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SingleStoreVersion

What is SingleStoreVersion

SingleStoreVersion is a Kubernetes Custom Resource Definitions (CRD). It provides a declarative configuration to specify the docker images to be used for SingleStore database deployed with KubeDB in a Kubernetes native way.

When you install KubeDB, a SingleStoreVersion custom resource will be created automatically for every supported SingleStore versions. You have to specify the name of SingleStoreVersion crd in spec.version field of SingleStore crd. Then, KubeDB will use the docker images specified in the SingleStoreVersion crd to create your expected database.

Using a separate crd for specifying respective docker images, and pod security policy names allow us to modify the images, and policies independent of KubeDB operator.This will also allow the users to use a custom image for the database.

SingleStoreVersion Spec

As with all other Kubernetes objects, a SingleStoreVersion needs apiVersion, kind, and metadata fields. It also needs a .spec section.

apiVersion: catalog.kubedb.com/v1alpha1
kind: SinglestoreVersion
metadata:
  name: 8.7.10
spec:
  coordinator:
    image: ghcr.io/kubedb/singlestore-coordinator:v0.3.0
  db:
    image: ghcr.io/appscode-images/singlestore-node:alma-8.7.10-95e2357384
  initContainer:
    image: ghcr.io/kubedb/singlestore-init:8.7.10-v1
  securityContext:
    runAsGroup: 998
    runAsUser: 999
  standalone:
    image: singlestore/cluster-in-a-box:alma-8.7.10-95e2357384-4.1.0-1.17.14
  updateConstraints:
    allowlist:
      - '> 8.7.10, <= 8.7.10'
  version: 8.7.10

metadata.name

metadata.name is a required field that specifies the name of the SingleStoreVersion crd. You have to specify this name in spec.version field of SingleStore crd.

We follow this convention for naming SingleStoreVersion crd:

  • Name format: {Original SingleStore image verion}-{modification tag}

We modify original SingleStore docker image to support SingleStore clustering and re-tag the image with v1, v2 etc. modification tag. An image with higher modification tag will have more features than the images with lower modification tag. Hence, it is recommended to use SingleStoreVersion crd with highest modification tag to enjoy the latest features.

spec.version

spec.version is a required field that specifies the original version of SingleStore database that has been used to build the docker image specified in spec.db.image field.

spec.deprecated

spec.deprecated is an optional field that specifies whether the docker images specified here is supported by the current KubeDB operator.

The default value of this field is false. If spec.deprecated is set to true, KubeDB operator will skip processing this CRD object and will add a event to the CRD object specifying that the DB version is deprecated.

spec.db.image

spec.db.image is a required field that specifies the docker image which will be used to create Petset by KubeDB operator to create expected SingleStore database.

spec.coordinator.image

spec.coordinator.image is a required field that specifies the docker image which will be used to create Petset by KubeDB operator to create expected SingleStore database.

spec.initContainer.image

spec.initContainer.image is a required field that specifies the image for init container.

spec.updateConstraints

updateConstraints specifies the constraints that need to be considered during version update. Here allowList contains the versions those are allowed for updating from the current version. An empty list of AllowList indicates all the versions are accepted except the denyList. On the other hand, DenyList contains all the rejected versions for the update request. An empty list indicates no version is rejected.

spec.podSecurityPolicies.databasePolicyName

spec.podSecurityPolicies.databasePolicyName is a required field that specifies the name of the pod security policy required to get the database server pod(s) running.

helm upgrade -i kubedb oci://ghcr.io/appscode-charts/kubedb \
  --namespace kubedb --create-namespace \
  --set additionalPodSecurityPolicies[0]=custom-db-policy \
  --set additionalPodSecurityPolicies[1]=custom-snapshotter-policy \
  --set-file global.license=/path/to/the/license.txt \
  --wait --burst-limit=10000 --debug

Next Steps

  • Learn about SingleStore crd here.
  • Deploy your first SingleStore database with KubeDB by following the guide here.