Add virtual resources

config/crds/apis.kcp.io_apiexports.yaml

@@ -470,6 +470,8 @@ spec:
                       oneOf:
                       - required:
                         - crd
+                      - required:
+                        - virtual
                       properties:
                         crd:
                           description: |-
@@ -478,7 +480,48 @@ spec:
                             Like in vanilla Kubernetes, users can then create, update and delete
                             custom resources.
                           type: object
+                        virtual:
+                          description: |-
+                            Virtual storage defines that this APIResourceSchema is exposed as
+                            a projection of the referenced resource inside the workspaces that
+                            bind to the APIExport.
+                          properties:
+                            identityHash:
+                              description: IdentityHash is the identity of the virtual
+                                resource.
+                              type: string
+                            reference:
+                              description: |-
+                                Reference points to another object that has a URL to a virtual workspace
+                                in a "url" field in its status. The object can be of any kind.
+                              properties:
+                                apiGroup:
+                                  description: |-
+                                    APIGroup is the group for the resource being referenced.
+                                    If APIGroup is not specified, the specified Kind must be in the core API group.
+                                    For any other third-party types, APIGroup is required.
+                                  type: string
+                                kind:
+                                  description: Kind is the type of resource being
+                                    referenced
+                                  type: string
+                                name:
+                                  description: Name is the name of resource being
+                                    referenced
+                                  type: string
+                              required:
+                              - kind
+                              - name
+                              type: object
+                              x-kubernetes-map-type: atomic
+                          required:
+                          - identityHash
+                          - reference
+                          type: object
                       type: object
+                      x-kubernetes-validations:
+                      - message: Exactly one of crd or virtual must be set
+                        rule: has(self.crd) != has(self.virtual)
                   required:
                   - group
                   - name

config/crds/apis.kcp.io_apiexports.yaml-patch

@@ -17,6 +17,7 @@
   path: /spec/versions/name=v1alpha2/schema/openAPIV3Schema/properties/spec/properties/resources/items/properties/storage/oneOf
   value:
     - required: ["crd"]
+    - required: ["virtual"]
 
 # conversion for core resources does not happen via webhooks, but is short-circuited to the
 # schema's Convert functions directly, but the CRD still needs to define a conversion.

config/crds/cache.kcp.io_cachedresourceendpointslices.yaml

@@ -65,6 +65,11 @@ spec:
                 x-kubernetes-validations:
                 - message: CachedResource reference must not be changed
                   rule: self == oldSelf
+              partition:
+                description: |-
+                  partition points to a partition that is used for filtering the endpoints
+                  of the CachedResource part of the slice.
+                type: string
             required:
             - cachedResource
             type: object
@@ -73,6 +78,52 @@ spec:
               status communicates the observed state:
               the filtered list of endpoints for the Replication service.
             properties:
+              conditions:
+                description: conditions is a list of conditions that apply to the
+                  CachedResourceEndpointSlice.
+                items:
+                  description: Condition defines an observation of a object operational
+                    state.
+                  properties:
+                    lastTransitionTime:
+                      description: |-
+                        Last time the condition transitioned from one status to another.
+                        This should be when the underlying condition changed. If that is not known, then using the time when
+                        the API field changed is acceptable.
+                      format: date-time
+                      type: string
+                    message:
+                      description: |-
+                        A human readable message indicating details about the transition.
+                        This field may be empty.
+                      type: string
+                    reason:
+                      description: |-
+                        The reason for the condition's last transition in CamelCase.
+                        The specific API may choose whether or not this field is considered a guaranteed API.
+                        This field may not be empty.
+                      type: string
+                    severity:
+                      description: |-
+                        Severity provides an explicit classification of Reason code, so the users or machines can immediately
+                        understand the current situation and act accordingly.
+                        The Severity field MUST be set only when Status=False.
+                      type: string
+                    status:
+                      description: Status of the condition, one of True, False, Unknown.
+                      type: string
+                    type:
+                      description: |-
+                        Type of condition in CamelCase or in foo.example.com/CamelCase.
+                        Many .condition.type values are consistent across resources like Available, but because arbitrary conditions
+                        can be useful (see .node.status.conditions), the ability to deconflict is important.
+                      type: string
+                  required:
+                  - lastTransitionTime
+                  - status
+                  - type
+                  type: object
+                type: array
               endpoints:
                 description: endpoints contains all the URLs of the Replication service.
                 items:
@@ -90,6 +141,12 @@ spec:
                 x-kubernetes-list-map-keys:
                 - url
                 x-kubernetes-list-type: map
+              shardSelector:
+                description: |-
+                  shardSelector is the selector used to filter the shards. It is used to filter the shards
+                  when determining partition scope when deriving the endpoints. This is set by owning shard,
+                  and is used by follower shards to determine if its inscope or not.
+                type: string
             type: object
         type: object
     served: true

config/crds/cache.kcp.io_cachedresources.yaml

@@ -216,42 +216,6 @@ spec:
                 - cache
                 - local
                 type: object
-              resourceSchemaSource:
-                description: ResourceSchemaSource is a reference to the schema object
-                  of the cached resource.
-                properties:
-                  apiResourceSchema:
-                    description: APIResourceSchema defines an APIResourceSchema as
-                      the source of the schema.
-                    properties:
-                      clusterName:
-                        description: ClusterName is the name of the cluster where
-                          the APIResourceSchema is defined.
-                        minLength: 1
-                        type: string
-                      name:
-                        description: Name is the APIResourceSchema name.
-                        minLength: 1
-                        type: string
-                    required:
-                    - clusterName
-                    - name
-                    type: object
-                  crd:
-                    description: CRD defines a CRD as the source of the schema.
-                    properties:
-                      name:
-                        description: Name is the CRD name.
-                        minLength: 1
-                        type: string
-                      resourceVersion:
-                        description: ResourceVersion is the resource version of the
-                          source CRD object.
-                        type: string
-                    required:
-                    - name
-                    type: object
-                type: object
             type: object
         required:
         - spec

config/examples/virtualresources/README.md

@@ -0,0 +1,55 @@
+# VirtualResources Example
+
+This example shows usage of VirtualResources, together with CachedResources.
+The goal of VirtualResources is to distribute static, read-only resources to multiple clusters
+in a scalable way.
+
+## Setup
+
+1. Start kcp with sharded setup:
+
+   ```bash
+   make test-run-sharded-server
+   ```
+
+2. Create a provider workspace, where we will create the resources to be distributed:
+
+   ```bash
+   export KUBECONFIG=.kcp/admin.kubeconfig
+   kubectl ws create provider --enter
+
+   kubectl create -f config/examples/virtualresources/crd-instances.yaml
+   # this this to work we always require apiresource schema to be present
+   kubectl create -f config/examples/virtualresources/apiresourceschema-instances.yaml
+   kubectl create -f config/examples/virtualresources/instances.yaml
+
+   # create caching for the resources
+   kubectl create -f config/examples/virtualresources/cached-resource-instances.yaml
+   ```
+
+3. Create a an APIResourceSchema for actual virtual machines to be distributed,
+   which will be using instance types. 
+
+   ```bash
+    kubectl create -f config/examples/virtualresources/apiresourceschema-virtualmachine.yaml
+   ```
+
+4. Create an APIExport for the virtual machines:
+
+    ```bash
+    kubectl create -f config/examples/virtualresources/apiexport.yaml
+   ```
+
+5. Create a consumer workspace, where we will consume the virtual machines:
+
+    ```bash
+    kubectl ws use :root
+    kubectl ws create consumer --enter
+    kubectl kcp bind apiexport root:provider:virtualmachines virtualmachines
+   ```
+
+6. Now check if we can see instances in the consumer workspace:
+
+   ```bash
+   kubectl get instances.machines.svm.io
+   ```

config/examples/virtualresources/apiexport.yaml

@@ -0,0 +1,21 @@
+apiVersion: apis.kcp.io/v1alpha2
+kind: APIExport
+metadata:
+  name: virtualmachines
+spec:
+  resources:
+  - name: instances
+    group: machines.svm.io
+    schema: today.instances.machines.svm.io
+    storage:
+      virtual:
+        reference:
+          apiGroup: cache.kcp.io
+          kind: CachedResourceEndpointSlice
+          name: instances
+        identityHash: 2857921554ab76ec50f25bf083b7aeb4f7808cd169fd2945b007429f426614ec
+  - name: virtualmachines
+    group: machines.svm.io
+    schema: today.virtualmachines.machines.svm.io
+    storage:
+      crd: {}

config/examples/virtualresources/apiresourceschema-instances.yaml

@@ -0,0 +1,88 @@
+apiVersion: apis.kcp.io/v1alpha1
+kind: APIResourceSchema
+metadata:
+  name: today.instances.machines.svm.io
+spec:
+  group: machines.svm.io
+  names:
+    kind: Instance
+    listKind: InstanceList
+    plural: instances
+    singular: instance
+    shortNames:
+    - inst
+  scope: Cluster
+  versions:
+  - name: v1alpha1
+    schema:
+      description: Instance represents a virtual machine instance
+      properties:
+        apiVersion:
+          description: 'APIVersion defines the versioned schema of this representation
+            of an object. Servers should convert recognized schemas to the latest
+            internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
+          type: string
+        kind:
+          description: 'Kind is a string value representing the REST resource this
+            object represents. Servers may infer this from the endpoint the client
+            submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds'
+          type: string
+        metadata:
+          type: object
+        spec:
+          description: InstanceSpec holds the desired state of the Instance.
+          properties:
+            instanceType:
+              description: The type of the instance (e.g. small, medium, large)
+              type: string
+            name:
+              description: The name of the instance
+              type: string
+            tier:
+              description: The tier of the instance (e.g. basic, premium)
+              type: string
+              enum:
+              - basic
+              - premium
+              - enterprise
+          required:
+          - instanceType
+          - name
+          - tier
+          type: object
+        status:
+          description: InstanceStatus communicates the observed state of the Instance.
+          properties:
+            phase:
+              description: The current phase of the instance
+              type: string
+              enum:
+              - Pending
+              - Running
+              - Terminated
+            conditions:
+              description: Current conditions of the instance
+              items:
+                properties:
+                  type:
+                    type: string
+                  status:
+                    type: string
+                  lastTransitionTime:
+                    type: string
+                    format: date-time
+                  reason:
+                    type: string
+                  message:
+                    type: string
+                required:
+                - type
+                - status
+                type: object
+              type: array
+          type: object
+      type: object
+    served: true
+    storage: true
+    subresources:
+      status: {}