feat(backend): use custom logger

7 files changed, 96 insertions, 55 deletions

diff --git a/backend/admin.go b/backend/admin.go
index 087a3ea..9cb5376 100644
--- a/backend/admin.go
+++ b/backend/admin.go
@@ -1,7 +1,6 @@
 package backend
 
 import (
-	"log/slog"
 	"net/http"
 	"strconv"
 
@@ -33,7 +32,7 @@ func HandleAdmin(r *chi.Mux) {
 		if rawPage != "" {
 			page, err = strconv.Atoi(rawPage)
 			if err != nil || page < 1 {
-				slog.Warn("invalid page number", "rawPage", rawPage)
+				GetLogger(ctx).Warn("invalid page number", "requested", rawPage)
 				http.Error(w, "Bad request", http.StatusBadRequest)
 				return
 			}
diff --git a/backend/data.go b/backend/data.go
index 76c2ccc..3a8acf0 100644
--- a/backend/data.go
+++ b/backend/data.go
@@ -8,7 +8,6 @@ import (
 	"html/template"
 	"io"
 	"io/fs"
-	"log/slog"
 	"math/rand"
 	"net/http"
 	"regexp"
@@ -179,18 +178,19 @@ func getAsset(ctx context.Context, path string) *assetData {
 		return asset
 	}
 	asset = &assetData{}
+	logger := GetLogger(ctx)
 	var b []byte
 	if regexIsHttp.MatchString(path) {
 		asset.Src = path
 		resp, err := http.Get(path)
 		if err != nil {
-			slog.Warn("get remote asset", "error", err)
+			logger.Warn("get remote asset", "error", err)
 			return asset
 		}
 		defer resp.Body.Close()
 		b, err = io.ReadAll(resp.Body)
 		if err != nil {
-			slog.Warn("read remote asset", "error", err)
+			logger.Warn("read remote asset", "error", err)
 			return asset
 		}
 	} else {
@@ -199,7 +199,7 @@ func getAsset(ctx context.Context, path string) *assetData {
 		var err error
 		b, err = fs.ReadFile(aFS, path)
 		if err != nil {
-			slog.Warn("read asset", "error", err)
+			logger.Warn("read asset", "error", err)
 			return asset
 		}
 	}
diff --git a/backend/logger.go b/backend/logger.go
new file mode 100644
index 0000000..da5fadb
--- /dev/null
+++ b/backend/logger.go
@@ -0,0 +1,78 @@
+package backend
+
+import (
+	"context"
+	"log"
+	"log/slog"
+	"net/http"
+	"os"
+	"runtime/debug"
+)
+
+const (
+	loggerKey  = "logger"
+	statusCode = "status_code"
+)
+
+func GetLogger(ctx context.Context) *slog.Logger {
+	return ctx.Value(loggerKey).(*slog.Logger)
+}
+
+type customWriter struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+func (c *customWriter) WriteHeader(statusCode int) {
+	c.statusCode = statusCode
+	if statusCode != c.statusCode {
+		c.ResponseWriter.WriteHeader(statusCode)
+	}
+}
+
+func GetStatusCode(ctx context.Context) func() int {
+	return ctx.Value(statusCode).(func() int)
+}
+
+func SetLogger(l *slog.Logger) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			logger := l.With("uri", r.RequestURI, "method", r.Method)
+			ww := &customWriter{ResponseWriter: w, statusCode: http.StatusOK}
+			ctx := context.WithValue(r.Context(), statusCode, func() int {
+				return ww.statusCode
+			})
+			ctx = context.WithValue(ctx, loggerKey, logger)
+			defer func(logger *slog.Logger) {
+				rec := recover()
+				if rec == nil {
+					return
+				}
+				if rec == http.ErrAbortHandler {
+					panic(rec)
+				}
+				logger.Error("crashed, recovered", "error", rec, "status", http.StatusInternalServerError)
+				log.New(os.Stderr, "", 0).Printf("%s\n", debug.Stack())
+				http.Error(ww, "internal error", http.StatusInternalServerError)
+			}(logger)
+
+			next.ServeHTTP(ww, r.WithContext(ctx))
+
+			if ww.statusCode == http.StatusNotFound {
+				return
+			}
+			var lvl slog.Level
+			switch {
+			case ww.statusCode >= 500:
+				lvl = slog.LevelError
+			case ww.statusCode >= 400:
+				lvl = slog.LevelWarn
+			case ww.statusCode >= 300:
+				return
+			default:
+				lvl = slog.LevelInfo
+			}
+			logger.Log(context.Background(), lvl, "handled", "status", ww.statusCode)
+		})
+	}
+}
diff --git a/backend/router.go b/backend/router.go
index df5fb75..c742006 100644
--- a/backend/router.go
+++ b/backend/router.go
@@ -17,7 +17,6 @@ import (
 	"git.anhgelus.world/anhgelus/small-web/backend/storage"
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
-	"github.com/go-chi/httplog/v3"
 )
 
 const (
@@ -32,16 +31,13 @@ const (
 var templates embed.FS
 
 func SetupLogger(debug bool) {
-	logFormat := httplog.SchemaECS.Concise(!debug)
-
 	logLevel := slog.LevelInfo
 	if debug {
 		logLevel = slog.LevelDebug
 	}
 
 	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
-		ReplaceAttr: logFormat.ReplaceAttr,
-		Level:       logLevel,
+		Level: logLevel,
 	})).With(
 		slog.String("app", "anhgelus/small-web"),
 		slog.String("version", Version),
@@ -50,37 +46,11 @@ func SetupLogger(debug bool) {
 	slog.SetDefault(logger)
 }
 
-type customWriter struct {
-	http.ResponseWriter
-	statusCode int
-}
-
-func (c *customWriter) WriteHeader(statusCode int) {
-	c.statusCode = statusCode
-	c.ResponseWriter.WriteHeader(statusCode)
-}
-
 func NewRouter(debug bool, cfg *Config, db *sql.DB, assets fs.FS) *chi.Mux {
 	r := chi.NewRouter()
 
-	logLevel := slog.LevelWarn
-	if debug {
-		logLevel = slog.LevelDebug
-	}
-
 	r.Use(middleware.Timeout(30 * time.Second))
-	r.Use(httplog.RequestLogger(slog.Default(), &httplog.Options{
-		Level: logLevel,
-		// Set log output to Elastic Common Schema (ECS) format.
-		Schema:        httplog.SchemaECS.Concise(!debug),
-		RecoverPanics: true,
-		Skip: func(req *http.Request, respStatus int) bool {
-			return respStatus == http.StatusNotFound || respStatus == http.StatusMethodNotAllowed
-		},
-		// Optionally, log selected request/response headers explicitly.
-		LogRequestHeaders:  []string{"Origin"},
-		LogResponseHeaders: []string{},
-	}))
+	r.Use(SetLogger(slog.Default()))
 	// security headers
 	r.Use(func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -100,12 +70,13 @@ func NewRouter(debug bool, cfg *Config, db *sql.DB, assets fs.FS) *chi.Mux {
 			next.ServeHTTP(w, r)
 		})
 	})
+	// context
 	setContext := func(ctx context.Context) context.Context {
 		ctx = context.WithValue(ctx, configKey, cfg)
 		ctx = context.WithValue(ctx, assetsFSKey, assets)
 		ctx = context.WithValue(ctx, debugKey, debug)
 		return context.WithValue(ctx, storage.DBKey, db)
-	} // context
+	}
 	r.Use(func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			next.ServeHTTP(w, r.WithContext(
@@ -130,24 +101,20 @@ func NewRouter(debug bool, cfg *Config, db *sql.DB, assets fs.FS) *chi.Mux {
 	})
 	r.Use(func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			ww := &customWriter{ResponseWriter: w}
-			next.ServeHTTP(ww, r)
-			cfg := r.Context().Value(configKey).(*Config)
-			go func(cfg *Config, w *customWriter, r *http.Request) {
-				// because Go automatically adds http.StatusOK when not set
-				if w.statusCode == 0 {
-					w.statusCode = http.StatusOK
-				}
-				if w.statusCode >= 299 {
-					slog.Debug("not updating stats for status code above 299", "code", w.statusCode)
+			next.ServeHTTP(w, r)
+			go func(ctx context.Context, r *http.Request) {
+				statusCode := GetStatusCode(ctx)()
+				logger := GetLogger(ctx)
+				if statusCode >= 299 {
+					logger.Debug("not updating stats for status code above 299", "status", statusCode)
 					return
 				}
 				ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
 				defer cancel()
 				if err := storage.UpdateStats(setContext(ctx), r, cfg.Domain); err != nil {
-					slog.Error("updating stats", "error", err)
+					logger.Error("updating stats", "error", err)
 				}
-			}(cfg, ww, r)
+			}(r.Context(), r)
 		})
 	})
 
diff --git a/backend/section.go b/backend/section.go
index 1b5ab9f..5bbf558 100644
--- a/backend/section.go
+++ b/backend/section.go
@@ -269,7 +269,7 @@ func (s *Section) handlePagination(w http.ResponseWriter, r *http.Request, maxLo
 		var err error
 		page, err = strconv.Atoi(rawPage)
 		if err != nil || page < 1 {
-			slog.Warn("invalid page number", "rawPage", rawPage)
+			GetLogger(r.Context()).Warn("invalid page number", "requested", rawPage)
 			http.Error(w, "Bad request", http.StatusBadRequest)
 			return nil
 		}
diff --git a/go.mod b/go.mod
index 449f906..13cb181 100644
--- a/go.mod
+++ b/go.mod
@@ -4,7 +4,6 @@ go 1.25.1
 
 require (
 	github.com/go-chi/chi/v5 v5.2.3
-	github.com/go-chi/httplog/v3 v3.2.2
 	github.com/joho/godotenv v1.5.1
 	github.com/pelletier/go-toml/v2 v2.2.4
 )
diff --git a/go.sum b/go.sum
index 6f9f35f..08fbffe 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,5 @@
 github.com/go-chi/chi/v5 v5.2.3 h1:WQIt9uxdsAbgIYgid+BpYc+liqQZGMHRaUwp0JUcvdE=
 github.com/go-chi/chi/v5 v5.2.3/go.mod h1:L2yAIGWB3H+phAw1NxKwWM+7eUH/lU8pOMm5hHcoops=
-github.com/go-chi/httplog/v3 v3.2.2 h1:G0oYv3YYcikNjijArHFUlqfR78cQNh9fGT43i6StqVc=
-github.com/go-chi/httplog/v3 v3.2.2/go.mod h1:N/J1l5l1fozUrqIVuT8Z/HzNeSy8TF2EFyokPLe6y2w=
 github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
 github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
 github.com/mattn/go-sqlite3 v1.14.32 h1:JD12Ag3oLy1zQA+BNn74xRgaBbdhbNIDYvQUEuuErjs=