Merge pull request #3 from xrstf/waiter

Add initialization.kcp.io/wait-for-ready annotation

Author: kcp-ci-bot

docs/content/.pages

@@ -2,6 +2,7 @@ nav:
   - Documentation:
       - README.md
       - setup.md
+      - readiness.md
       - faq.md
   - Init Sources: init-sources
   - Reference: reference

docs/content/readiness.md

@@ -0,0 +1,100 @@
+# Waiting for Readiness
+
+In some scenarios, simply creating objects during initialization is not enough. You may need to wait for
+certain resources to become ready before the init-agent marks the workspace as initialized. For example,
+a CRD must be `Established` before custom resources using it can be created by other initializers
+further down the chain.
+
+The `initialization.kcp.io/wait-for-ready` annotation allows you to express this requirement on
+individual manifests.
+
+## How It Works
+
+When the init-agent encounters a manifest (from any of its [init sources](./init-sources/)) with
+the `initialization.kcp.io/wait-for-ready` annotation, it will:
+
+1. Create (or confirm the existence of) the object as usual.
+2. Re-fetch the object's current state from the API server.
+3. Check whether the condition type specified in the annotation's value has `status: "True"` in the
+   object's `status.conditions` list.
+4. If the condition is not yet `True`, the agent requeues reconciliation and tries again after a few
+   seconds.
+5. Only once **all** annotated objects across **all** sources have their required conditions met will
+   the agent remove the initializer from the workspace, completing initialization.
+
+The annotation value must be the **name of a condition type** (e.g. `Established`, `Ready`,
+`Available`). This condition must appear in the standard Kubernetes `status.conditions` array of
+the resource.
+
+!!! warning "Important"
+    Waiting for a condition to become `True` inherently means that **some process must set that
+    condition**. In some cases this happens automatically (e.g. the Kubernetes API server sets
+    `Established` on CRDs), but in other cases you may need a dedicated controller or operator to
+    act on the resource and update its status.
+
+    Due to the nature of kcp's workspace initialization, the workspace is not accessible through
+    the regular API while it still has initializers. Only processes that work through the same
+    `initializingworkspaces` virtual workspace – i.e. processes that are registered for the **same
+    initializer** as the init-agent – can see and modify objects in the workspace during
+    initialization.
+
+    This means that if you need an external controller to make a resource "ready", that controller
+    must also operate on the same initializer's `initializingworkspaces` view. Without this, the
+    controller will not be able to access the workspace and therefore cannot set the condition the
+    init-agent is waiting for. The initialization would be stuck indefinitely.
+
+    In practice, this is most relevant for custom operators that need to reconcile resources created
+    by the init-agent. Make sure these operators have the appropriate kcp permissions and are
+    configured to watch the same initializing workspaces.
+
+## Usage
+
+Add the annotation to any manifest inside an `InitTemplate`'s `spec.template`. The following example
+creates a CRD and waits for it to become `Established` before initialization is considered complete:
+
+```yaml
+apiVersion: initialization.kcp.io/v1alpha1
+kind: InitTemplate
+metadata:
+  name: widgets-crd
+spec:
+  template: |
+    apiVersion: apiextensions.k8s.io/v1
+    kind: CustomResourceDefinition
+    metadata:
+      name: widgets.example.com
+      annotations:
+        initialization.kcp.io/wait-for-ready: "Established"
+    spec:
+      group: example.com
+      names:
+        kind: Widget
+        listKind: WidgetList
+        plural: widgets
+        singular: widget
+      scope: Cluster
+      versions:
+        - name: v1alpha1
+          served: true
+          storage: true
+          schema:
+            openAPIV3Schema:
+              type: object
+```
+
+In this example the init-agent will create the CRD and then wait until its `Established` condition
+is `True` before considering this source complete. CRDs are just a nice example of a Kube-native
+resource that on its own becomes ready.
+
+The agent will keep retrying indefinitely. If a condition is never set, the workspace will remain
+in the initializing state. Use kcp's workspace lifecycle management to handle stuck workspaces if
+necessary.
+
+The annotation works with **any Kubernetes resource** that follows the standard conditions pattern
+in its status. Common examples include:
+
+| Resource | Typical Condition |
+| -------- | ----------------- |
+| `CustomResourceDefinition` | `Established` |
+| `Deployment` | `Available` |
+| `APIBinding` (kcp) | `Ready` |

internal/manifest/applier.go

@@ -21,7 +21,10 @@ import (
 	"errors"
 	"strings"
 
+	"go.uber.org/zap"
+
 	"github.com/kcp-dev/init-agent/internal/log"
+	"github.com/kcp-dev/init-agent/sdk/types"
 
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/meta"
@@ -53,18 +56,38 @@ func (a *applier) Apply(ctx context.Context, client ctrlruntimeclient.Client, ob
 		}
 	}
 
-	return false, nil
-}
+	// After creating objects, check readiness of annotated ones
+	for _, object := range objs {
+		conditionType := object.GetAnnotations()[types.WaitForReadyAnnotation]
+		if conditionType == "" {
+			continue
+		}
 
-func (a *applier) applyObject(ctx context.Context, client ctrlruntimeclient.Client, obj *unstructured.Unstructured) error {
-	gvk := obj.GroupVersionKind()
+		// Fetch current state
+		current := &unstructured.Unstructured{}
+		current.SetGroupVersionKind(object.GroupVersionKind())
 
-	key := ctrlruntimeclient.ObjectKeyFromObject(obj).String()
-	// make key look prettier for cluster-scoped objects
-	key = strings.TrimLeft(key, "/")
+		if err := client.Get(ctx, ctrlruntimeclient.ObjectKeyFromObject(object), current); err != nil {
+			if apierrors.IsNotFound(err) {
+				requeue = true
+				continue
+			}
+			return false, err
+		}
+
+		if !HasCondition(current, conditionType) {
+			logger := a.objectLogger(ctx, object)
+			logger.Debugw("Waiting for condition", "condition", conditionType)
+			requeue = true
+		}
+	}
 
-	logger := log.FromContext(ctx)
-	logger.Debugw("Applying object", "obj-key", key, "obj-gvk", gvk)
+	return requeue, nil
+}
+
+func (a *applier) applyObject(ctx context.Context, client ctrlruntimeclient.Client, obj *unstructured.Unstructured) error {
+	logger := a.objectLogger(ctx, obj)
+	logger.Debugw("Applying object")
 
 	if err := client.Create(ctx, obj); err != nil {
 		if !apierrors.IsAlreadyExists(err) {
@@ -74,3 +97,13 @@ func (a *applier) applyObject(ctx context.Context, client ctrlruntimeclient.Clie
 
 	return nil
 }
+
+func (a *applier) objectLogger(ctx context.Context, obj *unstructured.Unstructured) *zap.SugaredLogger {
+	gvk := obj.GroupVersionKind()
+
+	key := ctrlruntimeclient.ObjectKeyFromObject(obj).String()
+	// make key look prettier for cluster-scoped objects
+	key = strings.TrimLeft(key, "/")
+
+	return log.FromContext(ctx).With("obj-key", key, "obj-gvk", gvk)
+}

internal/manifest/readiness.go

@@ -0,0 +1,45 @@
+/*
+Copyright 2026 The kcp Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package manifest
+
+import (
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+)
+
+// HasCondition checks if an unstructured object has the specified condition
+// type with status "True".
+func HasCondition(obj *unstructured.Unstructured, conditionType string) bool {
+	conditions, found, err := unstructured.NestedSlice(obj.Object, "status", "conditions")
+	if err != nil || !found {
+		return false
+	}
+
+	for _, c := range conditions {
+		condition, ok := c.(map[string]any)
+		if !ok {
+			continue
+		}
+
+		cType, _, _ := unstructured.NestedString(condition, "type")
+		cStatus, _, _ := unstructured.NestedString(condition, "status")
+		if cType == conditionType && cStatus == "True" {
+			return true
+		}
+	}
+
+	return false
+}

internal/manifest/readiness_test.go

@@ -0,0 +1,151 @@
+/*
+Copyright 2026 The kcp Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package manifest
+
+import (
+	"testing"
+
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+)
+
+func TestHasCondition(t *testing.T) {
+	testcases := []struct {
+		name          string
+		obj           *unstructured.Unstructured
+		conditionType string
+		expected      bool
+	}{
+		{
+			name:          "no status",
+			obj:           newUnstructured("v1", "ConfigMap", "test"),
+			conditionType: "Ready",
+			expected:      false,
+		},
+		{
+			name:          "no conditions",
+			obj:           newUnstructuredWithStatus("v1", "ConfigMap", "test", map[string]any{}),
+			conditionType: "Ready",
+			expected:      false,
+		},
+		{
+			name:          "empty conditions",
+			obj:           newUnstructuredWithConditions("v1", "ConfigMap", "test", []any{}),
+			conditionType: "Ready",
+			expected:      false,
+		},
+		{
+			name: "condition type not found",
+			obj: newUnstructuredWithConditions("v1", "ConfigMap", "test", []any{
+				map[string]any{"type": "Available", "status": "True"},
+			}),
+			conditionType: "Ready",
+			expected:      false,
+		},
+		{
+			name: "condition found but status is False",
+			obj: newUnstructuredWithConditions("v1", "ConfigMap", "test", []any{
+				map[string]any{"type": "Ready", "status": "False"},
+			}),
+			conditionType: "Ready",
+			expected:      false,
+		},
+		{
+			name: "condition found but status is Unknown",
+			obj: newUnstructuredWithConditions("v1", "ConfigMap", "test", []any{
+				map[string]any{"type": "Ready", "status": "Unknown"},
+			}),
+			conditionType: "Ready",
+			expected:      false,
+		},
+		{
+			name: "condition found with status True",
+			obj: newUnstructuredWithConditions("v1", "ConfigMap", "test", []any{
+				map[string]any{"type": "Ready", "status": "True"},
+			}),
+			conditionType: "Ready",
+			expected:      true,
+		},
+		{
+			name: "multiple conditions - target is True",
+			obj: newUnstructuredWithConditions("v1", "ConfigMap", "test", []any{
+				map[string]any{"type": "Available", "status": "True"},
+				map[string]any{"type": "Ready", "status": "True"},
+				map[string]any{"type": "Progressing", "status": "False"},
+			}),
+			conditionType: "Ready",
+			expected:      true,
+		},
+		{
+			name: "multiple conditions - target is False",
+			obj: newUnstructuredWithConditions("v1", "ConfigMap", "test", []any{
+				map[string]any{"type": "Available", "status": "True"},
+				map[string]any{"type": "Ready", "status": "False"},
+				map[string]any{"type": "Progressing", "status": "True"},
+			}),
+			conditionType: "Ready",
+			expected:      false,
+		},
+		{
+			name: "CRD Established condition True",
+			obj: newUnstructuredWithConditions("apiextensions.k8s.io/v1", "CustomResourceDefinition", "test", []any{
+				map[string]any{"type": "NamesAccepted", "status": "True"},
+				map[string]any{"type": "Established", "status": "True"},
+			}),
+			conditionType: "Established",
+			expected:      true,
+		},
+		{
+			name: "CRD Established condition False",
+			obj: newUnstructuredWithConditions("apiextensions.k8s.io/v1", "CustomResourceDefinition", "test", []any{
+				map[string]any{"type": "NamesAccepted", "status": "True"},
+				map[string]any{"type": "Established", "status": "False"},
+			}),
+			conditionType: "Established",
+			expected:      false,
+		},
+		{
+			name: "malformed condition entry (not a map)",
+			obj: newUnstructuredWithConditions("v1", "ConfigMap", "test", []any{
+				"not a map",
+				map[string]any{"type": "Ready", "status": "True"},
+			}),
+			conditionType: "Ready",
+			expected:      true,
+		},
+	}
+
+	for _, tt := range testcases {
+		t.Run(tt.name, func(t *testing.T) {
+			result := HasCondition(tt.obj, tt.conditionType)
+			if result != tt.expected {
+				t.Fatalf("Expected %v.", tt.expected)
+			}
+		})
+	}
+}
+
+func newUnstructuredWithStatus(apiVersion, kind, name string, status map[string]any) *unstructured.Unstructured {
+	obj := newUnstructured(apiVersion, kind, name)
+	obj.Object["status"] = status
+	return obj
+}
+
+func newUnstructuredWithConditions(apiVersion, kind, name string, conditions []any) *unstructured.Unstructured {
+	return newUnstructuredWithStatus(apiVersion, kind, name, map[string]any{
+		"conditions": conditions,
+	})
+}