New to KubeDB? Please start here.
Restart FerretDB
KubeDB supports restarting the FerretDB via a FerretDBOpsRequest. Restarting is useful if some pods are got stuck in some phase, or they are not working correctly. This tutorial will show you how to use that.
Before You Begin
At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.
Now, install KubeDB cli on your workstation and KubeDB operator in your cluster following the steps here.
To keep things isolated, this tutorial uses a separate namespace called
demothroughout this tutorial.
$ kubectl create ns demo
namespace/demo created
Note: YAML files used in this tutorial are stored in docs/examples/ferretdb folder in GitHub repository kubedb/docs.
Deploy FerretDB
In this section, we are going to deploy a FerretDB using KubeDB.
apiVersion: kubedb.com/v1alpha2
kind: FerretDB
metadata:
name: ferretdb
namespace: demo
spec:
version: "2.0.0"
backend:
storage:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 500Mi
deletionPolicy: WipeOut
Let’s create the FerretDB CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2025.7.31/docs/examples/ferretdb/restart/ferretdb.yaml
ferretdb.kubedb.com/ferretdb created
Apply Restart opsRequest
apiVersion: ops.kubedb.com/v1alpha1
kind: FerretDBOpsRequest
metadata:
name: restart-ferretdb
namespace: demo
spec:
type: Restart
databaseRef:
name: ferretdb
timeout: 3m
apply: Always
spec.typespecifies the Type of the ops Requestspec.databaseRefholds the name of the FerretDB. The ferretdb should be available in the same namespace as the opsRequest- The meaning of
spec.timeout&spec.applyfields will be found here
Let’s create the FerretDBOpsRequest CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2025.7.31/docs/examples/ferretdb/restart/ops.yaml
ferretdbopsrequest.ops.kubedb.com/restart-ferretdb created
Now the Ops-manager operator will restart the pods one by one.
$ kubectl get frops -n demo
NAME TYPE STATUS AGE
restart-ferretdb Restart Successful 2m15s
$ kubectl get frops -n demo -oyaml restart-ferretdb
apiVersion: ops.kubedb.com/v1alpha1
kind: FerretDBOpsRequest
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"ops.kubedb.com/v1alpha1","kind":"FerretDBOpsRequest","metadata":{"annotations":{},"name":"restart-ferretdb","namespace":"demo"},"spec":{"apply":"Always","databaseRef":{"name":"ferretdb"},"timeout":"3m","type":"Restart"}}
creationTimestamp: "2024-10-21T12:38:38Z"
generation: 1
name: restart-ferretdb
namespace: demo
resourceVersion: "367859"
uid: 0ca77cab-d354-43a4-ba85-c31f1f6e685d
spec:
apply: Always
databaseRef:
name: ferretdb
timeout: 3m
type: Restart
status:
conditions:
- lastTransitionTime: "2024-10-21T12:38:38Z"
message: FerretDBOpsRequest has started to restart FerretDB nodes
observedGeneration: 1
reason: Restart
status: "True"
type: Restart
- lastTransitionTime: "2024-10-21T12:38:46Z"
message: get pod; ConditionStatus:True; PodName:ferretdb-0
observedGeneration: 1
status: "True"
type: GetPod--ferretdb-0
- lastTransitionTime: "2024-10-21T12:38:46Z"
message: evict pod; ConditionStatus:True; PodName:ferretdb-0
observedGeneration: 1
status: "True"
type: EvictPod--ferretdb-0
- lastTransitionTime: "2024-10-21T12:38:51Z"
message: check pod running; ConditionStatus:True; PodName:ferretdb-0
observedGeneration: 1
status: "True"
type: CheckPodRunning--ferretdb-0
- lastTransitionTime: "2024-10-21T12:38:56Z"
message: Successfully restarted FerretDB nodes
observedGeneration: 1
reason: RestartNodes
status: "True"
type: RestartNodes
- lastTransitionTime: "2024-10-21T12:38:56Z"
message: Controller has successfully restart the FerretDB replicas
observedGeneration: 1
reason: Successful
status: "True"
type: Successful
observedGeneration: 1
phase: Successful
Cleaning up
To clean up the Kubernetes resources created by this tutorial, run:
kubectl delete ferretdbopsrequest -n demo restart-ferretdb
kubectl delete ferretdb -n demo ferretdb
kubectl delete ns demo
Next Steps
- Detail concepts of FerretDB object.
- Monitor your FerretDB database with KubeDB using out-of-the-box Prometheus operator.
- Monitor your FerretDB database with KubeDB using out-of-the-box builtin-Prometheus.
- Detail concepts of FerretDB object.
- Want to hack on KubeDB? Check our contribution guidelines.