本文以 skywalking-rocketbot-ui子模块合并到 skywalking 为例，手把手教你如何把 Git 子模块更新到主项目中去。

首先，把fork的skywalking项目克隆到本地：

OneMore MINGW64 /d/code
$ git clone https://github.com/heihaozi/skywalking.git skywalking
Cloning into 'skywalking'...
remote: Enumerating objects: 241687, done.
remote: Counting objects: 100% (373/373), done.
remote: Compressing objects: 100% (201/201), done.
remote: Total 241687 (delta 64), reused 240 (delta 21), pack-reused 241314
Receiving objects: 100% (241687/241687), 156.98 MiB | 3.83 MiB/s, done.
Resolving deltas: 100% (93272/93272), done.
Updating files: 100% (5928/5928), done.

进入skywalking目录，设置用户名和邮箱：

OneMore MINGW64  /d/code
$ cd skywalking/

OneMore MINGW64  /d/code/skywalking (master)
$ git config user.name CharliePu

OneMore MINGW64  /d/code/skywalking (master)
$ git config user.email heihaozi2006@163.com

指定将与复刻同步的远程上游仓库：

OneMore MINGW64  /d/code/skywalking (master)
$ git remote add upstream https://github.com/apache/skywalking.git

查看一下远程上游仓库是否生效：

OneMore MINGW64  /d/code/skywalking (master)
$ git remote -v
origin  https://github.com/heihaozi/skywalking.git (fetch)
origin  https://github.com/heihaozi/skywalking.git (push)
upstream        https://github.com/apache/skywalking.git (fetch)
upstream        https://github.com/apache/skywalking.git (push)

没有问题，初始化本地子模块：

OneMore MINGW64  /d/code/skywalking (master)
$ git submodule init
Submodule 'apm-protocol/apm-network/src/main/proto' (https://github.com/apache/skywalking-data-collect-protocol.git) registered for path 'apm-protocol/apm-network/src/main/proto'
Submodule 'oap-server/server-query-plugin/query-graphql-plugin/src/main/resources/query-protocol' (https://github.com/apache/skywalking-query-protocol.git) registered for path 'oap-server/server-query-plugin/query-graphql-plugin/src/main/resources/query-protocol'
Submodule 'skywalking-ui' (https://github.com/apache/skywalking-rocketbot-ui.git) registered for path 'skywalking-ui'
Submodule 'test/e2e/e2e-protocol/src/main/proto' (https://github.com/apache/skywalking-data-collect-protocol.git) registered for path 'test/e2e/e2e-protocol/src/main/proto'

从子模块的远端更新修改：

OneMore MINGW64  /d/code/skywalking (master)
$ git submodule update
Cloning into 'D:/code/skywalking/apm-protocol/apm-network/src/main/proto'...
Cloning into 'D:/code/skywalking/oap-server/server-query-plugin/query-graphql-plugin/src/main/resources/query-protocol'...
Cloning into 'D:/code/skywalking/skywalking-ui'...
Cloning into 'D:/code/skywalking/test/e2e/e2e-protocol/src/main/proto'...
Submodule path 'apm-protocol/apm-network/src/main/proto': checked out 'e626ee04850703c220f64b642d2893fa65572943'
Submodule path 'oap-server/server-query-plugin/query-graphql-plugin/src/main/resources/query-protocol': checked out '47202fc1eaa1864c587a78f423a0685ffbe294ad'
Submodule path 'skywalking-ui': checked out '9e56d6cbbaff4678751f5355b953db3bbfd99c9b'
Submodule path 'test/e2e/e2e-protocol/src/main/proto': checked out 'e626ee04850703c220f64b642d2893fa65572943'

从子模块的远端拉取上游的修改：

OneMore MINGW64  /d/code/skywalking (master)
$ git submodule update --remote
Submodule path 'skywalking-ui': checked out '774b69dd84e305be975e4c5ffc0d433aa8cbda32'

检查当前文件状态：

OneMore MINGW64  /d/code/skywalking (master)
$ git status
On branch master
Your branch is up to date with 'origin/master'.

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   skywalking-ui (new commits)

no changes added to commit (use "git add" and/or "git commit -a")

发现skywalking-ui已经有更新了，可以直接将其提交到远端，也可以修改其他文件一起提交。

这里先修改一下CHANGES.md文件，然后一起提交：

OneMore MINGW64  /d/code/skywalking (master)
$ git add skywalking-ui

OneMore MINGW64  /d/code/skywalking (master)
$ git add CHANGES.md

OneMore MINGW64  /d/code/skywalking (master)
$ git status
On branch master
Your branch is up to date with 'origin/master'.

Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        modified:   CHANGES.md
        modified:   skywalking-ui


OneMore MINGW64  /d/code/skywalking (master)
$ git push origin master
Enumerating objects: 5, done.
Counting objects: 100% (5/5), done.
Delta compression using up to 8 threads
Compressing objects: 100% (3/3), done.
Writing objects: 100% (3/3), 409 bytes | 409.00 KiB/s, done.
Total 3 (delta 2), reused 0 (delta 0), pack-reused 0
remote: Resolving deltas: 100% (2/2), completed with 2 local objects.
To https://github.com/heihaozi/skywalking.git
   50688c187..e4a61f183  master -> master

至此，大功告成，可以向社区提交PR了。

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