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FerretDBVersion
What is FerretDBVersion
FerretDBVersion is a Kubernetes Custom Resource Definitions (CRD). It provides a declarative configuration to specify the docker images to be used for FerretDB server deployed with KubeDB in a Kubernetes native way.
When you install KubeDB, a FerretDBVersion custom resource will be created automatically for every supported FerretDB release versions. You have to specify the name of FerretDBVersion crd in spec.version field of FerretDB crd. Then, KubeDB will use the docker images specified in the FerretDBVersion crd to create your expected FerretDB instance.
Using a separate crd for specifying respective docker image names allow us to modify the images independent of KubeDB operator. This will also allow the users to use a custom FerretDB image for their server.
FerretDBVersion Specification
As with all other Kubernetes objects, a FerretDBVersion needs apiVersion, kind, and metadata fields. It also needs a .spec section.
apiVersion: catalog.kubedb.com/v1alpha1
kind: FerretDBVersion
metadata:
name: 1.23.0
spec:
db:
image: ghcr.io/appscode-images/ferretdb:1.23.0
securityContext:
runAsUser: 1000
version: 1.23.0
deprecated: false
metadata.name
metadata.name is a required field that specifies the name of the FerretDBVersion crd. You have to specify this name in spec.version field of FerretDB crd.
We follow this convention for naming FerretDBVersion crd:
- Name format:
{Original ferretdb image version}-{modification tag}
We plan to modify original FerretDB docker images to support additional features. Re-tagging the image with v1, v2 etc. modification tag help separating newer iterations from the older ones. An image with higher modification tag will have more features than the images with lower modification tag. Hence, it is recommended to use FerretDBVersion crd with higher modification tag to take advantage of the latest features.
spec.version
spec.version is a required field that specifies the original version of FerretDB that has been used to build the docker image specified in spec.server.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 true, KubeDB operator will not create the server and other respective resources for this version.
spec.ferretdb.image
spec.ferretdb.image is a required field that specifies the docker image which will be used to create PetSet by KubeDB operator to create expected FerretDB server.
spec.securityContext
spec.securityContext holds pod-level security attributes and common container settings for FerretDB pod.