refactor refactor refactor

cmd/serve/api.go

@@ -0,0 +1,120 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/fs"
+	"net/http"
+
+	"git.yetaga.in/alazyreader/library/media"
+	"tailscale.com/client/tailscale"
+	"tailscale.com/util/must"
+)
+
+type Router struct {
+	static fs.FS
+	lib    Library
+	rcol   RecordCollection
+}
+
+type AdminRouter struct {
+	static fs.FS
+	lib    Library
+	ts     *tailscale.LocalClient
+}
+
+func writeError[T any](w http.ResponseWriter) func(t T, err error) (T, bool) {
+	return func(t T, err error) (T, bool) {
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+		}
+		return t, err != nil
+	}
+}
+
+func writeJSON(w http.ResponseWriter, b []byte, status int) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.WriteHeader(status)
+	w.Write(b)
+	w.Write([]byte("\n"))
+}
+
+func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	if req.URL.Path == "/api/records" {
+		RecordsAPIHandler(r.rcol).ServeHTTP(w, req)
+		return
+	}
+	if req.URL.Path == "/api/books" {
+		BooksAPIHandler(r.lib).ServeHTTP(w, req)
+		return
+	}
+	StaticHandler(r.static).ServeHTTP(w, req)
+}
+
+func (r *AdminRouter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	whois, _ := r.ts.WhoIs(req.Context(), req.RemoteAddr)
+	switch req.URL.Path {
+	case "/api/books":
+		switch req.Method {
+		case http.MethodGet:
+			books, ok := writeError[[]media.Book](w)(r.lib.GetAllBooks(req.Context()))
+			if !ok {
+				return
+			}
+			b, ok := writeError[[]byte](w)(json.Marshal(books))
+			if !ok {
+				return
+			}
+			writeJSON(w, b, http.StatusOK)
+		case http.MethodPost:
+		default:
+			badMethod(w)
+		}
+		return
+	}
+	w.Write([]byte(fmt.Sprintf("%+v", whois.UserProfile.DisplayName)))
+	// StaticHandler(r.static).ServeHTTP(w, req)
+}
+
+func badMethod(w http.ResponseWriter) {
+	writeJSON(w,
+		must.Get(json.Marshal(struct{ Error string }{Error: "method not supported"})),
+		http.StatusMethodNotAllowed)
+}
+
+func BooksAPIHandler(l Library) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		books, err := l.GetAllBooks(r.Context())
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		b, err := json.Marshal(books)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+
+		}
+		writeJSON(w, b, http.StatusOK)
+	})
+}
+
+func RecordsAPIHandler(l RecordCollection) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		books, err := l.GetAllRecords(r.Context())
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		b, err := json.Marshal(books)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		writeJSON(w, b, http.StatusOK)
+	})
+}
+
+func StaticHandler(f fs.FS) http.Handler {
+	return http.FileServer(http.FS(f))
+}

cmd/serve/main.go

@@ -2,11 +2,12 @@ package main
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
-	"io/fs"
 	"log"
+	"net"
 	"net/http"
+	"os"
+	"os/signal"
 	"strings"
 	"time"
 
@@ -16,8 +17,8 @@ import (
 	"git.yetaga.in/alazyreader/library/media"
 	"github.com/kelseyhightower/envconfig"
 	"golang.org/x/sync/errgroup"
-	"tailscale.com/client/tailscale"
 	"tailscale.com/tsnet"
+	"tailscale.com/util/must"
 )
 
 func obscureStr(in string, l int) string {
@@ -32,160 +33,123 @@ type RecordCollection interface {
 	GetAllRecords(context.Context) ([]media.Record, error)
 }
 
-type Router struct {
-	static fs.FS
-	lib    Library
-	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)
-	w.Write(b)
-	w.Write([]byte("\n"))
-}
-
-func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
-	if req.URL.Path == "/api/records" {
-		RecordsAPIHandler(r.rcol).ServeHTTP(w, req)
-		return
-	}
-	if req.URL.Path == "/api/books" {
-		BooksAPIHandler(r.lib).ServeHTTP(w, req)
-		return
-	}
-	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())
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-		b, err := json.Marshal(books)
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-
-		}
-		writeJSON(w, b, http.StatusOK)
-	})
-}
-
-func RecordsAPIHandler(l RecordCollection) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		books, err := l.GetAllRecords(r.Context())
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-		b, err := json.Marshal(books)
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-		writeJSON(w, b, http.StatusOK)
-	})
-}
-
-func StaticHandler(f fs.FS) http.Handler {
-	return http.FileServer(http.FS(f))
-}
-
 func main() {
 	var c config.Config
-	err := envconfig.Process("library", &c)
+	must.Do(envconfig.Process("library", &c))
-	if err != nil {
+
-		log.Fatalln(err)
-	}
-	f, err := frontend.Root()
-	if err != nil {
-		log.Fatalln(err)
-	}
 	var lib Library
+	var err error
 	if c.DBType == "memory" {
 		lib = &database.Memory{}
 	} else if c.DBType == "sql" {
-		if c.DBUser == "" || c.DBPass == "" || c.DBHost == "" || c.DBPort == "" || c.DBName == "" {
+		var latest, run int
-			if c.DBPass != "" {
+		lib, latest, run, err = setupSQL(c)
-				c.DBPass = obscureStr(c.DBPass, 3)
-			}
-			if c.DiscogsToken != "" {
-				c.DiscogsToken = obscureStr(c.DiscogsToken, 3)
-			}
-			log.Fatalf("vars: %+v", c)
-		}
-		sql, err := database.NewMySQLConnection(c.DBUser, c.DBPass, c.DBHost, c.DBPort, c.DBName)
 		if err != nil {
-			log.Fatalln(err)
+			log.Fatalf("err starting sql connection: %v", err)
-		}
-		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
-	}
-	discogsCache, err := database.NewDiscogsCache(c.DiscogsToken, time.Hour*24, c.DiscogsUser, c.DiscogsPersist, c.DiscogsCacheFile)
-	if err != nil {
-		log.Fatalln(err)
 	}
+	discogsCache := must.Get(database.NewDiscogsCache(
+		c.DiscogsToken, time.Hour*24, c.DiscogsUser, c.DiscogsPersist, c.DiscogsCacheFile,
+	))
+
+	frontendRoot := must.Get(frontend.Root())
+	adminRoot := must.Get(frontend.AdminRoot())
+
+	servers := make(chan (*http.Server), 2)
 	errGroup := errgroup.Group{}
-	errGroup.Go(func() error {
+	errGroup.Go(start(servers)(
-		return publicListener(8080, &Router{
+		publicServer(8080, &Router{
-			static: f,
+			static: frontendRoot,
 			lib:    lib,
 			rcol:   discogsCache,
-		})
+		})))
-	})
+	errGroup.Go(start(servers)(
-	errGroup.Go(func() error {
+		tailscaleListener("library-admin", &AdminRouter{
-		f, _ := frontend.AdminRoot()
+			static: adminRoot,
-		return tailscaleListener("library-admin", &AdminRouter{
-			static: f,
 			lib:    lib,
-		})
+		})))
-	})
+	errGroup.Go(shutdown(servers))
+
 	log.Println(errGroup.Wait())
 }
 
-func publicListener(port int, handler http.Handler) error {
+func setupSQL(c config.Config) (Library, int, int, error) {
-	log.Printf("Listening on http://0.0.0.0:%d/", port)
+	if c.DBUser == "" || c.DBPass == "" || c.DBHost == "" || c.DBPort == "" || c.DBName == "" {
-	return http.ListenAndServe(fmt.Sprintf(":%d", port), handler)
+		if c.DBPass != "" {
+			c.DBPass = obscureStr(c.DBPass, 3)
+		}
+		if c.DiscogsToken != "" {
+			c.DiscogsToken = obscureStr(c.DiscogsToken, 3)
+		}
+		return nil, 0, 0, fmt.Errorf("invalid config; vars provided: %+v", c)
+	}
+	sql, err := database.NewMySQLConnection(c.DBUser, c.DBPass, c.DBHost, c.DBPort, c.DBName)
+	if err != nil {
+		return nil, 0, 0, err
+	}
+	err = sql.PrepareDatabase(context.Background())
+	if err != nil {
+		return nil, 0, 0, err
+	}
+	latest, run, err := sql.RunMigrations(context.Background())
+	if err != nil {
+		return nil, 0, 0, err
+	}
+	return sql, latest, run, nil
 }
 
-func tailscaleListener(hostname string, handler *AdminRouter) error {
+func errFunc(err error) func() error {
+	return func() error { return err }
+}
+
+func start(servers chan (*http.Server)) func(*http.Server, net.Listener, error) func() error {
+	return func(s *http.Server, l net.Listener, err error) func() error {
+		if err != nil {
+			return errFunc(err)
+		}
+		servers <- s
+		return errFunc(s.Serve(l))
+	}
+}
+
+func shutdown(servers chan (*http.Server)) func() error {
+	sigint := make(chan os.Signal, 1)
+	signal.Notify(sigint, os.Interrupt)
+	<-sigint
+	close(servers)
+	for server := range servers {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+		if err := server.Shutdown(ctx); err != nil {
+			log.Panicf("error during shutdown: %v", err)
+		}
+		cancel()
+	}
+	return errFunc(nil)
+}
+
+func publicServer(port int, handler http.Handler) (*http.Server, net.Listener, error) {
+	server := &http.Server{Handler: handler}
+	ln, err := net.Listen("tcp", fmt.Sprintf(":%d", 8080))
+	if err != nil {
+		return nil, nil, err
+	}
+	return server, ln, nil
+}
+
+func tailscaleListener(hostname string, handler *AdminRouter) (*http.Server, net.Listener, 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, nil, err
-		return nil
 	}
 	handler.ts, err = s.LocalClient()
 	if err != nil {
-		return err
+		return nil, nil, err
 	}
-	return (&http.Server{Handler: handler}).Serve(ln)
+	server := &http.Server{Handler: handler}
+	return server, ln, nil
 }