Initial commit

Dockerfile

@@ -0,0 +1,21 @@
+FROM golang:latest as build
+
+RUN mkdir -p /go/src/greet
+WORKDIR /go/src/greet
+
+RUN go get -d github.com/gorilla/mux && \
+	go get -d github.com/prometheus/client_golang/prometheus && \
+    go get -d github.com/prometheus/client_golang/prometheus/promhttp
+
+COPY main.go . 
+
+RUN CGO_ENABLED=0 go build -a -installsuffix cgo --ldflags "-s -w" -o /usr/bin/server 
+
+FROM alpine
+
+COPY --from=build /usr/bin/server /root/
+
+EXPOSE 8080
+WORKDIR /root/
+
+CMD ["./server"]

main.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"time"
+	"net/http"
+
+	"github.com/gorilla/mux"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+func SayHello(greeting_summary *prometheus.SummaryVec) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		start := time.Now()
+		defer r.Body.Close()
+		code := 500
+
+		defer func() {
+			httpDuration := time.Since(start)
+			greeting_summary.WithLabelValues("duration").Observe(httpDuration.Seconds())
+		}()
+
+		code = http.StatusBadRequest
+		if r.Method == "GET" {
+			code = http.StatusOK
+			vars := mux.Vars(r)
+			name := vars["name"]
+			if (name == "slow") {
+				time.Sleep(10 * time.Second)
+			}
+
+			greet := fmt.Sprintf("Hello %s \n", name)
+			w.Write([]byte(greet))
+		} else {
+			w.WriteHeader(code)
+		}
+	}
+}
+
+func main() {
+	greeting_summary := prometheus.NewSummaryVec(prometheus.SummaryOpts{
+		Name: "greeting_seconds",
+		Help: "Time taken for greeting request",
+	}, []string{"greetings"})
+
+	router := mux.NewRouter()
+	router.Handle("/hello/{name}", SayHello(greeting_summary))
+	router.Handle("/metrics", promhttp.Handler())
+	prometheus.Register(greeting_summary)
+	log.Fatal(http.ListenAndServe(":8080", router))
+}