Create the in-memory-channel ClusterProvisioner

cmd/fanoutsidecar/main.go

@@ -21,27 +21,27 @@ package main
 
 import (
 	"context"
-	"errors"
 	"flag"
 	"fmt"
+	"log"
+	"net/http"
+	"strings"
+	"time"
+
 	"github.com/knative/eventing/pkg/sidecar/configmap/filesystem"
 	"github.com/knative/eventing/pkg/sidecar/configmap/watcher"
 	"github.com/knative/eventing/pkg/sidecar/swappable"
 	"github.com/knative/eventing/pkg/system"
 	"go.uber.org/zap"
 	"golang.org/x/sync/errgroup"
 	"k8s.io/client-go/kubernetes"
-	"log"
-	"net/http"
 	"sigs.k8s.io/controller-runtime/pkg/client/config"
 	"sigs.k8s.io/controller-runtime/pkg/manager"
 	"sigs.k8s.io/controller-runtime/pkg/runtime/signals"
-	"strings"
-	"time"
 )
 
 const (
-	defaultConfigMapName = "in-memory-bus-config"
+	defaultConfigMapName = "in-memory-channel-dispatcher-config-map"
 
 	// The following are the only valid values of the config_map_noticer flag.
 	cmnfVolume  = "volume"
@@ -60,12 +60,12 @@ var (
 
 func init() {
 	flag.IntVar(&port, "sidecar_port", -1, "The port to run the sidecar on.")
-	flag.StringVar(&configMapNoticer, "config_map_noticer", "", fmt.Sprintf("The system to notice changes to the ConfigMap. Valid values are: %s", configMapNoticerFlags()))
+	flag.StringVar(&configMapNoticer, "config_map_noticer", "", fmt.Sprintf("The system to notice changes to the ConfigMap. Valid values are: %s", configMapNoticerValues()))
 	flag.StringVar(&configMapNamespace, "config_map_namespace", system.Namespace, "The namespace of the ConfigMap that is watched for configuration.")
 	flag.StringVar(&configMapName, "config_map_name", defaultConfigMapName, "The name of the ConfigMap that is watched for configuration.")
 }
 
-func configMapNoticerFlags() string {
+func configMapNoticerValues() string {
 	return strings.Join([]string{cmnfVolume, cmnfWatcher}, ", ")
 }
 
@@ -132,7 +132,7 @@ func setupConfigMapNoticer(logger *zap.Logger, configUpdated swappable.UpdateCon
 	case cmnfWatcher:
 		err = setupConfigMapWatcher(logger, mgr, configUpdated)
 	default:
-		err = errors.New("need to provide the --config_map_noticer flag")
+		err = fmt.Errorf("need to provide the --config_map_noticer flag (valid values are %s)", configMapNoticerValues())
 	}
 	if err != nil {
 		return nil, err

config/provisioners/in-memory-channel/README.md

@@ -0,0 +1,63 @@
+# In-Memory Channels
+
+In-memory channels are a best effort Channel. They should **NOT** be used in Production. They are 
+useful for development.
+
+They differ from most Channels in that they have:
+* No persistence.
+    - If a Pod goes down, messages go with it.
+* No ordering guarantee.
+    - There is nothing enforcing an ordering, so two messages that arrive at the same time may
+      go downstream in any order.
+    - Different downstream subscribers may see different orders.
+* No redelivery attempts.
+    - If downstream rejects a request, a log message is written, but that request is never sent 
+      again.
+
+
+### Deployment steps:
+
+1. Setup [Knative Eventing](../../../DEVELOPMENT.md).
+1. Apply the 'in-memory-channel' ClusterProvisioner, Controller, and Dispatcher.
+     ```shell
+     ko apply -f config/providers/in-memory-channel/in-memory-channel.yaml
+     ````
+1. Create Channels that reference the 'in-memory-channel'.
+
+    ```yaml
+    apiVersion: eventing.knative.dev/v1alpha1
+    kind: Channel
+    metadata:
+      name: foo
+    spec:
+      provisioner:
+        ref:
+          apiVersion: eventing.knative.dev/v1alpha1
+          kind: ClusterProvisioner
+          name: in-memory-channel
+    ```
+
+### Components
+
+The major components are:
+* ClusterProvisioner Controller
+* Channel Controller
+* Channel Dispatcher
+* Channel Dispatcher Config Map.
+
+The ClusterProvisioner Controller and the Channel Controller are colocated in one Pod.
+```shell
+kubectl get deployment -n knative-eventing in-memory-channel-controller
+```
+
+The Channel Dispatcher receives and distributes all events. There is a single Dispatcher for all
+in-memory Channels.
+```shell
+kubectl get deployment -n knative-eventing in-memory-channel-dispatcher
+```
+
+The Channel Dispatcher Config Map is used to send information about Channels and Subscriptions from
+the Channel Controller to the Channel Dispatcher.
+```shell
+kubectl get configmap -n knative-eventing in-memory-channel-dispatcher-config-map
+```

config/provisioners/in-memory-channel/in-memory-channel.yaml

@@ -0,0 +1,183 @@
+# Copyright 2018 The Knative 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.
+
+apiVersion: eventing.knative.dev/v1alpha1
+kind: ClusterProvisioner
+metadata:
+  name: in-memory-channel
+spec:
+  reconciles:
+    group: eventing.knative.dev/v1alpha1
+    kind: Channel
+
+---
+
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: in-memory-channel-controller
+  namespace: knative-eventing
+
+---
+
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: in-memory-channel-controller
+rules:
+  - apiGroups:
+      - eventing.knative.dev
+    resources:
+      - channels
+      - clusterprovisioners
+    verbs:
+      - get
+      - list
+      - watch
+      - update
+  - apiGroups:
+      - "" # Core API group.
+    resources:
+      - configmaps
+      - services
+    verbs:
+      - get
+      - list
+      - watch
+      - create
+  - apiGroups:
+      - "" # Core API Group.
+    resources:
+      - configmaps
+    resourceNames:
+      - in-memory-channel-dispatcher-config-map
+    verbs:
+      - update
+  - apiGroups:
+      - networking.istio.io
+    resources:
+      - virtualservices
+    verbs:
+      - get
+      - list
+      - watch
+      - create
+
+---
+
+apiVersion: rbac.authorization.k8s.io/v1beta1
+kind: ClusterRoleBinding
+metadata:
+  name: in-memory-channel-controller
+  namespace: knative-eventing
+subjects:
+  - kind: ServiceAccount
+    name: in-memory-channel-controller
+    namespace: knative-eventing
+roleRef:
+  kind: ClusterRole
+  name: in-memory-channel-controller
+  apiGroup: rbac.authorization.k8s.io
+
+---
+
+apiVersion: apps/v1beta1
+kind: Deployment
+metadata:
+  name: in-memory-channel-controller
+  namespace: knative-eventing
+spec:
+  replicas: 1
+  selector:
+    matchLabels: &labels
+      clusterProvisioner: in-memory-channel
+      role: controller
+  template:
+    metadata:
+      labels: *labels
+    spec:
+      serviceAccountName: in-memory-channel-controller
+      containers:
+        - name: controller
+          image: github.com/knative/eventing/pkg/controller/eventing/inmemory/controller
+
+---
+
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: in-memory-channel-dispatcher
+  namespace: knative-eventing
+
+---
+
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: in-memory-channel-dispatcher
+  namespace: knative-eventing
+rules:
+  - apiGroups:
+      - "" # Core API group.
+    resources:
+      - configmaps
+    verbs:
+      - get
+      - list
+      - watch
+
+---
+
+apiVersion: rbac.authorization.k8s.io/v1beta1
+kind: ClusterRoleBinding
+metadata:
+  name: in-memory-channel-dispatcher
+  namespace: knative-eventing
+subjects:
+  - kind: ServiceAccount
+    name: in-memory-channel-dispatcher
+    namespace: knative-eventing
+roleRef:
+  kind: ClusterRole
+  name: in-memory-channel-dispatcher
+  apiGroup: rbac.authorization.k8s.io
+
+---
+
+apiVersion: apps/v1beta1
+kind: Deployment
+metadata:
+  name: in-memory-channel-dispatcher
+  namespace: knative-eventing
+spec:
+  replicas: 1
+  selector:
+    matchLabels: &labels
+      clusterProvisioner: in-memory-channel
+      role: dispatcher
+  template:
+    metadata:
+      annotations:
+        sidecar.istio.io/inject: "true"
+      labels: *labels
+    spec:
+      serviceAccountName: in-memory-channel-dispatcher
+      containers:
+        - name: dispatcher
+          image: github.com/knative/eventing/cmd/fanoutsidecar
+          args:
+            - --sidecar_port=8080
+            - --config_map_noticer=watcher
+            - --config_map_namespace=knative-eventing
+            - --config_map_name=in-memory-channel-dispatcher-config-map