Webhooks plugin: add mandrill (#1408)

* Add mandrill webhook.

* Store the id of the msg as part of event.

Signed-off-by: Cyril Duez <cyril@stormz.me>
Signed-off-by: François de Metz <francois@stormz.me>

* Decode body to get the mandrill_events.

Signed-off-by: Cyril Duez <cyril@stormz.me>
Signed-off-by: François de Metz <francois@stormz.me>

* Handle HEAD request.

Signed-off-by: Cyril Duez <cyril@stormz.me>
Signed-off-by: François de Metz <francois@stormz.me>

* Add the README.

Signed-off-by: Cyril Duez <cyril@stormz.me>
Signed-off-by: François de Metz <francois@stormz.me>

* Add mandrill_webhooks to the README.

Signed-off-by: Cyril Duez <cyril@stormz.me>
Signed-off-by: François de Metz <francois@stormz.me>

* Update changelog.

Signed-off-by: Cyril Duez <cyril@stormz.me>
Signed-off-by: François de Metz <francois@stormz.me>

* Run gofmt.

Signed-off-by: Cyril Duez <cyril@stormz.me>
Signed-off-by: François de Metz <francois@stormz.me>

plugins/inputs/webhooks/mandrill/mandrill_webhooks.go

@@ -0,0 +1,56 @@
+package mandrill
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/gorilla/mux"
+	"github.com/influxdata/telegraf"
+)
+
+type MandrillWebhook struct {
+	Path string
+	acc  telegraf.Accumulator
+}
+
+func (md *MandrillWebhook) Register(router *mux.Router, acc telegraf.Accumulator) {
+	router.HandleFunc(md.Path, md.returnOK).Methods("HEAD")
+	router.HandleFunc(md.Path, md.eventHandler).Methods("POST")
+
+	log.Printf("Started the webhooks_mandrill on %s\n", md.Path)
+	md.acc = acc
+}
+
+func (md *MandrillWebhook) returnOK(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusOK)
+}
+
+func (md *MandrillWebhook) eventHandler(w http.ResponseWriter, r *http.Request) {
+	defer r.Body.Close()
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+	data, err := url.ParseQuery(string(body))
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+	var events []MandrillEvent
+	err = json.Unmarshal([]byte(data.Get("mandrill_events")), &events)
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	for _, event := range events {
+		md.acc.AddFields("mandrill_webhooks", event.Fields(), event.Tags(), time.Unix(event.TimeStamp, 0))
+	}
+
+	w.WriteHeader(http.StatusOK)
+}