Refactor doctor (#12264)

* Refactor Logger

Refactor Logger to make a logger interface and make it possible to
wrap loggers for specific purposes.

* Refactor Doctor

    Move the gitea doctor functions into its own module.
    Use a logger for its messages instead of returning a results string[]

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Update modules/doctor/misc.go

Co-authored-by: 6543 <6543@obermui.de>

* Update modules/doctor/misc.go

Co-authored-by: 6543 <6543@obermui.de>

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

modules/doctor/authorizedkeys.go

@@ -0,0 +1,95 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package doctor
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+const tplCommentPrefix = `# gitea public key`
+
+func checkAuthorizedKeys(logger log.Logger, autofix bool) error {
+	if setting.SSH.StartBuiltinServer || !setting.SSH.CreateAuthorizedKeysFile {
+		return nil
+	}
+
+	fPath := filepath.Join(setting.SSH.RootPath, "authorized_keys")
+	f, err := os.Open(fPath)
+	if err != nil {
+		if !autofix {
+			logger.Critical("Unable to open authorized_keys file. ERROR: %v", err)
+			return fmt.Errorf("Unable to open authorized_keys file. ERROR: %v", err)
+		}
+		logger.Warn("Unable to open authorized_keys. (ERROR: %v). Attempting to rewrite...", err)
+		if err = models.RewriteAllPublicKeys(); err != nil {
+			logger.Critical("Unable to rewrite authorized_keys file. ERROR: %v", err)
+			return fmt.Errorf("Unable to rewrite authorized_keys file. ERROR: %v", err)
+		}
+	}
+	defer f.Close()
+
+	linesInAuthorizedKeys := map[string]bool{}
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, tplCommentPrefix) {
+			continue
+		}
+		linesInAuthorizedKeys[line] = true
+	}
+	f.Close()
+
+	// now we regenerate and check if there are any lines missing
+	regenerated := &bytes.Buffer{}
+	if err := models.RegeneratePublicKeys(regenerated); err != nil {
+		logger.Critical("Unable to regenerate authorized_keys file. ERROR: %v", err)
+		return fmt.Errorf("Unable to regenerate authorized_keys file. ERROR: %v", err)
+	}
+	scanner = bufio.NewScanner(regenerated)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, tplCommentPrefix) {
+			continue
+		}
+		if ok := linesInAuthorizedKeys[line]; ok {
+			continue
+		}
+		if !autofix {
+			logger.Critical(
+				"authorized_keys file %q is out of date.\nRegenerate it with:\n\t\"%s\"\nor\n\t\"%s\"",
+				fPath,
+				"gitea admin regenerate keys",
+				"gitea doctor --run authorized_keys --fix")
+			return fmt.Errorf(`authorized_keys is out of date and should be regenerated with "gitea admin regenerate keys" or "gitea doctor --run authorized_keys --fix"`)
+		}
+		logger.Warn("authorized_keys is out of date. Attempting rewrite...")
+		err = models.RewriteAllPublicKeys()
+		if err != nil {
+			logger.Critical("Unable to rewrite authorized_keys file. ERROR: %v", err)
+			return fmt.Errorf("Unable to rewrite authorized_keys file. ERROR: %v", err)
+		}
+	}
+	return nil
+}
+
+func init() {
+	Register(&Check{
+		Title:     "Check if OpenSSH authorized_keys file is up-to-date",
+		Name:      "authorized-keys",
+		IsDefault: true,
+		Run:       checkAuthorizedKeys,
+		Priority:  4,
+	})
+}