[chore] The Big Middleware and API Refactor (tm) (#1250)

* interim commit: start refactoring middlewares into package under router

* another interim commit, this is becoming a big job

* another fucking massive interim commit

* refactor bookmarks to new style

* ambassador, wiz zeze commits you are spoiling uz

* she compiles, we're getting there

* we're just normal men; we're just innocent men

* apiutil

* whoopsie

* i'm glad noone reads commit msgs haha :blob_sweat:

* use that weirdo go-bytesize library for maxMultipartMemory

* fix media module paths

internal/middleware/logger.go

@@ -0,0 +1,99 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package middleware
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+
+	"codeberg.org/gruf/go-bytesize"
+	"codeberg.org/gruf/go-errors/v2"
+	"codeberg.org/gruf/go-kv"
+	"codeberg.org/gruf/go-logger/v2/level"
+	"github.com/gin-gonic/gin"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
+)
+
+// Logger returns a gin middleware which provides request logging and panic recovery.
+func Logger() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		// Initialize the logging fields
+		fields := make(kv.Fields, 6, 7)
+
+		// Determine pre-handler time
+		before := time.Now()
+
+		// defer so that we log *after the request has completed*
+		defer func() {
+			code := c.Writer.Status()
+			path := c.Request.URL.Path
+
+			if r := recover(); r != nil {
+				if c.Writer.Status() == 0 {
+					// No response was written, send a generic Internal Error
+					c.Writer.WriteHeader(http.StatusInternalServerError)
+				}
+
+				// Append panic information to the request ctx
+				err := fmt.Errorf("recovered panic: %v", r)
+				_ = c.Error(err)
+
+				// Dump a stacktrace to error log
+				callers := errors.GetCallers(3, 10)
+				log.WithField("stacktrace", callers).Error(err)
+			}
+
+			// NOTE:
+			// It is very important here that we are ONLY logging
+			// the request path, and none of the query parameters.
+			// Query parameters can contain sensitive information
+			// and could lead to storing plaintext API keys in logs
+
+			// Set request logging fields
+			fields[0] = kv.Field{"latency", time.Since(before)}
+			fields[1] = kv.Field{"clientIP", c.ClientIP()}
+			fields[2] = kv.Field{"userAgent", c.Request.UserAgent()}
+			fields[3] = kv.Field{"method", c.Request.Method}
+			fields[4] = kv.Field{"statusCode", code}
+			fields[5] = kv.Field{"path", path}
+
+			// Create log entry with fields
+			l := log.WithFields(fields...)
+
+			// Default is info
+			lvl := level.INFO
+
+			if code >= 500 {
+				// This is a server error
+				lvl = level.ERROR
+				l = l.WithField("error", c.Errors)
+			}
+
+			// Generate a nicer looking bytecount
+			size := bytesize.Size(c.Writer.Size())
+
+			// Finally, write log entry with status text body size
+			l.Logf(lvl, "%s: wrote %s", http.StatusText(code), size)
+		}()
+
+		// Process request
+		c.Next()
+	}
+}