Dump github/gitlab/gitea repository data to a local directory and restore to gitea (#12244)

* Dump github/gitlab repository data to a local directory

* Fix lint

* Adjust directory structure

* Allow migration special units

* Allow migration ignore release assets

* Fix lint

* Add restore repository

* stage the changes

* Merge

* Fix lint

* Update the interface

* Add some restore methods

* Finish restore

* Add comments

* Fix restore

* Add a token flag

* Fix bug

* Fix test

* Fix test

* Fix bug

* Fix bug

* Fix lint

* Fix restore

* refactor downloader

* fmt

* Fix bug isEnd detection on getIssues

* Refactor maxPerPage

* Remove unused codes

* Remove unused codes

* Fix bug

* Fix restore

* Fix dump

* Uploader should not depend downloader

* use release attachment name but not id

* Fix restore bug

* Fix lint

* Fix restore bug

* Add a method of DownloadFunc for base.Release to make uploader not depend on downloader

* fix Release yml marshal

* Fix trace information

* Fix bug when dump & restore

* Save relative path on yml file

* Fix bug

* Use relative path

* Update docs

* Use git service string but not int

* Recognize clone addr to service type

modules/migrations/base/release.go

@@ -4,32 +4,37 @@
 
 package base
 
-import "time"
+import (
+	"io"
+	"time"
+)
 
 // ReleaseAsset represents a release asset
 type ReleaseAsset struct {
 	ID            int64
 	Name          string
-	ContentType   *string
+	ContentType   *string `yaml:"content_type"`
 	Size          *int
-	DownloadCount *int
+	DownloadCount *int `yaml:"download_count"`
 	Created       time.Time
 	Updated       time.Time
-	DownloadURL   *string
+	DownloadURL   *string `yaml:"download_url"`
+	// if DownloadURL is nil, the function should be invoked
+	DownloadFunc func() (io.ReadCloser, error) `yaml:"-"`
 }
 
 // Release represents a release
 type Release struct {
-	TagName         string
-	TargetCommitish string
+	TagName         string `yaml:"tag_name"`
+	TargetCommitish string `yaml:"target_commitish"`
 	Name            string
 	Body            string
 	Draft           bool
 	Prerelease      bool
-	PublisherID     int64
-	PublisherName   string
-	PublisherEmail  string
-	Assets          []ReleaseAsset
+	PublisherID     int64  `yaml:"publisher_id"`
+	PublisherName   string `yaml:"publisher_name"`
+	PublisherEmail  string `yaml:"publisher_email"`
+	Assets          []*ReleaseAsset
 	Created         time.Time
 	Published       time.Time
 }