Fix all possible setting error related storages and added some tests (#23911)

Follow up #22405

Fix #20703 

This PR rewrites storage configuration read sequences with some breaks
and tests. It becomes more strict than before and also fixed some
inherit problems.

- Move storage's MinioConfig struct into setting, so after the
configuration loading, the values will be stored into the struct but not
still on some section.
- All storages configurations should be stored on one section,
configuration items cannot be overrided by multiple sections. The
prioioty of configuration is `[attachment]` > `[storage.attachments]` |
`[storage.customized]` > `[storage]` > `default`
- For extra override configuration items, currently are `SERVE_DIRECT`,
`MINIO_BASE_PATH`, `MINIO_BUCKET`, which could be configured in another
section. The prioioty of the override configuration is `[attachment]` >
`[storage.attachments]` > `default`.
- Add more tests for storages configurations.
- Update the storage documentations.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/storage/minio.go

@@ -16,6 +16,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/minio/minio-go/v7"
@@ -41,25 +42,9 @@ func (m *minioObject) Stat() (os.FileInfo, error) {
 	return &minioFileInfo{oi}, nil
 }
 
-// MinioStorageType is the type descriptor for minio storage
-const MinioStorageType Type = "minio"
-
-// MinioStorageConfig represents the configuration for a minio storage
-type MinioStorageConfig struct {
-	Endpoint           string `ini:"MINIO_ENDPOINT"`
-	AccessKeyID        string `ini:"MINIO_ACCESS_KEY_ID"`
-	SecretAccessKey    string `ini:"MINIO_SECRET_ACCESS_KEY"`
-	Bucket             string `ini:"MINIO_BUCKET"`
-	Location           string `ini:"MINIO_LOCATION"`
-	BasePath           string `ini:"MINIO_BASE_PATH"`
-	UseSSL             bool   `ini:"MINIO_USE_SSL"`
-	InsecureSkipVerify bool   `ini:"MINIO_INSECURE_SKIP_VERIFY"`
-	ChecksumAlgorithm  string `ini:"MINIO_CHECKSUM_ALGORITHM"`
-}
-
 // MinioStorage returns a minio bucket storage
 type MinioStorage struct {
-	cfg      *MinioStorageConfig
+	cfg      *setting.MinioStorageConfig
 	ctx      context.Context
 	client   *minio.Client
 	bucket   string
@@ -87,13 +72,8 @@ func convertMinioErr(err error) error {
 }
 
 // NewMinioStorage returns a minio storage
-func NewMinioStorage(ctx context.Context, cfg interface{}) (ObjectStorage, error) {
-	configInterface, err := toConfig(MinioStorageConfig{}, cfg)
-	if err != nil {
-		return nil, convertMinioErr(err)
-	}
-	config := configInterface.(MinioStorageConfig)
-
+func NewMinioStorage(ctx context.Context, cfg *setting.Storage) (ObjectStorage, error) {
+	config := cfg.MinioConfig
 	if config.ChecksumAlgorithm != "" && config.ChecksumAlgorithm != "default" && config.ChecksumAlgorithm != "md5" {
 		return nil, fmt.Errorf("invalid minio checksum algorithm: %s", config.ChecksumAlgorithm)
 	}
@@ -258,5 +238,5 @@ func (m *MinioStorage) IterateObjects(dirName string, fn func(path string, obj O
 }
 
 func init() {
-	RegisterStorageType(MinioStorageType, NewMinioStorage)
+	RegisterStorageType(setting.MinioStorageType, NewMinioStorage)
 }