
name: ceph-mysql
spec:
containers:
– name: ceph-mysql
image: tutum/mysql
ports:
– name: mysql-db
containerPort: 3306
volumeMounts:
– name: mysql-pv
mountPath: /var/lib/mysql
volumes:
– name: mysql-pv
persistentVolumeClaim:
claimName: ceph-claim
kubectl create -f mysql-pod.yml
And now you can enjoy your new MySQL container that has Ceph backed storage.
