Add utility to send events

cmd/sendevent/main.go

@@ -0,0 +1,104 @@
+/*
+Copyright 2018 Google LLC
+
+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.
+*/
+
+// Implements a simple utility for sending a JSON-encoded sample event.
+// Not wired to bazel because this utility is meant to be run directly rather
+// than deployed to K8S
+package main
+
+import (
+	"crypto/rand"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/elafros/eventing/pkg/event"
+)
+
+var (
+	context event.Context
+	webhook string
+	data    string
+)
+
+func init() {
+	flag.StringVar(&context.EventID, "event-id", "", "Event ID to use. Defaults to a UUID")
+	flag.StringVar(&context.EventType, "event-type", "google.events.action.demo", "The Event Type to use.")
+	flag.StringVar(&context.Source, "source", "", "Source URI to use. Defaults to the current machine's hostname")
+	flag.StringVar(&data, "data", `{"hello": "world!"}`, "Event data")
+}
+
+func main() {
+	flag.Parse()
+
+	if len(flag.Args()) != 1 {
+		fmt.Println("Usage: sendevent [flags] <webhook>\nFor details about valid flags, run sendevent --help")
+		os.Exit(1)
+	}
+
+	webhook := flag.Arg(0)
+
+	var untyped map[string]interface{}
+	if err := json.Unmarshal([]byte(data), &untyped); err != nil {
+		fmt.Println("Currently sendevent only supports JSON event data")
+		os.Exit(1)
+	}
+
+	fillEventContext(&context)
+	req, err := event.NewRequest(webhook, untyped, context)
+	if err != nil {
+		fmt.Printf("Failed to create request: %s", err)
+		os.Exit(1)
+	}
+
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		fmt.Printf("Failed to send event to %s: %s\n", webhook, err)
+		os.Exit(1)
+	}
+	fmt.Printf("Got response from %s\n%s\n", webhook, res.Status)
+	if res.Header.Get("Content-Length") != "" {
+		bytes, _ := ioutil.ReadAll(res.Body)
+		fmt.Println(string(bytes))
+	}
+}
+
+func fillEventContext(ctx *event.Context) {
+	ctx.CloudEventsVersion = "0.1"
+	ctx.EventTime = time.Now().UTC()
+
+	if ctx.EventID == "" {
+		// A "UUID". Not technically spec complaint
+		b := make([]byte, 16)
+		if n, err := rand.Read(b); n != 16 || err != nil {
+			fmt.Println("Could not create event-id UUID")
+			os.Exit(1)
+		}
+		ctx.EventID = fmt.Sprintf("%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:])
+	}
+
+	if ctx.Source == "" {
+		var err error
+		ctx.Source, err = os.Hostname()
+		if err != nil {
+			ctx.Source = "localhost"
+		}
+	}
+}