adding Dockerfile to repo

Dockerfile

@@ -0,0 +1,30 @@
+# get latest 1.15.8 golang
+FROM golang:1.15.8
+
+# create and set workingfolder
+WORKDIR /go/src/
+
+# download dependencies
+RUN go get -v -u -d github.com/gin-gonic/gin github.com/lib/pq github.com/eclipse/paho.mqtt.golang github.com/go-sql-driver/mysql
+
+# copy all sourcecode
+COPY src/ .
+
+# compile the program
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .
+
+
+# get latest alpine container
+FROM alpine:latest
+
+# add ca-certificates
+RUN apk --no-cache add ca-certificates
+
+# create workdir
+WORKDIR /root/
+
+# copy binary from first container
+COPY --from=0 /go/src/app .
+
+# run application
+CMD ["./app"]