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MariaDBOpsRequest

What is MariaDBOpsRequest

MariaDBOpsRequest is a Kubernetes Custom Resource Definitions (CRD). It provides a declarative configuration for MariaDB administrative operations like database version updating, horizontal scaling, vertical scaling etc. in a Kubernetes native way.

MariaDBOpsRequest CRD Specifications

Like any official Kubernetes resource, a MariaDBOpsRequest has TypeMeta, ObjectMeta, Spec and Status sections.

Here, some sample MariaDBOpsRequest CRs for different administrative operations is given below:

Sample MariaDBOpsRequest for updating database:

apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
  name: mdops-update
  namespace: demo
spec:
  type: UpdateVersion
  databaseRef:
    name: sample-mariadb
  updateVersion:
    targetVersion: 10.5.8
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample MariaDBOpsRequest Objects for Horizontal Scaling of database cluster:

apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
  name: mdps-scale-horizontal
  namespace: demo
spec:
  type: HorizontalScaling
  databaseRef:
    name: sample-mariadb
  horizontalScaling:
    member : 5
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample MariaDBOpsRequest Objects for Vertical Scaling of the database cluster:

apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
  name: md-scale-vertical
  namespace: demo
spec:
  type: VerticalScaling  
  databaseRef:
    name: sample-mariadb
  verticalScaling:
    mariadb:
      requests:
        memory: "600Mi"
        cpu: "0.1"
      limits:
        memory: "600Mi"
        cpu: "0.1"
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample MariaDBOpsRequest Objects for Reconfiguring MariaDB Database:

apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
  name: md-reconfigure
  namespace: demo
spec:
  type: Reconfigure
  databaseRef:
    name: sample-mariadb
  configuration:   
    inlineConfig: |
      max_connections = 300
      read_buffer_size = 1234567      
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample MariaDBOpsRequest Objects for Volume Expansion of MariaDB:

apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
  name: md-volume-expansion
  namespace: demo
spec:
  type: VolumeExpansion  
  databaseRef:
    name: sample-mariadb
  volumeExpansion:   
    mode: "Online"
    mariadb: 2Gi
status:
  conditions:
    - lastTransitionTime: "2020-08-25T18:22:38Z"
      message: Successfully completed the modification process
      observedGeneration: 1
      reason: Successful
      status: "True"
      type: Successful
  observedGeneration: 1
  phase: Successful

Sample MariaDBOpsRequest Objects for Reconfiguring TLS of the database:

apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
  name: md-recon-tls-add
  namespace: demo
spec:
  type: ReconfigureTLS
  databaseRef:
    name: sample-mariadb
  tls:
    requireSSL: true
    issuerRef:
      apiGroup: cert-manager.io
      kind: Issuer
      name: md-issuer
    certificates:
    - alias: server
      subject:
        organizations:
        - kubedb:server
      dnsNames:
      - localhost
      ipAddresses:
      - "127.0.0.1"

apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
  name: md-recon-tls-rotate
  namespace: demo
spec:
  type: ReconfigureTLS
  databaseRef:
    name: sample-mariadb
  tls:
    rotateCertificates: true

Here, we are going to describe the various sections of a MariaDBOpsRequest crd.

A MariaDBOpsRequest object has the following fields in the spec section.

spec.databaseRef

spec.databaseRef is a required field that point to the MariaDB object for which the administrative operations will be performed. This field consists of the following sub-field:

• spec.databaseRef.name : specifies the name of the MariaDB object.

spec.type

spec.type specifies the kind of operation that will be applied to the database. Currently, the following types of operations are allowed in MariaDBOpsRequest.

• Upgrade / UpdateVersion
• HorizontalScaling
• VerticalScaling
• VolumeExpansion
• Reconfigure
• ReconfigureTLS
• Restart

You can perform only one type of operation on a single MariaDBOpsRequest CR. For example, if you want to update your database and scale up its replica then you have to create two separate MariaDBOpsRequest. At first, you have to create a MariaDBOpsRequest for updating. Once it is completed, then you can create another MariaDBOpsRequest for scaling. You should not create two MariaDBOpsRequest simultaneously.

spec.updateVersion

If you want to update your MariaDB version, you have to specify the spec.updateVersion section that specifies the desired version information. This field consists of the following sub-field:

• spec.updateVersion.targetVersion refers to a MariaDBVersion CR that contains the MariaDB version information where you want to update.

You can only update between MariaDB versions. KubeDB does not support downgrade for MariaDB.

spec.horizontalScaling

If you want to scale-up or scale-down your MariaDB cluster or different components of it, you have to specify spec.horizontalScaling section. This field consists of the following sub-field:

• spec.horizontalScaling.member indicates the desired number of nodes for MariaDB cluster after scaling. For example, if your cluster currently has 4 nodes, and you want to add additional 2 nodes then you have to specify 6 in spec.horizontalScaling.member field. Similarly, if you want to remove one node from the cluster, you have to specify 3 in spec.horizontalScaling. field.

spec.verticalScaling

spec.verticalScaling is a required field specifying the information of MariaDB resources like cpu, memory etc that will be scaled. This field consists of the following sub-field:

• spec.verticalScaling.mariadb indicates the desired resources for MariaDB standalone or cluster after scaling.
• spec.verticalScaling.exporter indicates the desired resources for the exporter container.
• spec.verticalScaling.coordinator indicates the desired resources for the coordinator container.

All of them has the below structure:

requests:
  memory: "200Mi"
  cpu: "0.1"
limits:
  memory: "300Mi"
  cpu: "0.2"

Here, when you specify the resource request, the scheduler uses this information to decide which node to place the container of the Pod on and when you specify a resource limit for the container, the kubelet enforces those limits so that the running container is not allowed to use more of that resource than the limit you set. You can found more details from here.

spec.volumeExpansion

To use the volume expansion feature the storage class must support volume expansion

If you want to expand the volume of your MariaDB standalone or cluster, you have to specify spec.volumeExpansion section. This field consists of the following sub-field:

• spec.volumeExpansion.mariadb indicates the desired size for the persistent volume of a MariaDB.
• spec.volumeExpansion.mode indicates the mode of volume expansion. It can be online or offline based on the storage class.

All of them refer to Quantity types of Kubernetes.

Example usage of this field is given below:

spec:
  volumeExpansion:
    mariadb: "2Gi"

This will expand the volume size of all the mariadb nodes to 2 GB.

spec.configuration

If you want to reconfigure your Running MariaDB cluster with new custom configuration, you have to specify spec.configuration section. This field consists of the following sub-fields:

• configSecret points to a secret in the same namespace of a MariaDB resource, which contains the new custom configurations. If there are any configSecret set before in the database, this secret will replace it.
• inlineConfig contains the new custom config as a string which will be merged with the previous configuration.
• removeCustomConfig reomoves all the custom configs of the MariaDB server.

spec.tls

If you want to reconfigure the TLS configuration of your database i.e. add TLS, remove TLS, update issuer/cluster issuer or Certificates and rotate the certificates, you have to specify spec.tls section. This field consists of the following sub-field:

• spec.tls.issuerRef specifies the issuer name, kind and api group.
• spec.tls.certificates specifies the certificates. You can learn more about this field from here.
• spec.tls.rotateCertificates specifies that we want to rotate the certificate of this database.
• spec.tls.remove specifies that we want to remove tls from this database.

MariaDBOpsRequest Status

.status describes the current state and progress of a MariaDBOpsRequest operation. It has the following fields:

status.phase

status.phase indicates the overall phase of the operation for this MariaDBOpsRequest. It can have the following three values:

status.observedGeneration

status.observedGeneration shows the most recent generation observed by the MariaDBOpsRequest controller.

status.conditions

status.conditions is an array that specifies the conditions of different steps of MariaDBOpsRequest processing. Each condition entry has the following fields:

• types specifies the type of the condition. MariaDBOpsRequest has the following types of conditions:

• The status field is a string, with possible values True, False, and Unknown.
  • status will be True if the current transition succeeded.
  • status will be False if the current transition failed.
  • status will be Unknown if the current transition was denied.
• The message field is a human-readable message indicating details about the condition.
• The reason field is a unique, one-word, CamelCase reason for the condition’s last transition.
• The lastTransitionTime field provides a timestamp for when the operation last transitioned from one state to another.
• The observedGeneration shows the most recent condition transition generation observed by the controller.