Add input for receiving papertrail webhooks (#2038)

plugins/inputs/webhooks/papertrail/papertrail_webhooks.go

@@ -0,0 +1,79 @@
+package papertrail
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"time"
+
+	"github.com/gorilla/mux"
+	"github.com/influxdata/telegraf"
+)
+
+type PapertrailWebhook struct {
+	Path string
+	acc  telegraf.Accumulator
+}
+
+func (pt *PapertrailWebhook) Register(router *mux.Router, acc telegraf.Accumulator) {
+	router.HandleFunc(pt.Path, pt.eventHandler).Methods("POST")
+	log.Printf("I! Started the papertrail_webhook on %s", pt.Path)
+	pt.acc = acc
+}
+
+func (pt *PapertrailWebhook) eventHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Header.Get("Content-Type") != "application/x-www-form-urlencoded" {
+		http.Error(w, "Unsupported Media Type", http.StatusUnsupportedMediaType)
+		return
+	}
+
+	data := r.PostFormValue("payload")
+	if data == "" {
+		http.Error(w, "Bad Request", http.StatusBadRequest)
+		return
+	}
+
+	var payload Payload
+	err := json.Unmarshal([]byte(data), &payload)
+	if err != nil {
+		http.Error(w, "Bad Request", http.StatusBadRequest)
+		return
+	}
+
+	if payload.Events != nil {
+
+		// Handle event-based payload
+		for _, e := range payload.Events {
+			// Warning: Duplicate event timestamps will overwrite each other
+			tags := map[string]string{
+				"host":  e.Hostname,
+				"event": payload.SavedSearch.Name,
+			}
+			fields := map[string]interface{}{
+				"count": uint64(1),
+			}
+			pt.acc.AddFields("papertrail", fields, tags, e.ReceivedAt)
+		}
+
+	} else if payload.Counts != nil {
+
+		// Handle count-based payload
+		for _, c := range payload.Counts {
+			for ts, count := range *c.TimeSeries {
+				tags := map[string]string{
+					"host":  c.SourceName,
+					"event": payload.SavedSearch.Name,
+				}
+				fields := map[string]interface{}{
+					"count": count,
+				}
+				pt.acc.AddFields("papertrail", fields, tags, time.Unix(ts, 0))
+			}
+		}
+	} else {
+		http.Error(w, "Bad Request", http.StatusBadRequest)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+}