feat(smalltrip): logger middleware

This commit is contained in:
Guz
2025-02-24 08:03:53 -03:00
parent 9fbe24cc5c
commit 7593ba9870

View File

@@ -0,0 +1,275 @@
package middleware
import (
"fmt"
"log/slog"
"math/rand"
"net"
"net/http"
)
const (
defaultMsgNew = "NEW REQUEST"
defaultMsg200 = "END REQUEST"
defaultMsg400 = "INV REQUEST"
defaultMsg500 = "ERR REQUEST"
)
func Logger(logger *slog.Logger, options ...LoggerOption) Middleware {
state := &loggerState{
levelNew: slog.LevelDebug,
msgNew: "",
argsNew: LoggerArgsDefault,
level200: -1,
msg200: "",
args200: LoggerArgsDefault,
level400: -1,
msg400: "",
args400: LoggerArgsDefault,
level500: -1,
msg500: "",
args500: LoggerArgsDefault,
hashFunction: randHash,
logger: logger,
}
for _, option := range options {
option(state)
}
if state.level200 == -1 {
state.level200 = state.levelNew + 4
}
if state.level400 == -1 {
state.level400 = state.level200 + 4
}
if state.level500 == -1 {
state.level500 = state.level500 + 4
}
if state.msgNew == "" {
state.msgNew = defaultMsgNew
}
if state.msg200 == "" {
if state.msgNew != "" && state.msgNew != defaultMsgNew {
state.msg200 = state.msgNew
} else {
state.msg200 = defaultMsg200
}
}
if state.msg400 == "" {
if state.msg200 != "" && state.msg200 != defaultMsg200 {
state.msg400 = state.msg200
} else {
state.msg400 = defaultMsg400
}
}
if state.msg500 == "" {
if state.msg400 != "" && state.msg400 != defaultMsg400 {
state.msg500 = state.msg400
} else {
state.msg500 = defaultMsg500
}
}
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
id := randHash(5)
state.logger = logger.With(slog.String("id", id))
lw := &loggerResponseWriter{w, 0}
state.lNew(state.argsNew(lw, r)...)
next.ServeHTTP(lw, r)
switch {
case lw.StatusCode() >= 500:
state.l500(state.args500(lw, r)...)
case lw.StatusCode() >= 400:
state.l400(state.args400(lw, r)...)
default:
state.l200(state.args200(lw, r)...)
}
})
}
}
type LoggerOption func(*loggerState)
func LoggerWithLevel(l slog.Level) LoggerOption {
return func(ls *loggerState) { ls.levelNew = l }
}
func LoggerWithMsg(msg string) LoggerOption {
return func(ls *loggerState) { ls.msgNew = msg }
}
func LoggerWithArgs(args LoggerArgs) LoggerOption {
return func(ls *loggerState) { ls.argsNew = args }
}
func LoggerWith200Level(l slog.Level) LoggerOption {
return func(ls *loggerState) { ls.level200 = l }
}
func LoggerWith200Msg(msg string) LoggerOption {
return func(ls *loggerState) { ls.msg200 = msg }
}
func LoggerWith200Args(args LoggerArgs) LoggerOption {
return func(ls *loggerState) { ls.args200 = args }
}
func LoggerWith400Level(l slog.Level) LoggerOption {
return func(ls *loggerState) { ls.level400 = l }
}
func LoggerWith400Msg(msg string) LoggerOption {
return func(ls *loggerState) { ls.msg400 = msg }
}
func LoggerWith400Args(args LoggerArgs) LoggerOption {
return func(ls *loggerState) { ls.args400 = args }
}
func LoggerWith500Level(l slog.Level) LoggerOption {
return func(ls *loggerState) { ls.level500 = l }
}
func LoggerWith500Msg(msg string) LoggerOption {
return func(ls *loggerState) { ls.msg500 = msg }
}
func LoggerWith500Args(args LoggerArgs) LoggerOption {
return func(ls *loggerState) { ls.args500 = args }
}
type LoggerArgs func(LoggerResponseWriter, *http.Request) []any
func LoggerArgsDefault(lw LoggerResponseWriter, r *http.Request) []any {
addr := LoggerGetAddr(r)
if net.ParseIP(addr) == nil {
addr = fmt.Sprintf("INVALID ADDR %s", addr)
}
return []any{
slog.String("status", fmt.Sprintf("%3d", lw.StatusCode())),
slog.String("method", fmt.Sprintf("%3s", r.Method)),
slog.String("addr", addr),
slog.String("path", r.URL.Path),
}
}
func LoggerGetAddr(r *http.Request) string {
if i := r.Header.Get("CF-Connecting-IP"); i != "" {
return i
}
if i := r.Header.Get("X-Forwarded-For"); i != "" {
return i
}
if i := r.Header.Get("X-Real-IP"); i != "" {
return i
}
return r.RemoteAddr
}
type LoggerResponseWriter interface {
http.ResponseWriter
StatusCode() int
}
type loggerResponseWriter struct {
http.ResponseWriter
statusCode int
}
func (w *loggerResponseWriter) WriteHeader(s int) {
w.statusCode = s
w.ResponseWriter.WriteHeader(s)
}
func (w *loggerResponseWriter) StatusCode() int {
return w.statusCode
}
type loggerState struct {
levelNew slog.Level
msgNew string
argsNew LoggerArgs
level200 slog.Level
msg200 string
args200 LoggerArgs
level400 slog.Level
msg400 string
args400 LoggerArgs
level500 slog.Level
msg500 string
args500 LoggerArgs
hashFunction func(n int) string
logger *slog.Logger
}
func (l *loggerState) lNew(args ...any) {
l.logLevel(l.levelNew, l.msgNew, args...)
}
func (l *loggerState) l200(args ...any) {
l.logLevel(l.level200, l.msg200, args...)
}
func (l *loggerState) l400(args ...any) {
l.logLevel(l.level400, l.msg400, args...)
}
func (l *loggerState) l500(args ...any) {
l.logLevel(l.level500, l.msg500, args...)
}
func (l *loggerState) logLevel(level slog.Level, msg string, args ...any) {
switch true {
case level >= slog.LevelError:
l.logger.Error(msg, args...)
case level >= slog.LevelWarn:
l.logger.Warn(msg, args...)
case level >= slog.LevelInfo:
l.logger.Info(msg, args...)
default:
l.logger.Debug(msg, args...)
}
}
func getBiggestLength(s ...string) int {
var l int
for _, s := range s {
if len(s) > l {
l = len(s)
}
}
return l
}
const HASH_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
// This is not the most performant function, as a TODO we could
// improve based on this Stackoberflow thread:
// https://stackoverflow.com/questions/22892120/how-to-generate-a-random-string-of-a-fixed-length-in-go
func randHash(n int) string {
b := make([]byte, n)
for i := range b {
b[i] = HASH_CHARS[rand.Int63()%int64(len(HASH_CHARS))]
}
return string(b)
}