Mulitple Gitea Doctor improvements (#10943)

* Add `gitea doctor --list` flag to list the checks that will be run, including those by default
* Add `gitea doctor --run` to run specific checks
* Add `gitea doctor --all` to run all checks
* Add db version checker
* Add non-default recalculate merge bases check/fixer to doctor
* Add hook checker (Fix #9878) and ensure hooks are executable (Fix #6319)
* Fix authorized_keys checker - slight change of functionality here because parsing the command is fragile and we should just check if the authorized_keys file is essentially the same as what gitea would produce. (This is still not perfect as order matters - we should probably just md5sum the two files.)
* Add SCRIPT_TYPE check (Fix #10977)
* Add `gitea doctor --fix` to attempt to fix what is possible to easily fix
* Add `gitea doctor --log-file` to set the log-file, be it a file, stdout or to switch off completely. (Fixes previously undetected bug with certain xorm logging configurations - see @6543 comment.)

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

models/ssh_key.go

@@ -15,6 +15,7 @@ import (
 	"encoding/pem"
 	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"math/big"
 	"os"
@@ -701,7 +702,21 @@ func rewriteAllPublicKeys(e Engine) error {
 		}
 	}
 
-	err = e.Iterate(new(PublicKey), func(idx int, bean interface{}) (err error) {
+	if err := regeneratePublicKeys(e, t); err != nil {
+		return err
+	}
+
+	t.Close()
+	return os.Rename(tmpPath, fPath)
+}
+
+// RegeneratePublicKeys regenerates the authorized_keys file
+func RegeneratePublicKeys(t io.StringWriter) error {
+	return regeneratePublicKeys(x, t)
+}
+
+func regeneratePublicKeys(e Engine, t io.StringWriter) error {
+	err := e.Iterate(new(PublicKey), func(idx int, bean interface{}) (err error) {
 		_, err = t.WriteString((bean.(*PublicKey)).AuthorizedString())
 		return err
 	})
@@ -709,6 +724,7 @@ func rewriteAllPublicKeys(e Engine) error {
 		return err
 	}
 
+	fPath := filepath.Join(setting.SSH.RootPath, "authorized_keys")
 	if com.IsExist(fPath) {
 		f, err := os.Open(fPath)
 		if err != nil {
@@ -729,9 +745,7 @@ func rewriteAllPublicKeys(e Engine) error {
 		}
 		f.Close()
 	}
-
-	t.Close()
-	return os.Rename(tmpPath, fPath)
+	return nil
 }
 
 // ________                .__                 ____  __.