Merge pull request #1 from salaboy/serving-controller

Serving controller

Makefile

@@ -0,0 +1,37 @@
+.EXPORT_ALL_VARIABLES:
+SYSTEM_NAMESPACE ?= default
+METRICS_DOMAIN ?= example.com
+CLUSTER_NAME ?= knative-test
+EVENTSINK ?= http://localhost:10000
+
+install-knative:
+	kubectl apply -f https://github.com/knative/serving/releases/download/knative-v1.1.0/serving-crds.yaml
+	kubectl apply -f https://github.com/knative/serving/releases/download/knative-v1.1.0/serving-core.yaml
+	# install networking layer | kourier
+	kubectl apply -f https://github.com/knative/net-kourier/releases/download/knative-v1.1.0/kourier.yaml
+	kubectl patch configmap/config-network \
+		  --namespace knative-serving \
+		    --type merge \
+			  --patch '{"data":{"ingress-class":"kourier.ingress.networking.knative.dev"}}'
+
+
+install-crds:
+	for crd in config/crds; \
+	do \
+		kubectl apply -f "$$crd"; \
+	done
+
+run-controllers:
+	go run cmd/controller/main.go
+
+run-webhooks:
+	go run cmd/webhook/main.go
+
+run-schema:
+	go run cmd/schema/main.go dump SimpleDeployment
+
+cluster:
+	kind create cluster --name ${CLUSTER_NAME} --config kind-config.yaml
+
+delete-cluster:
+	kind delete cluster --name ${CLUSTER_NAME}

README.md

@@ -3,12 +3,85 @@
 [![GoDoc](https://godoc.org/knative.dev/sample-controller?status.svg)](https://godoc.org/knative.dev/sample-controller)
 [![Go Report Card](https://goreportcard.com/badge/knative/sample-controller)](https://goreportcard.com/report/knative/sample-controller)
 
-Knative `sample-controller` defines a few simple resources that are validated by
-webhook and managed by a controller to demonstrate the canonical style in which
-Knative writes controllers.
+Knative `servinng events controller` defines a controller for `knative serving` resource and listens for Knative Service events and generates corresponding `CloudEvents` taking the [tektoncd controller](https://github.com/tektoncd/experimental/tree/main/cloudevents) as a reference implementation.
 
-To learn more about Knative, please visit our
-[Knative docs](https://github.com/knative/docs) repository.
+### Controller architecture
+
+The following roughly defines the controller components:
+1. We register 2 Informers:
+    * [ServingV1/Service](knative.dev/serving/pkg/client/injection/informers/serving/v1/service)
+    * [ServiceV1/Revision](knative.dev/serving/pkg/client/injection/informers/serving/v1/revision)
+2. A `ServingV1/Service` reconciler
+3. Embed the [CloudEvents](github.com/cloudevents/sdk-go/v2) SDK client.
+4. We also register a CloudEvents 'receiver' which listens at port `8080`.
+
+The following sequence diagram shows the interaction between the components 
+
+![sequence](sequence_diagram.png)
+
+### Testing and running the controller
+1. Setup a test cluster using KIND with `make cluster`
+2. Install Knative with `make install-knative`
+3. Install CRDs with `make install-crds`
+4. Run the controller with `make run-controllers`
+
+#### Scenario 1 - Serving object to CloudEvent
+Now create a dummy Knative service 
+```
+echo "apiVersion: serving.knative.dev/v1
+kind: Service
+metadata:
+  name: hello
+spec:
+  template:
+    spec:
+      containers:
+      - image: gcr.io/google-samples/hello-app:1.0
+" | kubectl apply -f -
+```
+
+We will see the corresponding events received by the controller and subsequently the emitted `cloudevent` received:
+```
+Context Attributes,
+  specversion: 1.0
+  type: cd.service.deployed.v1      # event of type deployed
+  source: default/hello
+  id: 1fc4b160-e859-4177-8847-b85c19fdbc18
+  time: 2022-01-20T16:56:39.010077Z
+```
+
+On updating the previously created `ksvc` object, we should see a corresponding event of type `upgraded`
+```diff
+- - image: gcr.io/google-samples/hello-app:1.0
++ - image: gcr.io/google-samples/hello-app:2.0
+```
+This generates the upgraded event and should be reflected in the event as well:
+```
+Context Attributes,
+  specversion: 1.0
+  type: cd.service.upgraded.v1      # event of type upgraded
+  source: default/hello
+  id: 23225ed1-3dcc-4772-a60d-72ab57bb1ba3
+  time: 2022-01-20T17:16:00.253051Z
+
+```
+
+#### Scenario 2 - CloudEvent triggering a Knative service creation
+1. Clearing the previous `ksvc` object
+```
+kubectl delete ksvc hello
+```
+2. Trigger a cloud event of type `created` (`cd.service.created.v1`) with the following command:
+```
+go run cmd/cloudevent/produce.go
+```
+This should create a `ksvc` object in the cluster
+> note that the event used here (`cd.service.created.v1`) is not yet defined by the CloudEvents sdk and is just hardcoded for demo purposes.
+
+Check for the created Knative service by running:
+```
+kubectl get ksvc 
+```
 
 If you are interested in contributing, see [CONTRIBUTING.md](./CONTRIBUTING.md)
 and [DEVELOPMENT.md](./DEVELOPMENT.md).

cmd/cloudevent/produce.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"context"
+	"log"
+
+	cloudevents "github.com/cloudevents/sdk-go/v2"
+	"knative.dev/sample-controller/pkg/server/models"
+)
+
+func main() {
+	c, err := cloudevents.NewClientHTTP()
+	if err != nil {
+		log.Fatalf("failed to create client, %v", err)
+	}
+
+	// Create an Event.
+	event := cloudevents.NewEvent()
+	event.SetSource("example/uri")
+	event.SetType(models.CreateKService.String())
+	event.SetData(cloudevents.ApplicationJSON, map[string]string{
+		"name":      "hello",
+		"namespace": "default",
+		"image":     "gcr.io/google-samples/hello-app:1.0",
+	})
+
+	// Set a target.
+	ctx := cloudevents.ContextWithTarget(context.Background(), "http://localhost:10000/")
+
+	// Send that Event.
+	if result := c.Send(ctx, event); cloudevents.IsUndelivered(result) {
+		log.Fatalf("failed to send, %v", result)
+	}
+}

cmd/controller/main.go

@@ -17,17 +17,20 @@ limitations under the License.
 package main
 
 import (
+
 	// The set of controllers this controller process runs.
-	"knative.dev/sample-controller/pkg/reconciler/addressableservice"
-	"knative.dev/sample-controller/pkg/reconciler/simpledeployment"
+
+	"knative.dev/sample-controller/pkg/reconciler/serving"
 
 	// This defines the shared main for injected controllers.
 	"knative.dev/pkg/injection/sharedmain"
 )
 
 func main() {
 	sharedmain.Main("controller",
-		addressableservice.NewController,
-		simpledeployment.NewController,
+		// addressableservice.NewController,
+		// simpledeployment.NewController,
+		serving.NewController,
 	)
+
 }

go.mod

@@ -3,13 +3,16 @@ module knative.dev/sample-controller
 go 1.15
 
 require (
-	go.uber.org/zap v1.19.1
+	github.com/cdfoundation/sig-events/cde/sdk/go v0.0.0-20211122192319-2ad36f58fc2c
+	github.com/cloudevents/sdk-go/v2 v2.8.0
+	github.com/kelseyhightower/envconfig v1.4.0
+	github.com/satori/go.uuid v1.2.0
 	k8s.io/api v0.22.5
 	k8s.io/apimachinery v0.22.5
 	k8s.io/client-go v0.22.5
 	k8s.io/code-generator v0.22.5
 	k8s.io/kube-openapi v0.0.0-20211109043538-20434351676c
 	knative.dev/hack v0.0.0-20211222071919-abd085fc43de
-	knative.dev/hack/schema v0.0.0-20211222071919-abd085fc43de
 	knative.dev/pkg v0.0.0-20220104185830-52e42b760b54
+	knative.dev/serving v0.28.0
 )