Implemented Cron Job source

Used Deployment as receive adapter instead of CronJob becasue of
the batched job side car issue.

kubernetes/kubernetes#25908

If this issue is resolved in the future, we can switch to use CronJob.

cmd/cronjob_receive_adapter/main.go

@@ -0,0 +1,68 @@
+/*
+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.
+*/
+
+package main
+
+import (
+	"flag"
+	"log"
+	"os"
+
+	"github.com/knative/eventing-sources/pkg/adapter/cronjobevents"
+	"go.uber.org/zap"
+
+	"golang.org/x/net/context"
+)
+
+const (
+	// Environment variable container schedule.
+	envSchedue = "SCHEDULE"
+
+	// Environment variable containing data.
+	envData = "DATA"
+
+	// Sink for messages.
+	envSinkURI = "SINK_URI"
+)
+
+func getRequiredEnv(envKey string) string {
+	val, defined := os.LookupEnv(envKey)
+	if !defined {
+		log.Fatalf("required environment variable not defined '%s'", envKey)
+	}
+	return val
+}
+
+func main() {
+	flag.Parse()
+
+	ctx := context.Background()
+	logger, err := zap.NewProduction()
+	if err != nil {
+		log.Fatalf("Unable to create logger: %v", err)
+	}
+
+	adapter := &cronjobevents.Adapter{
+		Schedule: getRequiredEnv(envSchedue),
+		Data:     getRequiredEnv(envData),
+		SinkURI:  getRequiredEnv(envSinkURI),
+	}
+
+	logger.Info("Starting Receive Adapter. %v", zap.Reflect("adapter", adapter))
+	if err := adapter.Start(ctx); err != nil {
+		logger.Fatal("Failed to start adapter: ", zap.Error(err))
+	}
+}

config/crds/sources_v1alpha1_cronjobsource.yaml

@@ -0,0 +1,70 @@
+apiVersion: apiextensions.k8s.io/v1beta1
+kind: CustomResourceDefinition
+metadata:
+  creationTimestamp: null
+  labels:
+    controller-tools.k8s.io: "1.0"
+  name: cronjobsources.sources.eventing.knative.dev
+spec:
+  group: sources.eventing.knative.dev
+  names:
+    categories:
+    - all
+    - knative
+    - eventing
+    - sources
+    kind: CronJobSource
+    plural: cronjobsources
+  scope: Namespaced
+  validation:
+    openAPIV3Schema:
+      properties:
+        apiVersion:
+          type: string
+        kind:
+          type: string
+        metadata:
+          type: object
+        spec:
+          properties:
+            schedule:
+              type: string
+            data:
+              type: string
+            serviceAccountName:
+              type: string
+            sink:
+              type: object
+          type: object
+        status:
+          properties:
+            conditions:
+              items:
+                properties:
+                  lastTransitionTime:
+                    type: object
+                  message:
+                    type: string
+                  reason:
+                    type: string
+                  severity:
+                    type: string
+                  status:
+                    type: string
+                  type:
+                    type: string
+                required:
+                - type
+                - status
+                type: object
+              type: array
+            sinkUri:
+              type: string
+          type: object
+  version: v1alpha1
+status:
+  acceptedNames:
+    kind: ""
+    plural: ""
+  conditions: []
+  storedVersions: []

config/default.yaml

@@ -85,6 +85,77 @@ status:
 ---
 apiVersion: apiextensions.k8s.io/v1beta1
 kind: CustomResourceDefinition
+metadata:
+  creationTimestamp: null
+  labels:
+    controller-tools.k8s.io: "1.0"
+  name: cronjobsources.sources.eventing.knative.dev
+spec:
+  group: sources.eventing.knative.dev
+  names:
+    categories:
+    - all
+    - knative
+    - eventing
+    - sources
+    kind: CronJobSource
+    plural: cronjobsources
+  scope: Namespaced
+  validation:
+    openAPIV3Schema:
+      properties:
+        apiVersion:
+          type: string
+        kind:
+          type: string
+        metadata:
+          type: object
+        spec:
+          properties:
+            data:
+              type: string
+            schedule:
+              type: string
+            serviceAccountName:
+              type: string
+            sink:
+              type: object
+          type: object
+        status:
+          properties:
+            conditions:
+              items:
+                properties:
+                  lastTransitionTime:
+                    type: string
+                  message:
+                    type: string
+                  reason:
+                    type: string
+                  severity:
+                    type: string
+                  status:
+                    type: string
+                  type:
+                    type: string
+                required:
+                - type
+                - status
+                type: object
+              type: array
+            sinkUri:
+              type: string
+          type: object
+  version: v1alpha1
+status:
+  acceptedNames:
+    kind: ""
+    plural: ""
+  conditions: []
+  storedVersions: []
+---
+apiVersion: apiextensions.k8s.io/v1beta1
+kind: CustomResourceDefinition
 metadata:
   creationTimestamp: null
   labels:
@@ -414,6 +485,18 @@ rules:
   - update
   - patch
   - delete
+- apiGroups:
+  - sources.eventing.knative.dev
+  resources:
+  - cronjobsources
+  verbs:
+  - get
+  - list
+  - watch
+  - create
+  - update
+  - patch
+  - delete
 - apiGroups:
   - ""
   resources:
@@ -482,6 +565,8 @@ spec:
           value: github.com/knative/eventing-sources/cmd/kuberneteseventsource
         - name: GH_RA_IMAGE
           value: github.com/knative/eventing-sources/cmd/githubsource
+        - name: CRONJOB_RA_IMAGE
+          value: github.com/knative/eventing-sources/cmd/cronjob_receive_adapter
         image: github.com/knative/eventing-sources/cmd/manager
         name: manager
         resources:

config/default/cronjobsource_conditions_patch.yaml

@@ -0,0 +1,17 @@
+# this fixes the auto-detected object, we use a string in the stored object but
+# a wrapper object for time at runtime.
+apiVersion: apiextensions.k8s.io/v1beta1
+kind: CustomResourceDefinition
+metadata:
+  name: cronjobsources.sources.eventing.knative.dev
+spec:
+  validation:
+    openAPIV3Schema:
+      properties:
+        status:
+          properties:
+            conditions:
+              items:
+                properties:
+                  lastTransitionTime:
+                    type: string

config/default/kustomization.yaml

@@ -10,6 +10,7 @@ resources:
 - ../crds/sources_v1alpha1_containersource.yaml
 - ../crds/sources_v1alpha1_kuberneteseventsource.yaml
 - ../crds/sources_v1alpha1_githubsource.yaml
+- ../crds/sources_v1alpha1_cronjobsource.yaml
 - ../rbac/rbac_role.yaml
 - ../rbac/rbac_role_binding.yaml
 - ../manager/manager.yaml
@@ -19,3 +20,4 @@ patches:
 - containersource_conditions_patch.yaml
 - kuberneteseventsource_conditions_patch.yaml
 - githubsource_conditions_patch.yaml
+- cronjobsource_conditions_patch.yaml

config/default/manager_image_patch.yaml

@@ -13,3 +13,5 @@ spec:
           value: github.com/knative/eventing-sources/cmd/kuberneteseventsource
         - name: GH_RA_IMAGE
           value: github.com/knative/eventing-sources/cmd/githubsource
+        - name: CRONJOB_RA_IMAGE
+          value: github.com/knative/eventing-sources/cmd/cronjob_receive_adapter

config/rbac/rbac_role.yaml

@@ -132,6 +132,18 @@ rules:
   - update
   - patch
   - delete
+- apiGroups:
+  - sources.eventing.knative.dev
+  resources:
+  - cronjobsources
+  verbs:
+  - get
+  - list
+  - watch
+  - create
+  - update
+  - patch
+  - delete
 - apiGroups:
   - ""
   resources: