start on api

Signed-off-by: Evan Hazlett <ejhazlett@gmail.com>

server/handler.go

@@ -0,0 +1,12 @@
+package server
+
+import (
+	"net/http"
+
+	"github.com/ehazlett/element/version"
+)
+
+func (s *Server) getRequestHandler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Server", "element "+version.FullVersion())
+	w.WriteHeader(http.StatusOK)
+}

server/routes.go

@@ -0,0 +1,12 @@
+package server
+
+import (
+	"github.com/gorilla/mux"
+)
+
+func (s *Server) router() (*mux.Router, error) {
+	r := mux.NewRouter()
+	r.HandleFunc("/", s.getRequestHandler).Methods("GET")
+
+	return r, nil
+}

server/server.go

@@ -0,0 +1,44 @@
+package server
+
+import (
+	"net/http"
+
+	"github.com/ehazlett/element/config"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/sirupsen/logrus"
+)
+
+type Server struct {
+	cfg *config.Config
+}
+
+func NewServer(cfg *config.Config) (*Server, error) {
+	return &Server{
+		cfg: cfg,
+	}, nil
+}
+
+func (s *Server) Run() error {
+	if s.cfg.EnableMetrics {
+		// start prometheus listener
+		http.Handle("/metrics", prometheus.Handler())
+		go func() {
+			if err := http.ListenAndServe(s.cfg.ListenAddr, nil); err != nil {
+				logrus.Error("unable to start metric listener: %s", err)
+			}
+		}()
+	}
+
+	r, err := s.router()
+	if err != nil {
+		return err
+	}
+
+	http.Handle("/", r)
+
+	if err := http.ListenAndServe(s.cfg.ListenAddr, nil); err != nil {
+		return err
+	}
+
+	return nil
+}