Pull example code into eventing-contrib (#801) (#803)

(cherry picked from commit de462bc)

add appender to release, alphatebize files (#802)

(cherry picked from commit ffe7343)

cmd/appender/main.go

@@ -0,0 +1,98 @@
+/*
+Copyright 2019 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
+
+	https://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 (
+	"context"
+	"log"
+	"os"
+
+	cloudevents "github.com/cloudevents/sdk-go"
+	"github.com/kelseyhightower/envconfig"
+)
+
+/*
+Small function that demonstrates two concepts:
+
+1. Deserializing / Serializing data
+2. Using direct reply to modify incoming events (decorating in this example)
+
+Incoming data is assumbed to be CloudEventBaseData with two fields
+ Sequence int
+ Message string
+
+This function appends env[MESSAGE] to the Message portion of the data.
+It is used by the samples in the Knative sequence section:
+https://knative.dev/docs/eventing/sequence/
+*/
+
+type envConfig struct {
+	Msg string `envconfig:"MESSAGE" default:"boring default msg, change me with env[MESSAGE]"`
+}
+
+var (
+	env envConfig
+)
+
+// Define a small struct representing the data for our expected data.
+type cloudEventBaseData struct {
+	Sequence int    `json:"id"`
+	Message  string `json:"message"`
+}
+
+func gotEvent(event cloudevents.Event, resp *cloudevents.EventResponse) error {
+	ctx := event.Context.AsV1()
+
+	data := &cloudEventBaseData{}
+	if err := event.DataAs(data); err != nil {
+		log.Printf("Got Data Error: %s\n", err.Error())
+		return err
+	}
+
+	log.Println("Received a new event: ")
+	log.Printf("[%s] %s %s: %+v", ctx.Time.String(), ctx.GetSource(), ctx.GetType(), data)
+
+	// append eventMsgAppender to message of the data
+	data.Message = data.Message + env.Msg
+	r := cloudevents.Event{
+		Context: ctx,
+		Data:    data,
+	}
+
+	r.SetDataContentType(cloudevents.ApplicationJSON)
+
+	log.Println("Transform the event to: ")
+	log.Printf("[%s] %s %s: %+v", ctx.Time.String(), ctx.GetSource(), ctx.GetType(), data)
+
+	resp.RespondWith(200, &r)
+	return nil
+}
+
+func main() {
+	if err := envconfig.Process("", &env); err != nil {
+		log.Printf("[ERROR] Failed to process env var: %s", err)
+		os.Exit(1)
+	}
+
+	c, err := cloudevents.NewDefaultClient()
+	if err != nil {
+		log.Fatalf("failed to create client, %v", err)
+	}
+
+	log.Printf("listening on 8080, appending %q to events", env.Msg)
+	log.Fatalf("failed to start receiver: %s", c.StartReceiver(context.Background(), gotEvent))
+}

config/tools/appender/appender.yaml

@@ -0,0 +1,30 @@
+# Copyright 2019 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.
+
+# This is a very simple Knative Service that writes the incoming CloudEvent to its log.
+apiVersion: serving.knative.dev/v1
+kind: Service
+metadata:
+  name: first
+  namespace: seqtest4
+  labels:
+    contrib.eventing.knative.dev/release: devel
+spec:
+  template:
+    spec:
+      containers:
+      - env:
+        - name: MESSAGE
+          value: "...your message goes here..."
+        image: knative.dev/eventing-contrib/cmd/appender

hack/release.sh

@@ -22,14 +22,15 @@ source $(dirname $0)/../vendor/knative.dev/test-infra/scripts/release.sh
 # Yaml files to generate, and the source config dir for them.
 declare -A COMPONENTS
 COMPONENTS=(
-  ["github.yaml"]="github/config"
-  ["event-display.yaml"]="config/tools/event-display"
+  ["appender.yaml"]="config/tools/appender"
+  ["awssqs.yaml"]="awssqs/config"
   ["camel.yaml"]="camel/source/config"
+  ["couchdb.yaml"]="couchdb/source/config"
+  ["event-display.yaml"]="config/tools/event-display"
+  ["github.yaml"]="github/config"
   ["kafka-source.yaml"]="kafka/source/config"
   ["kafka-channel.yaml"]="kafka/channel/config"
   ["natss-channel.yaml"]="natss/config"
-  ["awssqs.yaml"]="awssqs/config"
-  ["couchdb.yaml"]="couchdb/source/config"
   ["prometheus-source.yaml"]="prometheus/config"
 )
 readonly COMPONENTS
@@ -47,7 +48,7 @@ function build_release() {
   local all_yamls=()
   for yaml in "${!COMPONENTS[@]}"; do
     local config="${COMPONENTS[${yaml}]}"
-    echo "Building Knative Eventing Sources - ${config}"
+    echo "Building Knative Eventing Contrib - ${config}"
     ko resolve ${KO_FLAGS} -f ${config}/ | "${LABEL_YAML_CMD[@]}" > ${yaml}
     all_yamls+=(${yaml})
   done