Add static front end + functions endpoint.

gateway/server.go

@@ -1,22 +1,78 @@
 package main
 
 import (
+	"context"
+	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"net/http"
 	"time"
 
 	"github.com/alexellis/faas/gateway/metrics"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/client"
 	"github.com/gorilla/mux"
+	io_prometheus_client "github.com/prometheus/client_model/go"
 )
 
-func makeAlertHandler(c *client.Client) http.HandlerFunc {
+func makeAlertHandler() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		fmt.Println(c)
+		fmt.Println("Alert received.")
+		body, _ := ioutil.ReadAll(r.Body)
+		fmt.Println(string(body))
 		// Todo: parse alert, validate alert and scale up or down function
 
-		fmt.Println("Alert received.")
+		w.WriteHeader(http.StatusOK)
+	}
+}
+
+// Function exported for system/functions endpoint
+type Function struct {
+	Name            string  `json:"name"`
+	Image           string  `json:"image"`
+	InvocationCount float64 `json:"invocationCount"`
+	Replicas        uint64  `json:"replicas"`
+}
+
+func makeFunctionReader(metricsOptions metrics.MetricOptions, c *client.Client) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+
+		serviceFilter := filters.NewArgs()
+
+		options := types.ServiceListOptions{
+			Filters: serviceFilter,
+		}
+
+		services, err := c.ServiceList(context.Background(), options)
+		if err != nil {
+			fmt.Println(err)
+		}
+
+		// TODO: Filter only "faas" functions (via metadata?)
+
+		functions := make([]Function, 0)
+		for _, service := range services {
+			counter, _ := metricsOptions.GatewayFunctionInvocation.GetMetricWithLabelValues(service.Spec.Name)
+
+			var pbmetric io_prometheus_client.Metric
+			counter.Write(&pbmetric)
+			invocations := pbmetric.GetCounter().GetValue()
+
+			f := Function{
+				Name:            service.Spec.Name,
+				Image:           service.Spec.TaskTemplate.ContainerSpec.Image,
+				InvocationCount: invocations,
+				Replicas:        *service.Spec.Mode.Replicated.Replicas,
+			}
+			functions = append(functions, f)
+		}
+
+		functionBytes, _ := json.Marshal(functions)
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(200)
+		w.Write(functionBytes)
 	}
 }
 
@@ -33,12 +89,14 @@ func main() {
 
 	r := mux.NewRouter()
 	r.HandleFunc("/function/{name:[a-zA-Z_]+}", MakeProxy(metricsOptions, true, dockerClient))
-	r.HandleFunc("/system/alert", makeAlertHandler(dockerClient))
-	r.HandleFunc("/", MakeProxy(metricsOptions, false, dockerClient))
+	r.HandleFunc("/system/alert", makeAlertHandler())
+	r.HandleFunc("/system/functions", makeFunctionReader(metricsOptions, dockerClient)).Methods("GET")
+	r.HandleFunc("/", MakeProxy(metricsOptions, false, dockerClient)).Methods("POST")
 
 	metricsHandler := metrics.PrometheusHandler()
 	r.Handle("/metrics", metricsHandler)
 
+	r.PathPrefix("/").Handler(http.FileServer(http.Dir("./assets/"))).Methods("GET")
 	s := &http.Server{
 		Addr:           ":8080",
 		ReadTimeout:    8 * time.Second,