built a simple feature-complete metrics bundler

1 files changed, 84 insertions, 0 deletions

diff --git a/main.go b/main.go
new file mode 100644
index 0000000..32e572b
--- /dev/null
+++ b/main.go
@@ -0,0 +1,84 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"github.com/gorilla/mux"
+	"log"
+	"net/http"
+	"strconv"
+)
+
+var (
+	metrics map[string]float64
+)
+
+func metricsHandler(w http.ResponseWriter, r *http.Request) {
+
+	// if the request method is GET, return all metrics
+	if r.Method == "GET" {
+
+		// if the length of the metrics map is zero, return some information on how to add metrics
+		if len(metrics) == 0 {
+			returnString := "Add metrics by making a post request to this endpoint\n" +
+				"curl -X POST --data = \"\" <url>:<port>/meetrics"
+
+			_, _ = fmt.Fprintf(w, returnString)
+
+		} else {
+			// return all the metrics
+			for key, value := range metrics {
+				_, _ = fmt.Fprintf(w, "%s %f\n", key, value)
+			}
+
+		}
+
+		// if the request method is POST, add the posted metrics to the metrics map
+	} else if r.Method == "POST" {
+
+		// parse the POST form
+		errParseForm := r.ParseForm()
+		if errParseForm != nil {
+			panic(errParseForm)
+		}
+
+		// parse the parameters
+		key := r.Form.Get("key")
+		value, parseFloatErr := strconv.ParseFloat(r.Form.Get("value"), 64)
+		if parseFloatErr != nil {
+			log.Printf("Error parsing %v", value)
+		}
+
+		// if the metrics var does not exist yet, create it
+		if metrics == nil {
+			metrics = map[string]float64{}
+		}
+
+		// assign the value to the key
+		metrics[key] = value
+
+		_, _ = fmt.Fprintf(w, "added the metrics")
+
+		// return an error
+	} else {
+		log.Println("Error, the handler was neither accessed using a GET or a POST request!")
+
+	}
+}
+
+func main() {
+
+	// parse some command line flags
+	var port string
+	flag.StringVar(&port, "p", "8080", "port used to host the service")
+	flag.Parse()
+	log.Println("[ ] Done loading the flags")
+
+	// setup a new router and define routes
+	r := mux.NewRouter()
+	r.HandleFunc("/metrics", metricsHandler).Methods("GET", "POST")
+
+	// start the http server
+	log.Printf("Starting the http server on port %s", port)
+	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), r))
+}