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Manage KubeDB objects using CLIs

KubeDB CLI

KubeDB comes with its own cli. It is called kubedb cli. kubedb can be used to manage any KubeDB object. kubedb cli also performs various validations to improve ux. To install KubeDB cli on your workstation, follow the steps here.

How to Create objects

kubedb create creates a database CRD object in default namespace by default. Following command will create a MySQL object as specified in mysql.yaml.

$ kubedb create -f mysql-demo.yaml
mysql.kubedb.com/mysql-demo created

You can provide namespace as a flag --namespace. Provided namespace should match with namespace specified in input file.

$ kubedb create -f mysql-demo.yaml --namespace=kube-system
mysql.kubedb.com/mysql-demo created

kubedb create command also considers stdin as input.

cat mysql-demo.yaml | kubedb create -f -

To learn about various options of create command, please visit here.

How to List Objects

kubedb get command allows users to list or find any KubeDB object. To list all MySQL objects in default namespace, run the following command:

$ kubedb get mysql
NAME         VERSION   STATUS    AGE
mysql-demo   8.0-v1    Running   2m
mysql-dev    8.0-v1    Running   1m
mysql-prod   8.0-v1    Running   1m
mysql-qa     8.0-v1    Running   1m

To get YAML of an object, use --output=yaml flag.

$ kubedb get mysql mysql-demo --output=yaml
apiVersion: kubedb.com/v1alpha1
kind: MySQL
metadata:
  creationTimestamp: 2018-09-27T13:07:23Z
  finalizers:
  - kubedb.com
  generation: 2
  name: mysql-demo
  namespace: default
  resourceVersion: "19279"
  selfLink: /apis/kubedb.com/v1alpha1/namespaces/default/mysqls/mysql-demo
  uid: 46034ac3-c256-11e8-b2cc-080027d9f35e
spec:
  databaseSecret:
    secretName: mysql-demo-auth
  podTemplate:
    controller: {}
    metadata: {}
    spec:
      resources: {}
  replicas: 1
  serviceTemplate:
    metadata: {}
    spec: {}
  storage:
    accessModes:
    - ReadWriteOnce
    resources:
      requests:
        storage: 50Mi
    storageClassName: standard
  storageType: Durable
  terminationPolicy: Pause
  updateStrategy:
    type: RollingUpdate
  version: 8.0-v1
status:
  observedGeneration: 2$4213139756412538772
  phase: Running

To get JSON of an object, use --output=json flag.

kubedb get mysql mysql-demo --output=json

To list all KubeDB objects, use following command:

$ kubedb get all -o wide
NAME                          VERSION   STATUS    AGE
mysql.kubedb.com/mysql-demo   8.0-v1    Running   3m
mysql.kubedb.com/mysql-dev    8.0-v1    Running   2m
mysql.kubedb.com/mysql-prod   8.0-v1    Running   2m
mysql.kubedb.com/mysql-qa     8.0-v1    Running   2m

NAME                                DATABASE              BUCKET              STATUS      AGE
snap/mysql-demo-20170605-073557     my/mysql-demo         gs:bucket-name      Succeeded   9m
snap/snapshot-20171212-114700       my/mysql-demo         gs:bucket-name      Succeeded   1h

Flag --output=wide is used to print additional information.

List command supports short names for each object types. You can use it like kubedb get <short-name>. Below are the short name for KubeDB objects:

  • MySQL: my
  • Snapshot: snap
  • DormantDatabase: drmn

You can print labels with objects. The following command will list all Snapshots with their corresponding labels.

$ kubedb get snap --show-labels
NAME                          DATABASE              STATUS      AGE       LABELS
mysql-demo-20170605-073557    my/mysql-demo         Succeeded   11m       kubedb.com/kind=MySQL,kubedb.com/name=mysql-demo
snapshot-20171212-114700      my/mysql-demo         Succeeded   1h        kubedb.com/kind=MySQL,kubedb.com/name=mysql-demo

You can also filter list using --selector flag.

$ kubedb get snap --selector='kubedb.com/kind=MySQL' --show-labels
NAME                          DATABASE         STATUS      AGE       LABELS
mysql-demo-20171212-073557    my/mysql-demo    Succeeded   14m       kubedb.com/kind=MySQL,kubedb.com/name=mysql-demo
snapshot-20171212-114700      my/mysql-demo    Succeeded   2h        kubedb.com/kind=MySQL,kubedb.com/name=mysql-demo

To print only object name, run the following command:

$ kubedb get all -o name
mysql/mysql-demo
mysql/mysql-dev
mysql/mysql-prod
mysql/mysql-qa
snapshot/mysql-demo-20170605-073557
snapshot/snapshot-20170505-114700

To learn about various options of get command, please visit here.

How to Describe Objects

kubedb describe command allows users to describe any KubeDB object. The following command will describe MySQL database mysql-demo with relevant information.

$ kubedb describe my mysql-demo
Name:               mysql-demo
Namespace:          default
CreationTimestamp:  Thu, 27 Sep 2018 19:07:23 +0600
Labels:             <none>
Annotations:        <none>
Replicas:           1  total
Status:             Running
  StorageType:      Durable
Volume:
  StorageClass:  standard
  Capacity:      50Mi
  Access Modes:  RWO

StatefulSet:
  Name:               mysql-demo
  CreationTimestamp:  Thu, 27 Sep 2018 19:07:25 +0600
  Labels:               kubedb.com/kind=MySQL
                        kubedb.com/name=mysql-demo
  Annotations:        <none>
  Replicas:           824638226772 desired | 1 total
  Pods Status:        1 Running / 0 Waiting / 0 Succeeded / 0 Failed

Service:
  Name:         mysql-demo
  Labels:         kubedb.com/kind=MySQL
                  kubedb.com/name=mysql-demo
  Annotations:  <none>
  Type:         ClusterIP
  IP:           10.102.105.123
  Port:         db  3306/TCP
  TargetPort:   db/TCP
  Endpoints:    172.17.0.5:3306

Database Secret:
  Name:         mysql-demo-auth
  Labels:         kubedb.com/kind=MySQL
                  kubedb.com/name=mysql-demo
  Annotations:  <none>
  
Type:  Opaque
  
Data
====
  password:  16 bytes
  user:      4 bytes

No Snapshots.

Events:
  Type    Reason      Age   From            Message
  ----    ------      ----  ----            -------
  Normal  Successful  4m    MySQL operator  Successfully created Service
  Normal  Successful  4m    MySQL operator  Successfully created StatefulSet
  Normal  Successful  4m    MySQL operator  Successfully created MySQL
  Normal  Successful  4m    MySQL operator  Successfully patched StatefulSet
  Normal  Successful  4m    MySQL operator  Successfully patched MySQL
  Normal  Successful  3m    MySQL operator  Successfully patched StatefulSet
  Normal  Successful  3m    MySQL operator  Successfully patched MySQL

kubedb describe command provides following basic information about a MySQL database.

  • StatefulSet
  • Storage (Persistent Volume)
  • Service
  • Secret (If available)
  • Snapshots (If any)
  • Monitoring system (If available)

To hide events on KubeDB object, use flag --show-events=false

To describe all MySQL objects in default namespace, use following command

kubedb describe my

To describe all MySQL objects from every namespace, provide --all-namespaces flag.

kubedb describe my --all-namespaces

To describe all KubeDB objects from every namespace, use the following command:

kubedb describe all --all-namespaces

You can also describe KubeDB objects with matching labels. The following command will describe all MySQL objects with specified labels from every namespace.

kubedb describe my --all-namespaces --selector='group=dev'

To learn about various options of describe command, please visit here.

How to Edit Objects

kubedb edit command allows users to directly edit any KubeDB object. It will open the editor defined by _KUBEDBEDITOR, or EDITOR environment variables, or fall back to nano.

Lets edit an existing running MySQL object to setup Scheduled Backup. The following command will open MySQL mysql-demo in editor.

$ kubedb edit my mysql-demo

# Add following under Spec to configure periodic backups
# backupSchedule:
#   cronExpression: '@every 1m'
#   storageSecretName: my-snap-secret
#   gcs:
#     bucket: bucket-name

mysql "mysql-demo" edited

Edit Restrictions

Various fields of a KubeDB object can’t be edited using edit command. The following fields are restricted from updates for all KubeDB objects:

  • apiVersion
  • kind
  • metadata.name
  • metadata.namespace
  • status

If StatefulSets exists for a MySQL database, following fields can’t be modified as well.

  • spec.databaseSecret
  • spec.init
  • spec.storageType
  • spec.storage
  • spec.podTemplate.spec.nodeSelector
  • spec.podTemplate.spec.env

For DormantDatabase, spec.origin can’t be edited using kubedb edit

To learn about various options of edit command, please visit here.

How to Delete Objects

kubedb delete command will delete an object in default namespace by default unless namespace is provided. The following command will delete a MySQL mysql-dev in default namespace

$ kubedb delete mysql mysql-dev
mysql.kubedb.com "mysql-dev" deleted

You can also use YAML files to delete objects. The following command will delete a mysql using the type and name specified in mysql.yaml.

$ kubedb delete -f mysql-demo.yaml
mysql.kubedb.com "mysql-dev" deleted

kubedb delete command also takes input from stdin.

cat mysql-demo.yaml | kubedb delete -f -

To delete database with matching labels, use --selector flag. The following command will delete mysql with label mysql.kubedb.com/name=mysql-demo.

kubedb delete mysql -l mysql.kubedb.com/name=mysql-demo

To learn about various options of delete command, please visit here.

Using Kubectl

You can use Kubectl with KubeDB objects like any other CRDs. Below are some common examples of using Kubectl with KubeDB objects.

# List objects
$ kubectl get mysql
$ kubectl get mysql.kubedb.com

# Delete objects
$ kubectl delete mysql <name>

Next Steps

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