记一次gitlab代码仓库迁移_git clone --mirror

背景

一个维护了将近三年的php项目，最近需要交给工程组的同事维护，需要把我们成都内网的gitlab仓库的一些项目同步一份到武汉gitlab仓库。可能后续，还会再次同步更新。（成都仓库可能发生新的commit，需要把最新的变动同步到武汉仓库）

所以，这里就需要用到git clone --mirror old.git的相关命令，来完成代码仓库的镜像同步操作。

最终的效果是，迁移后的仓库内容是包含了现有分支的所有commit、merge等分支上的变动历史记录！这些记录就是这些代码的前世今生！

下面正文部分就是记录本次迁移所使用到的相关命令，以及一些git命令报错的原因定位+解决方法。

正文

把大象放进冰箱的步骤：

1.在新gitlab服务器上确保你有相关权限可以创建一个项目

新建完毕，长这个样子：

目前这个仓库是个空的！没关系，我们要的效果就是空的！因为我们把另外一个gitlab服务器上的特定项目用来同步到这个空项目！如果不是空的反而会踩一些坑，后面举例说明！

2.在你电脑上找一个目录，在此目录打开git bash的命令行交互窗口

注意：xxx.git的东西是已经同步了仓库信息的历史镜像文件，你的在此应该就是s9-migrate的空目录！

在git bash的命令行窗口依次输入：

wzp@DESKTOP-8HFQM2M MINGW64 /e/临时导出/s9-migrate
$ git clone --mirror http://10.251.9.191/open-v/section9-config.git
Cloning into bare repository 'section9-config.git'...
remote: Enumerating objects: 1221, done.
remote: Counting objects: 100% (1221/1221), done.
remote: Compressing objects: 100% (529/529), done.
remote: Total 1221 (delta 694), reused 1166 (delta 653)
Receiving objects: 100% (1221/1221), 866.71 KiB | 10.44 MiB/s, done.
Resolving deltas: 100% (694/694), done.
 
wzp@DESKTOP-8HFQM2M MINGW64 /e/临时导出/s9-migrate
$ ls
section9-api.git/  section9-config.git/
 
wzp@DESKTOP-8HFQM2M MINGW64 /e/临时导出/s9-migrate
$ cd section9-config.git
 
wzp@DESKTOP-8HFQM2M MINGW64 /e/临时导出/s9-migrate/section9-config.git (BARE:master)
$ git remote set-url --push origin https://code.avlyun.org/victory/section9/config.git
 
wzp@DESKTOP-8HFQM2M MINGW64 /e/临时导出/s9-migrate/section9-config.git (BARE:master)
$ git push --mirror https://code.avlyun.org/victory/section9/config.git
Counting objects: 1221, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (488/488), done.
Writing objects: 100% (1221/1221), 866.71 KiB | 78.79 MiB/s, done.
Total 1221 (delta 694), reused 1221 (delta 694)
remote: Resolving deltas: 100% (694/694), done.
remote:
remote: To create a merge request for docker-config-paas, visit:
remote:   https://code.avlyun.org/victory/section9/config/-/merge_requests/new?merge_request%5Bsource_branch%5D=docker-config-paas
remote:
remote:
remote: To create a merge request for docker-config-prod, visit:
remote:   https://code.avlyun.org/victory/section9/config/-/merge_requests/new?merge_request%5Bsource_branch%5D=docker-config-prod
remote:
remote:
remote: To create a merge request for docker-config-qa, visit:
remote:   https://code.avlyun.org/victory/section9/config/-/merge_requests/new?merge_request%5Bsource_branch%5D=docker-config-qa
remote:
remote:
remote: To create a merge request for docker-config-staging, visit:
remote:   https://code.avlyun.org/victory/section9/config/-/merge_requests/new?merge_request%5Bsource_branch%5D=docker-config-staging
remote:
remote:
remote: To create a merge request for docker-config-xz, visit:
remote:   https://code.avlyun.org/victory/section9/config/-/merge_requests/new?merge_request%5Bsource_branch%5D=docker-config-xz
remote:
To https://code.avlyun.org/victory/section9/config.git
 + f05c224...d344e8a master -> master (forced update)
 * [new branch]      docker-config-paas -> docker-config-paas
 * [new branch]      docker-config-prod -> docker-config-prod
 * [new branch]      docker-config-qa -> docker-config-qa
 * [new branch]      docker-config-staging -> docker-config-staging
 * [new branch]      docker-config-xz -> docker-config-xz

3.此时查看git bash没有报错，说明镜像推送成功了！去新的gitlab上查看

看看分支、分支的历史提交都在！！！

说明仓库同步完成！

如果后续要更新镜像，推送最新的变更到新仓库可以使用：

如需更新镜像，把源仓库最近的更新，再次同步到新仓库，那么你需要进入你的历史镜像目录，执行：

git remote update

目前还没测试再次同步的有效性！！！

2021年4月9日17:57:05 今天来试试，旧仓库有新的分支创建，叫paas-xizang，需要把这个改动同步到新仓库！

第一步，进入到以前执行git clone --mirror生成的镜像仓库目录

第二步，在此目录打开git bash,执行：git remote -v         

确认一下你的镜像仓库的拉取地址和推送地址的正确性

$ git remote -v
origin  http://10.251.9.191/open-v/section9-api.git (fetch)
origin  https://code.avlyun.org/victory/section9/be.git (push)

 拉取地址就是旧仓库的地址（当旧仓库有更新时，执行git remote update会去拉取旧仓库的变动）;

推送地址就是指这个镜像仓库最终数据同步到哪里！在此，当然是我们的新仓库地址。

第三步，执行：git remote update  

$ git remote update
Fetching origin

看到效果没，新增了new branch，顺带看看目录下的文件的时间戳是不是也更改了：

 说明，git remote update生效了，把旧仓库的新改动更新到了镜像仓库文件！

第四步，推送变动到新仓库

$ git push --mirror https://code.avlyun.org/victory/section9/be.git
Counting objects: 11, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (9/9), done.
Writing objects: 100% (11/11), 5.18 KiB | 2.59 MiB/s, done.
Total 11 (delta 9), reused 3 (delta 2)
remote:
remote: To create a merge request for paas-longyan, visit:
remote:   https://code.avlyun.org/victory/section9/be/-/merge_requests/new?merge                                                                                                                                                                                               _request%5Bsource_branch%5D=paas-longyan
remote:
remote:
remote: To create a merge request for paas-xizang, visit:
remote:   https://code.avlyun.org/victory/section9/be/-/merge_requests/new?merge                                                                                                                                                                                               _request%5Bsource_branch%5D=paas-xizang
remote:
To https://code.avlyun.org/victory/section9/be.git
 - [deleted]           longyan-paas
 * [new branch]        paas-longyan -> paas-longyan
 * [new branch]        paas-xizang -> paas-xizang

注意：这里的push是增量push，句式旧仓库有变动的地方才会同步到新仓库。不是无脑覆盖！！！

关于采坑说明：（只要建立目标仓库时，不要初始化就可以避免这些问题；建立个空仓库来放同步过来的内容，就没得问题）

1.注意新的gitlab的目标服务器如果不是空仓库，包含一个README的受保护的master分支的话，在推送前，需要在gitlab上面把受保护的取消掉

 否则无法推送成功！

2.这个源仓库（执行clone命令的目标仓库）没有master分支，且默认分支不叫master；但是新仓库地址的新建时，执行了init，有默认的master受保护仓库，推送时导致无法推送是因为默认分支不匹配！

在源仓库地址基于受保护的分支新建master分支，然后新仓库把master的受保护取消掉！在推送即可！

否则，报错如下：

wzp@DESKTOP-8HFQM2M MINGW64 /e/临时导出/s9-migrate/section9-config.git (BARE:doc                                                                                                                                                                                               ker-config-prod)
 
$ git push --mirror https://code.avlyun.org/victory/section9/config.git
 
Counting objects: 1221, done.
 
Delta compression using up to 8 threads.
 
Compressing objects: 100% (488/488), done.
 
Writing objects: 100% (1221/1221), 866.71 KiB | 86.67 MiB/s, done.
 
Total 1221 (delta 694), reused 1221 (delta 694)
 
remote: Resolving deltas: 100% (694/694), done.
 
remote: GitLab: The default branch of a project cannot be deleted.
 
To https://code.avlyun.org/victory/section9/config.git
 
 ! [remote rejected] master (pre-receive hook declined)
 
 ! [remote rejected] docker-config-paas -> docker-config-paas (pre-receive hook                                                                                                                                                                                                declined)
 
 ! [remote rejected] docker-config-prod -> docker-config-prod (pre-receive hook                                                                                                                                                                                                declined)
 
 ! [remote rejected] docker-config-qa -> docker-config-qa (pre-receive hook decl                                                                                                                                                                                               ined)
 
 ! [remote rejected] docker-config-staging -> docker-config-staging (pre-receive                                                                                                                                                                                                hook declined)
 
 ! [remote rejected] docker-config-xz -> docker-config-xz (pre-receive hook decl                                                                                                                                                                                               ined)
 
error: failed to push some refs to 'https://code.avlyun.org/victory/section9/con                                                                                                                                                                                               fig.git'

参考文档：

https://www.jianshu.com/p/076e389ea025

https://stackoverflow.com/questions/3959924/whats-the-difference-between-git-clone-mirror-and-git-clone-bare

https://qastack.cn/programming/6150188/how-to-update-a-git-clone-mirror