Add Time Trigger API and client (#153) (#161)

This change adds a timer trigger API, client, and implementation.  Users can trigger a function with a cron-compatible string. 

This change also moves the publisher interface and webhook-based publisher implementation out of kubewatcher and into a separate `publisher` package.

controller/timeTriggerApi.go

@@ -0,0 +1,181 @@
+/*
+Copyright 2017 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/robfig/cron"
+
+	"github.com/fission/fission"
+)
+
+func (api *API) TimeTriggerApiList(w http.ResponseWriter, r *http.Request) {
+	triggers, err := api.TimeTriggerStore.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) TimeTriggerApiCreate(w http.ResponseWriter, r *http.Request) {
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		api.respondWithError(w, err)
+	}
+
+	var t fission.TimeTrigger
+	err = json.Unmarshal(body, &t)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	triggers, err := api.TimeTriggerStore.List()
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+	for _, trigger := range triggers {
+		if trigger.Name == t.Name {
+			err = fission.MakeError(fission.ErrorNameExists,
+				"TimeTrigger with same name already exists")
+			api.respondWithError(w, err)
+			return
+		}
+	}
+
+	_, err = cron.Parse(t.Cron)
+	if err != nil {
+		err = fission.MakeError(fission.ErrorInvalidArgument, "TimeTrigger cron spec is not valid")
+		api.respondWithError(w, err)
+		return
+	}
+
+	uid, err := api.TimeTriggerStore.Create(&t)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	m := &fission.Metadata{Name: t.Metadata.Name, Uid: uid}
+	resp, err := json.Marshal(m)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	w.WriteHeader(http.StatusCreated)
+	api.respondWithSuccess(w, resp)
+}
+
+func (api *API) TimeTriggerApiGet(w http.ResponseWriter, r *http.Request) {
+	var m fission.Metadata
+
+	vars := mux.Vars(r)
+	m.Name = vars["timeTrigger"]
+	m.Uid = r.FormValue("uid") // empty if uid is absent
+
+	t, err := api.TimeTriggerStore.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) TimeTriggerApiUpdate(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	name := vars["timeTrigger"]
+
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		api.respondWithError(w, err)
+	}
+
+	var t fission.TimeTrigger
+	err = json.Unmarshal(body, &t)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	if name != t.Metadata.Name {
+		err = fission.MakeError(fission.ErrorInvalidArgument, "TimeTrigger name doesn't match URL")
+		api.respondWithError(w, err)
+		return
+	}
+
+	_, err = cron.Parse(t.Cron)
+	if err != nil {
+		err = fission.MakeError(fission.ErrorInvalidArgument, "TimeTrigger cron spec is not valid")
+		api.respondWithError(w, err)
+		return
+	}
+
+	uid, err := api.TimeTriggerStore.Update(&t)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	m := &fission.Metadata{Name: t.Metadata.Name, Uid: uid}
+	resp, err := json.Marshal(m)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+	api.respondWithSuccess(w, resp)
+}
+
+func (api *API) TimeTriggerApiDelete(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	var m fission.Metadata
+	m.Name = vars["timeTrigger"]
+
+	m.Uid = r.FormValue("uid") // empty if uid is absent
+	if len(m.Uid) == 0 {
+		log.WithFields(log.Fields{"timeTrigger": m.Name}).Info("Deleting all versions")
+	}
+
+	err := api.TimeTriggerStore.Delete(m)
+	if err != nil {
+		api.respondWithError(w, err)
+		return
+	}
+
+	api.respondWithSuccess(w, []byte(""))
+}