Further consolidate the libraries

api/handler/cloudevents/cloudevents.go

@@ -0,0 +1,94 @@
+// Package cloudevents provides a cloudevents handler publishing the event using the go-micro/client
+package cloudevents
+
+import (
+	"net/http"
+	"path"
+	"regexp"
+	"strings"
+
+	"github.com/micro/go-micro/api/handler"
+	"github.com/micro/go-micro/util/ctx"
+)
+
+type event struct {
+	options handler.Options
+}
+
+var (
+	Handler   = "cloudevents"
+	versionRe = regexp.MustCompilePOSIX("^v[0-9]+$")
+)
+
+func eventName(parts []string) string {
+	return strings.Join(parts, ".")
+}
+
+func evRoute(ns, p string) (string, string) {
+	p = path.Clean(p)
+	p = strings.TrimPrefix(p, "/")
+
+	if len(p) == 0 {
+		return ns, "event"
+	}
+
+	parts := strings.Split(p, "/")
+
+	// no path
+	if len(parts) == 0 {
+		// topic: namespace
+		// action: event
+		return strings.Trim(ns, "."), "event"
+	}
+
+	// Treat /v[0-9]+ as versioning
+	// /v1/foo/bar => topic: v1.foo action: bar
+	if len(parts) >= 2 && versionRe.Match([]byte(parts[0])) {
+		topic := ns + "." + strings.Join(parts[:2], ".")
+		action := eventName(parts[1:])
+		return topic, action
+	}
+
+	// /foo => topic: ns.foo action: foo
+	// /foo/bar => topic: ns.foo action: bar
+	topic := ns + "." + strings.Join(parts[:1], ".")
+	action := eventName(parts[1:])
+
+	return topic, action
+}
+
+func (e *event) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	// request to topic:event
+	// create event
+	// publish to topic
+	topic, _ := evRoute(e.options.Namespace, r.URL.Path)
+
+	// create event
+	ev, err := FromRequest(r)
+	if err != nil {
+		http.Error(w, err.Error(), 500)
+		return
+	}
+
+	// get client
+	c := e.options.Service.Client()
+
+	// create publication
+	p := c.NewMessage(topic, ev)
+
+	// publish event
+	if err := c.Publish(ctx.FromRequest(r), p); err != nil {
+		http.Error(w, err.Error(), 500)
+		return
+	}
+}
+
+func (e *event) String() string {
+	return "cloudevents"
+}
+
+func NewHandler(opts ...handler.Option) handler.Handler {
+	return &event{
+		options: handler.NewOptions(opts...),
+	}
+}