Create a database cluster from a template¶

Database clusters can be created from templates using PMM. Templates allow you to customize the creation of database clusters. You can adapt templates to tweak K8s-specific settings such as liveness probes, changing config maps, or tuning database engines.

Create Custom Resource Definition (CRD) template¶

To create a template, do the following:

Note

The example below shows how to change the upgradeOptions field, but it would be different if you wanted to customize some other field.

Identify the fields of interest by reading the operator documentation and corresponding CRDs. In this case, updateStrategy and upgradeOptions fields as per the PXC operator documentation and PXC CRD.
Create a template CRD pxctpl-crd-upgrade-options.yaml with the fields of interest as follows:

Note

Template CRDs must have an openAPIV3Schema that must be a subset of the parent engine CRD. For this case, the parent engine CRD is this.

apiVersion: apiextensions.k8s.io/v1
    kind: CustomResourceDefinition
    metadata:
    creationTimestamp: null
    name: pxctemplateupgradeoptions.dbaas.percona.com
    labels:
        dbaas.percona.com/template: "yes"
        dbaas.percona.com/engine: "pxc"
    spec:
    group: dbaas.percona.com
    names:
        kind: PXCTemplateUpgradeOptions
        listKind: PXCTemplateUpgradeOptionsList
        plural: pxctemplateupgradeoptions
        singular: pxctemplateupgradeoptions
    scope: Namespaced
    versions:
    - name: v1
        schema:
        openAPIV3Schema:
            properties:
            apiVersion:
                type: string
            kind:
                type: string
            metadata:
                type: object
            spec:
                properties:
                updateStrategy:
                    type: string
                upgradeOptions:
                    properties:
                    apply:
                        type: string
                    schedule:
                        type: string
                    versionServiceEndpoint:
                        type: string
                    type: object
                type: object
            status:
                type: object
            type: object
        served: true
        storage: true

Run the following command:
```
$ kubectl apply -f pxctpl-crd-upgrade-options.yaml
```
For more information, see DatabaseCluster templates.

Add Read permissions for pxctemplateupgradeoptions¶

For the dbaas-operator to apply the template it needs access to the template CRs.

$ DBAAS_OPERATOR_MANAGER_ROLE=$(kubectl get clusterroles | grep dbaas-operator | grep -v metrics | grep -v proxy | cut -f 1 -d ' '); kubectl get clusterroles/"$DBAAS_OPERATOR_MANAGER_ROLE" -o yaml > dbaas-operator-manager-role.yaml

$ cat <<EOF >>dbaas-operator-manager-role.yaml
- apiGroups:
  - dbaas.percona.com
  resources:
  - pxctemplateupgradeoptions
  verbs:
  - get
  - list
EOF

Run the following command to apply the configuration:

$ kubectl apply -f dbaas-operator-manager-role.yaml

Create Custom Resources (CR) template¶

Create the CR pxctpl-disable-automatic-upgrades.yaml file with the desired values as follows:

apiVersion: dbaas.percona.com/v1
kind: PXCTemplateUpgradeOptions
metadata:
name: disable-automatic-upgrades
labels:
    dbaas.percona.com/template: "yes"
    dbaas.percona.com/engine: "pxc"
spec:
updateStrategy: SmartUpdate
upgradeOptions:
    apply: Disabled

Run the following command:

$ kubectl apply -f pxctpl-disable-automatic-upgrades.yaml

pxctemplateupgradeoptions.dbaas.percona.com/disable-automatic-upgrades created

Create a DB cluster from template¶

To create a DB cluster from a template, do the following:

From the main menu navigate to DBaaS → Create DB Cluster.
On the Advanced Settings panel, select the template from the Templates drop-down.
Click Create.

Last update: 2023-03-30