Refactor. Add Swagger UI docs.

Change from Gorilla mux to net/http

internal/api/server.go

@@ -0,0 +1,29 @@
+// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.
+// All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+package api
+
+import (
+	"crypto/ed25519"
+	"encoding/base64"
+	"log"
+	"net/http"
+
+	"github.com/ClusterCockpit/cc-metric-store/internal/config"
+)
+
+func MountRoutes(r *http.ServeMux) {
+	if len(config.Keys.JwtPublicKey) > 0 {
+		buf, err := base64.StdEncoding.DecodeString(config.Keys.JwtPublicKey)
+		if err != nil {
+			log.Fatalf("starting server failed: %v", err)
+		}
+		publicKey = ed25519.PublicKey(buf)
+	}
+
+	r.HandleFunc("POST /api/free/", handleFree)
+	r.HandleFunc("POST /api/write/", handleWrite)
+	r.HandleFunc("GET /api/query/", handleQuery)
+	r.HandleFunc("GET /api/debug/", handleDebug)
+}