Add HTTP trigger API and client

This implemenents create/read/update/delete/list for http triggers.
This isn't quite the final implementation: you can't look up old
versions by UUID since it only stores the latest update.  I'll get to
that later.

controller/httpTriggerApi.go

@@ -0,0 +1,151 @@
+/*
+Copyright 2016 The Fission 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 controller
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/gorilla/mux"
+
+	"github.com/platform9/fission"
+)
+
+func (api *API) HTTPTriggerApiList(w http.ResponseWriter, r *http.Request) {
+	triggers, err := api.HTTPTriggerStore.List()
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	resp, err := json.Marshal(triggers)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	api.respondWithSuccess(w, resp)
+}
+
+func (api *API) HTTPTriggerApiCreate(w http.ResponseWriter, r *http.Request) {
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		api.respondWithError(w, err)
+	}
+
+	var t fission.HTTPTrigger
+	err = json.Unmarshal(body, &t)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	uid, err := api.HTTPTriggerStore.Create(&t)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	m := &fission.Metadata{Name: t.Name, Uid: uid}
+	resp, err := json.Marshal(m)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	api.respondWithSuccess(w, resp)
+}
+
+func (api *API) HTTPTriggerApiGet(w http.ResponseWriter, r *http.Request) {
+	var m fission.Metadata
+
+	vars := mux.Vars(r)
+	m.Name = vars["httpTrigger"]
+	m.Uid = r.FormValue("uid") // empty if uid is absent
+
+	t, err := api.HTTPTriggerStore.Get(&m)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	resp, err := json.Marshal(t)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	api.respondWithSuccess(w, resp)
+}
+
+func (api *API) HTTPTriggerApiUpdate(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	name := vars["httpTrigger"]
+
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		api.respondWithError(w, err)
+	}
+
+	var t fission.HTTPTrigger
+	err = json.Unmarshal(body, &t)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	if name != t.Metadata.Name {
+		err = fission.MakeError(fission.ErrorInvalidArgument, "HTTPTrigger name doesn't match URL")
+		api.respondWithError(w, err)
+		return
+	}
+
+	uid, err := api.HTTPTriggerStore.Update(&t)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	m := &fission.Metadata{Name: t.Name, Uid: uid}
+	resp, err := json.Marshal(m)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+	api.respondWithSuccess(w, resp)
+}
+
+func (api *API) HTTPTriggerApiDelete(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	var m fission.Metadata
+	m.Name = vars["httpTrigger"]
+
+	m.Uid = r.FormValue("uid") // empty if uid is absent
+	if len(m.Uid) == 0 {
+		log.WithFields(log.Fields{"httpTrigger": m.Name}).Info("Deleting all versions")
+	}
+
+	err := api.HTTPTriggerStore.Delete(m)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	api.respondWithSuccess(w, []byte(""))
+}