add Dockerfile

Dockerfile

@@ -0,0 +1,12 @@
+FROM golang:latest 
+MAINTAINER Andreas Neue <an@dnix.de>
+
+RUN apt -y update && apt -y upgrade && apt-get install -y fortune vim tzdata ca-certificates && apt-get clean
+RUN ln -fs /usr/share/zoneinfo/Europe/Berlin /etc/localtime && dpkg-reconfigure -f noninteractive tzdata
+
+WORKDIR /go/src/covid-exporter
+COPY . .
+RUN go get -d -v  ./...
+RUN go install -v ./...
+
+CMD ["covid-exporter"]

main.go

@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 type CovidRecord struct {
@@ -127,6 +128,6 @@ func serveMetrics() {
 	)
 	prometheus.MustRegister(gaugePopulation)
 
-	http.Handle("/metrics", prometheus.Handler())
+	http.Handle("/metrics", promhttp.Handler())
 	http.ListenAndServe(":9099", nil)
 }