Supported Resource Types

The Operator supports the following resource types (known as Kind's):

KurrentDB
KurrentDBBackup
KurrentDBBackupSchedule

KurrentDB

This resource type is used to define a database deployment.

API

KurrentDBSpec

Field	Required	Description
`replicas` integer	Yes	Number of nodes in a database cluster. May be 1, 3, or, for standalone ReadOnly-Replicas, it may be 0.
`image` string	Yes	KurrentDB container image URL
`resources` ResourceRequirements	No	Database container resource limits and requests
`storage` PersistentVolumeClaim	Yes	Persistent volume claim settings for the underlying data volume
`network` KurrentDBNetwork	Yes	Defines the network configuration to use with the database
`configuration` yaml	No	Additional configuration to use with the database, see below
`sourceBackup` string	No	Backup name to restore a cluster from
`security` KurrentDBSecurity	No	Security configuration to use for the database. This is optional, if not specified the cluster will be created without security enabled.
`licenseSecret` SecretKeySelector	No	A secret that contains the Enterprise license for the database
`constraints` KurrentDBConstraints	No	Scheduling constraints for the Kurrent DB pod.
`readOnlyReplias` KurrentDBReadOnlyReplicasSpec	No	Read-only replica configuration the Kurrent DB Cluster.
`extraMetadata` KurrentDBExtraMetadataSpec	No	Additional annotations and labels for child resources.
`quorumNodes` string array	No	A list of endpoints (in host:port notation) to reach the quorum nodes when .Replicas is zero, see standalone ReadOnlyReplicas

KurrentDBReadOnlyReplicasSpec

Other than replicas, each of the fields in KurrentDBReadOnlyReplicasSpec default to the corresponding values from the main KurrentDBSpec.

Field	Required	Description
`replicas` integer	No	Number of read-only replicas in the cluster. Defaults to zero.
`resources` ResourceRequirements	No	Database container resource limits and requests.
`storage` PersistentVolumeClaim	No	Persistent volume claim settings for the underlying data volume.
`configuration` yaml	No	Additional configuration to use with the database.
`constraints` KurrentDBConstraints	No	Scheduling constraints for the Kurrent DB pod.

KurrentDBConstraints

Field	Required	Description
`nodeSelector` yaml	No	Identifies nodes that the Kurrent DB may consider during scheduling.
`affinity` Affinity	No	The node affinity, pod affinity, and pod anti-affinity for scheduling the Kurrent DB pod.
`tolerations` list of Toleration	No	The tolerations for scheduling the Kurrent DB pod.
`topologySpreadConstraints` list of TopologySpreadConstraint	No	The topology spread constraints for scheduling the Kurrent DB pod.

KurrentDBExtraMetadataSpec

Field	Required	Description
`all` ExtraMetadataSpec	No	Extra annotations and labels for all child resource types.
`configMaps` ExtraMetadataSpec	No	Extra annotations and labels for ConfigMaps.
`statefulSets` ExtraMetadataSpec	No	Extra annotations and labels for StatefulSets.
`pods` ExtraMetadataSpec	No	Extra annotations and labels for Pods.
`persistentVolumeClaims` ExtraMetadataSpec	No	Extra annotations and labels for PersistentVolumeClaims.
`headlessServices` ExtraMetadataSpec	No	Extra annotations and labels for the per-cluster headless Services.
`headlessPodServices` ExtraMetadataSpec	No	Extra annotations and labels for the per-pod headless Services.
`loadBalancers` ExtraMetadataSpec	No	Extra annotations and labels for LoadBalancer-type Services.

Note that select kinds of extra metadata support template expansion to allow multiple instances of a child resource to be distinguished from one another. In particular, ConfigMaps, StatefulSets, and HeadlessServices support "per-node-kind" template expansions:

{name} expands to KurrentDB.metadata.name
{namespace} expands to KurretnDB.metadata.namespace
{domain} expands to the KurrnetDBNetwork.domain
{nodeTypeSuffix} expands to "" for a primary node or "-replica" for a replica node

Additionally, HeadlessPodServices and LoadBalancers support "per-pod" template expansions:

{name} expands to KurrentDB.metadata.name
{namespace} expands to KurretnDB.metadata.namespace
{domain} expands to the KurrnetDBNetwork.domain
{nodeTypeSuffix} expands to "" for a primary node or "-replica" for a replica node
{podName} expands to the name of the pod corresponding to the resource
{podOrdinal} the ordinal assigned to the pod corresponding to the resource

Notably, Pods and PersistentVolumeClaims do not support any template expansions, due to how StatefulSets work.

ExtraMetadataSpec

Field	Required	Description
`labels` object	No	Extra labels for a resource.
`annotations` object	No	Extra annotations for a resource.

KurrentDBNetwork

Field	Required	Description
`domain` string	Yes	Domain used for external DNS e.g. advertised address exposed in the gossip state
`loadBalancer` KurrentDBLoadBalancer	Yes	Defines a load balancer to use with the database
`fqdnTemplate` string	No	The template string used to define the external advertised address of a node
`internodeTrafficStrategy` string	No	How servers dial each other. One of `"ServiceName"` (default), `"FQDN"`, or `"SplitDNS"`. See details.
`clientTrafficStrategy` string	No	How clients dial servers. One of `"ServiceName"` or `"FQDN"` (default). See details.
`splitDNSExtraRules` list of DNSRule	No	Advanced configuration for when `internodeTrafficStrategy` is set to `"SplitDNS"`.

Note that fqdnTemplate supports the following expansions:

{name} expands to KurrentDB.metadata.name
{namespace} expands to KurretnDB.metadata.namespace
{domain} expands to the KurrnetDBNetwork.domain
{nodeTypeSuffix} expands to "" for a primary node or "-replica" for a replica node
{podName} expands to the name of the pod

When fqdnTemplate is empty, it defaults to {podName}.{name}{nodeTypeSuffix}.{domain}.

DNSRule

Field	Required	Description
`host` string	Yes	A host name that should be intercepted.
`result` string	Yes	An IP address to return, or another hostname to look up for the final IP address.
`regex` boolean	No	Whether `host` and `result` should be treated as regex patterns. Defaults to `false`.

Note that when regex is true, the regex support is provided by the go standard regex library, and referencing captured groups differs from some other regex implementations. For example, to redirect lookups matching the pattern

    <podname>.my-db.my-namespace.svc.cluster.local

    <podname>.my-domain.com

you could use the following dns rule:

host: ([a-z0-9-]*)\.my-db\.my-namespace\.svc\.cluster\.local
result: ${1}.my-domain.com
regex: true

KurrentDBLoadBalancer

Field	Required	Description
`enabled` boolean	Yes	Determines if a load balancer should be deployed for each node
`allowedIps` string array	No	List of IP ranges allowed by the load balancer (default will allow all access)

KurrentDBSecurity

Field	Required	Description
`certificateReservedNodeCommonName` string	No	Common name for the TLS certificate (this maps directly to the database property `CertificateReservedNodeCommonName`)
`certificateAuthoritySecret` CertificateSecret	No	Secret containing the CA TLS certificate.
`certificateSecret` CertificateSecret	Yes	Secret containing the TLS certificate to use.
`certificateSubjectName` string	No	Deprecated field. The value of this field is always ignored.

CertificateSecret

Field	Required	Description
`name` string	Yes	Name of the secret holding the certificate details
`keyName` string	Yes	Key within the secret containing the TLS certificate
`privateKeyName` string	No	Key within the secret containing the TLS certificate private key

KurrentDBBackup

This resource type is used to define a backup for an existing database deployment.

Important

Resources of this type must be created within the same namespace as the target database cluster to backup.

API

KurrentDBBackupSpec

Field	Required	Description
`clusterName` string	Yes	Name of the source database cluster
`nodeName` string	No	Specific node name within the database cluster to use as the backup. If unspecified, the leader is used.
`volumeSnapshotClassName` string	Yes	The name of the underlying volume snapshot class to use.
`extraMetadata` KurrentDBBackupExtraMetadataSpec	No	Additional annotations and labels for child resources.
`ttl` string	No	A time-to-live for this backup. If unspecified, the TTL is treated as infinite.

The format of the ttl may be in years (y), weeks (w), days (d), hours (h), or seconds (s), or a combination like 1d12h

KurrentDBBackupExtraMetadataSpec

Field	Required	Description
All ExtraMetadataSpec	No	Extra annotations and labels for all child resource types (currently only VolumeSnapshots).
VolumeSnapshots ExtraMetadataSpec	No	Extra annotations and labels for VolumeSnapshots.

KurrentDBBackupSchedule

This resource type is used to define a schedule for creating database backups and retention policies.

KurrentDBBackupScheduleSpec

Field	Required	Description
`schedule` string	Yes	A CronJob-style schedule. See Writing a CronJob Spec.
`timeZone` string	No	A timezone specification. Defaults to `Etc/UTC`.
`template` KurrentDBBackup	Yes	A `KurrentDBBackup` template.
`keep` integer	No	The maximum of complete backups this schedule will accumulate before it prunes the oldes ones. If unset, there is no limit.
`suspend` boolean	No

Note that the only metadata allowed in template.metadata is name, labels, and annotations. If name is provided, it will be extended with an index like my-name-1 when creating backups, otherwise created backups will be based on the name of the schedule resource.

Configuring Kurrent DB

The KurrentDB.spec.configuration yaml field may contain any valid configuration values for Kurrent DB. However, some values may be unnecessary, as the Operator provides some defaults, while other values may be ignored, as the Operator may override them.

The Operator-defined default configuration values, which may be overridden by the user's KurrentDB.spec.configuration are:

Default Field	Default Value
DisableLogFile	true
EnableAtomPubOverHTTP	true
Insecure	false
PrepareTimeoutMs	3000
CommitTimeoutMs	3000
GossipIntervalMs	2000
GossipTimeoutMs	5000
LeaderElectionTimeoutMs	2000
ReplicationHeartbeatInterval	1000
ReplicationHeartbeatTimeout	2500
NodeHeartbeatInterval	1000
NodeHeartbeatTimeout	2500

The Operator-managed configuration values, which take precedence over the user's KurrentDB.spec.configuration, are:

Managed Field	Value
Db	hard-coded volume mount point
Index	hard-coded volume mount point
Log	hard-coded volume mount point
Insecure	true if `KurrentDB.spec.security.certificateSecret` is empty
DiscoverViaDns	false (`GossipSeed` is used instead)
AllowAnonymousEndpointAccess	true
AllowUnknownOptions	true
NodeIp	0.0.0.0 (to accept traffic from outside pod)
ReplicationIp	0.0.0.0 (to accept traffic from outside pod)
NodeHostAdvertiseAs	Derived from pod name
ReplicationHostAdvertiseAs	Derived from pod name
AdveritseHostToClientAs	Derived from `KurrentDB.spec.newtork.fqdnTemplate`
ClusterSize	Derived from `KurrentDB.spec.replicas`
GossipSeed	Derived from pod list
ReadOnlyReplica	Automatically set for ReadOnlyReplica pods