Add sharding to API docs

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

README.md

@@ -18,9 +18,9 @@ removes the operational burden of managing Flux across fleets of clusters by ful
 installation, configuration, and upgrade of the Flux controllers based on a declarative API.
 
 **Advanced Configuration** - The operator simplifies the configuration of Flux multi-tenancy lockdown,
-vertical scaling, persistent storage, and allows fine-tuning the Flux controllers with Kustomize patches.
-The operator streamlines the transition from Git as the delivery mechanism for the cluster
-desired state to OCI artifacts and S3-compatible storage.
+sharding, horizontal and vertical scaling, persistent storage, and allows fine-tuning the Flux
+controllers with Kustomize patches. The operator streamlines the transition from Git as the delivery
+mechanism for the cluster desired state to OCI artifacts and S3-compatible storage.
 
 **Deep Insights** - The operator provides deep insights into the delivery pipelines managed by Flux,
 including detailed reports and Prometheus metrics about the Flux controllers

api/v1/fluxinstance_types.go

@@ -79,7 +79,7 @@ type FluxInstanceSpec struct {
 	// and Flux Kustomization are created to sync the cluster state
 	// with the source repository.
 	// +optional
-	Sync *Sync `json:"sync"`
+	Sync *Sync `json:"sync,omitempty"`
 }
 
 // Distribution specifies the version and container registry to pull images from.

config/olm/bundle/manifests/flux-operator.clusterserviceversion.yaml

@@ -111,8 +111,7 @@ metadata:
 spec:
   displayName: Flux Operator
   description: >-
-    [Flux](https://fluxcd.io) is a leading GitOps Continuous Delivery
-    tool
+    [Flux](https://fluxcd.io) is a leading GitOps Continuous Delivery tool
     used to streamline and automate application deployments on Kubernetes.
     Flux enables teams to achieve a reliable and auditable delivery process
     while promoting collaboration and traceability across different environments.
@@ -125,17 +124,15 @@ spec:
     For more information about the CNCF-graduated Flux project, please see
     the [Flux architecture overview](https://fluxcd.control-plane.io/guides/flux-architecture/).
 
-
     ### Operator Capabilities
 
-
     The [Flux Operator](https://github.com/controlplaneio-fluxcd/flux-operator) provides a
     declarative API for the installation, configuration and upgrade of CNCF Flux
     and the ControlPlane [enterprise distribution](https://fluxcd.control-plane.io/).
 
     The operator allows the configuration of Flux multi-tenancy lockdown, network policies,
-    persistent storage, vertical scaling, custom patches, and the synchronization of the
-    cluster state from Git repositories, OCI artifacts and S3-compatible storage.
+    persistent storage, sharding, vertical scaling, custom patches, and the synchronization
+    of the cluster state from Git repositories, OCI artifacts and S3-compatible storage.
 
     The Flux Operator supervises the Flux controllers and provides a unified view
     of all the Flux resources that define the GitOps workflows for the target cluster.
@@ -144,7 +141,6 @@ spec:
 
     ### OpenShift Support
 
-
     The Flux Operator should be installed in a dedicated namespace, e.g. `flux-system`.
 
     To deploy Flux on OpenShift clusters, create a `FluxInstance` custom resource

docs/api/v1/fluxinstance.md

@@ -330,6 +330,52 @@ spec:
 
 The `.spec.storage.size` field is required and specifies the size of the persistent volume claim.
 
+### Sharding configuration
+
+The `.spec.sharding` field is optional and specifies the sharding configuration for the Flux controllers.
+
+Example:
+
+```yaml
+spec:
+  sharding:
+    key: "sharding.fluxcd.io/key"
+    shards:
+      - "shard1"
+      - "shard2"
+```
+
+For each shard, the operator will create a separate set of controllers, e.g.:
+
+```console
+$ kubectl -n flux-system get deployments -l app.kubernetes.io/part-of=flux
+NAME
+source-controller
+source-controller-shard1
+source-controller-shard2
+kustomize-controller
+kustomize-controller-shard1
+kustomize-controller-shard2
+helm-controller
+helm-controller-shard1
+helm-controller-shard2
+```
+
+Note that only the `source-controller`, `kustomize-controller` and `helm-controller` controllers
+support sharding.
+
+To assign a resource to a specific shard, add the `sharding.fluxcd.io/key` label with the shard value,
+e.g.: `sharding.fluxcd.io/key: shard1`.
+
+#### Sharding key
+
+The `.spec.sharding.key` field is optional and specifies the sharding key label to use for the Flux controllers.
+By default, the key is set to `sharding.fluxcd.io/key`.
+
+#### Shards
+
+The `.spec.sharding.shards` field is required and specifies the list of sharding values to use for the Flux controllers.
+
 ### Kustomize patches
 
 The `.spec.kustomize.patches` field is optional and specifies the Kustomize patches to apply to the Flux controllers.