initial sketch of how this will work

cmd/serve/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"io/fs"
 	"log"
 	"net/http"
@@ -14,15 +15,11 @@ import (
 	"git.yetaga.in/alazyreader/library/frontend"
 	"git.yetaga.in/alazyreader/library/media"
 	"github.com/kelseyhightower/envconfig"
+	"golang.org/x/sync/errgroup"
+	"tailscale.com/client/tailscale"
+	"tailscale.com/tsnet"
 )
 
-func max(a, b int) int {
-	if a > b {
-		return a
-	}
-	return b
-}
-
 func obscureStr(in string, l int) string {
 	return in[0:max(l, len(in))] + strings.Repeat("*", max(0, len(in)-l))
 }
@@ -41,6 +38,12 @@ type Router struct {
 	rcol   RecordCollection
 }
 
+type AdminRouter struct {
+	static fs.FS
+	lib    Library
+	ts     *tailscale.LocalClient
+}
+
 func writeJSON(w http.ResponseWriter, b []byte, status int) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	w.WriteHeader(status)
@@ -60,6 +63,12 @@ func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	StaticHandler(r.static).ServeHTTP(w, req)
 }
 
+func (r *AdminRouter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	whois, _ := r.ts.WhoIs(req.Context(), req.RemoteAddr)
+	w.Write([]byte(fmt.Sprintf("%+v", whois.UserProfile.DisplayName)))
+	// StaticHandler(r.static).ServeHTTP(w, req)
+}
+
 func BooksAPIHandler(l Library) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		books, err := l.GetAllBooks(r.Context())
@@ -107,37 +116,76 @@ func main() {
 	if err != nil {
 		log.Fatalln(err)
 	}
-	if c.DBUser == "" || c.DBPass == "" || c.DBHost == "" || c.DBPort == "" || c.DBName == "" {
-		if c.DBPass != "" {
-			c.DBPass = obscureStr(c.DBPass, 3)
+	var lib Library
+	if c.DBType == "memory" {
+		lib = &database.Memory{}
+	} else if c.DBType == "sql" {
+		if c.DBUser == "" || c.DBPass == "" || c.DBHost == "" || c.DBPort == "" || c.DBName == "" {
+			if c.DBPass != "" {
+				c.DBPass = obscureStr(c.DBPass, 3)
+			}
+			if c.DiscogsToken != "" {
+				c.DiscogsToken = obscureStr(c.DiscogsToken, 3)
+			}
+			log.Fatalf("vars: %+v", c)
 		}
-		if c.DiscogsToken != "" {
-			c.DiscogsToken = obscureStr(c.DiscogsToken, 3)
+		sql, err := database.NewMySQLConnection(c.DBUser, c.DBPass, c.DBHost, c.DBPort, c.DBName)
+		if err != nil {
+			log.Fatalln(err)
 		}
-		log.Fatalf("vars: %+v", c)
+		err = sql.PrepareDatabase(context.Background())
+		if err != nil {
+			log.Fatalln(err)
+		}
+		latest, run, err := sql.RunMigrations(context.Background())
+		if err != nil {
+			log.Fatalln(err)
+		}
+		log.Printf("latest migration: %d; migrations run: %d", latest, run)
+		lib = sql
 	}
-	lib, err := database.NewMySQLConnection(c.DBUser, c.DBPass, c.DBHost, c.DBPort, c.DBName)
-	if err != nil {
-		log.Fatalln(err)
-	}
-	err = lib.PrepareDatabase(context.Background())
-	if err != nil {
-		log.Fatalln(err)
-	}
-	latest, run, err := lib.RunMigrations(context.Background())
-	if err != nil {
-		log.Fatalln(err)
-	}
-	log.Printf("latest migration: %d; migrations run: %d", latest, run)
 	discogsCache, err := database.NewDiscogsCache(c.DiscogsToken, time.Hour*24, c.DiscogsUser, c.DiscogsPersist, c.DiscogsCacheFile)
 	if err != nil {
 		log.Fatalln(err)
 	}
-	r := &Router{
-		static: f,
-		lib:    lib,
-		rcol:   discogsCache,
-	}
-	log.Println("Listening on http://0.0.0.0:8080/")
-	log.Fatalln(http.ListenAndServe(":8080", r))
+	errGroup := errgroup.Group{}
+	errGroup.Go(func() error {
+		return publicListener(8080, &Router{
+			static: f,
+			lib:    lib,
+			rcol:   discogsCache,
+		})
+	})
+	errGroup.Go(func() error {
+		f, _ := frontend.AdminRoot()
+		return tailscaleListener("library-admin", &AdminRouter{
+			static: f,
+			lib:    lib,
+		})
+	})
+	log.Println(errGroup.Wait())
+}
+
+func publicListener(port int, handler http.Handler) error {
+	log.Printf("Listening on http://0.0.0.0:%d/", port)
+	return http.ListenAndServe(fmt.Sprintf(":%d", port), handler)
+}
+
+func tailscaleListener(hostname string, handler *AdminRouter) error {
+	s := &tsnet.Server{
+		Dir:      ".config/" + hostname,
+		Hostname: hostname,
+	}
+	defer s.Close()
+
+	ln, err := s.Listen("tcp", ":80")
+	if err != nil {
+		fmt.Printf("%+v\n", err)
+		return nil
+	}
+	handler.ts, err = s.LocalClient()
+	if err != nil {
+		return err
+	}
+	return (&http.Server{Handler: handler}).Serve(ln)
 }