Added JSON output

README.md

@@ -23,3 +23,9 @@ Usage of ./certcheck:
 PromCertcheck dev...
 Starting to listen on 0.0.0.0:3000
 ```
+
+## URLs
+
+- `/` - Shows you a human readable version of the check data
+- `/metrics` - Prometheus compatible output of the check data
+- `/results.json` - Gives you a JSON version of the check results including certificate details

http.go

@@ -3,13 +3,14 @@ package main
 //go:generate go-bindata display.html
 
 import (
+	"encoding/json"
 	"log"
 	"net/http"
 
 	"github.com/flosch/pongo2"
 )
 
-func httpHandler(res http.ResponseWriter, r *http.Request) {
+func htmlHandler(res http.ResponseWriter, r *http.Request) {
 	tplsrc, _ := Asset("display.html")
 
 	template, err := pongo2.FromString(string(tplsrc))
@@ -24,3 +25,8 @@ func httpHandler(res http.ResponseWriter, r *http.Request) {
 		"version":                version,
 	}, res)
 }
+
+func jsonHandler(res http.ResponseWriter, r *http.Request) {
+	res.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(res).Encode(probeMonitors)
+}

main.go

@@ -28,8 +28,8 @@ var (
 )
 
 type probeMonitor struct {
-	IsValid     prometheus.Gauge
-	Expires     prometheus.Gauge
+	IsValid     prometheus.Gauge `json:"-"`
+	Expires     prometheus.Gauge `json:"-"`
 	Status      probeResult
 	Certificate *x509.Certificate
 }
@@ -66,7 +66,8 @@ func main() {
 
 	r := mux.NewRouter()
 	r.Handle("/metrics", prometheus.Handler())
-	r.HandleFunc("/", httpHandler)
+	r.HandleFunc("/", htmlHandler)
+	r.HandleFunc("/results.json", jsonHandler)
 	http.ListenAndServe(":3000", r)
 }