【Git】尝试验证git子模块的行为【杂记】
为了确认子模块的行为，逐个执行命令并确认其行为。
注册子模块
> git submodule add git@github.com:kiyo27/git-submodule.git
确认更改。.gitmodules已创建。
> git status
On branch main
Your branch is up to date with 'origin/main'.
Changes to be committed:
(use "git restore --staged <file>..." to unstage)
new file: .gitmodules
new file: git-submodule
> git diff HEAD git-submodule
diff --git a/git-submodule b/git-submodule
new file mode 160000
index 0000000..94a3033
--- /dev/null
+++ b/git-submodule
@@ -0,0 +1 @@
+Subproject commit 94a3033e4124495a4f6c44d373b02f14c24cf213
提交更改
> git add .gitmodules
> git add git-submodule
> git commit -m "update submodule to new version"
> git push origin main
提交指针已注册。
更新子模块
子项目更新
// git-submodule(submoduleのリポジトリ)
> touch version.txt
> echo "version 1" > version.txt
> git add version.txt
> git commit -m "add version file"
> git push origin main
在包含子模块的项目中，将子模块的更新合并进来。
> cd git-submodule
> git fetch
remote: Enumerating objects: 4, done.
remote: Counting objects: 100% (4/4), done.
remote: Compressing objects: 100% (2/2), done.
remote: Total 3 (delta 0), reused 3 (delta 0), pack-reused 0
Unpacking objects: 100% (3/3), 287 bytes | 16.00 KiB/s, done.
From github.com:kiyo27/git-submodule
94a3033..388a533 main -> origin/main
> git merge origin/main
Updating 94a3033..388a533
Fast-forward
version.txt | 1 +
1 file changed, 1 insertion(+)
create mode 100644 version.txt
> ls
README.md version.txt
更新git子模块
我手动进行了合并，但使用git submodule update –remote可以自动完成。
> git submodule update --remote
remote: Enumerating objects: 5, done.
remote: Counting objects: 100% (5/5), done.
remote: Compressing objects: 100% (2/2), done.
remote: Total 3 (delta 0), reused 3 (delta 0), pack-reused 0
Unpacking objects: 100% (3/3), 279 bytes | 16.00 KiB/s, done.
From github.com:kiyo27/git-submodule
49324e5..d1d4ad0 main -> origin/main
Submodule path 'git-submodule': checked out 'd1d4ad0f0223cb676f6b71b6c4fafe0be83520c6'
检出分支（使HEAD进入分离状态）。
分离的 HEAD 的状态
> git status
HEAD detached at d1d4ad0
nothing to commit, working tree clean
> git branch
* (HEAD detached at d1d4ad0)
main
在 `detached HEAD` 状态下，即使对子模块进行更改，执行 `git submodule update` 命令后，更改的内容也会消失。
修改子模块
ver 7
file change in sub project.
提交更改
> git commit -am "update"
在主项目中运行git submodule update
> git submodule update --remote
Submodule path 'git-submodule': checked out 'd1d4ad0f0223cb676f6b71b6c4fafe0be83520c6'
当检查在子模块中进行更改的文件时，发现更改的内容已经消失。
> cd git-submodule
> cat version.txt
ver 7
更新并合并远程的 git submodule。
通过执行命令 “git submodule update –remote –merge” 来合并分支。
> git submodule update --remote --merge
remote: Enumerating objects: 8, done.
remote: Counting objects: 100% (8/8), done.
remote: Compressing objects: 100% (2/2), done.
remote: Total 4 (delta 1), reused 4 (delta 1), pack-reused 0
Unpacking objects: 100% (4/4), 496 bytes | 29.00 KiB/s, done.
From github.com:kiyo27/git-submodule
351be29..a2913d2 main -> origin/main
Updating 351be29..a2913d2
Fast-forward
Submodule path 'git-submodule': merged in 'a2913d257fe9442460eeae93d61ca2078212ef90'
分支状态不是分离的HEAD。
> git branch
* main
在主要项目中更新子模块。
修改子模块的内容
> cd git-submodule
> echo "version @" > version.txt
> git commit -am "update"
我会尝试在主要项目中将报告推送出去，然后进行差异确认。
> git status
On branch main
Your branch is up to date with 'origin/main'.
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: git-submodule (new commits)
no changes added to commit (use "git add" and/or "git commit -a")
提交更改并将其推送到远程。
> git add git-submodule
> git commit -m "update submodule"
> git push origin main
Enumerating objects: 3, done.
Counting objects: 100% (3/3), done.
Delta compression using up to 8 threads
Compressing objects: 100% (2/2), done.
Writing objects: 100% (2/2), 268 bytes | 268.00 KiB/s, done.
Total 2 (delta 1), reused 0 (delta 0), pack-reused 0
remote: Resolving deltas: 100% (1/1), completed with 1 local object.
To github.com:kiyo27/git-practice.git
0c89257..a150914 main -> main
如果不推送子模块的更改，而是提交和推送主项目，其他人将无法获取到子模块的更改。主项目的子模块指向了已更改的指针。
通过添加 “–recurse-submodules=check” 参数，可以检查子模块的变更是否已经推送，如果子模块未推送，则不允许推送主项目。
> git push --recurse-submodules=check
The following submodule paths contain changes that can
not be found on any remote:
git-submodule
Please try
git push --recurse-submodules=on-demand
or cd to the path and use
git push
to push them to a remote.
fatal: Aborting.
通过添加–recurse-submodules=on-demand来在主项目push时也将子模块一并push。
> git push --recurse-submodules=on-demand
Pushing submodule 'git-submodule'
Enumerating objects: 5, done.
Counting objects: 100% (5/5), done.
Delta compression using up to 8 threads
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 291 bytes | 291.00 KiB/s, done.
Total 3 (delta 1), reused 0 (delta 0), pack-reused 0
remote: Resolving deltas: 100% (1/1), completed with 1 local object.
To github.com:kiyo27/git-submodule.git
3822fdd..351be29 main -> main
Enumerating objects: 3, done.
Counting objects: 100% (3/3), done.
Delta compression using up to 8 threads
Compressing objects: 100% (2/2), done.
Writing objects: 100% (2/2), 261 bytes | 261.00 KiB/s, done.
Total 2 (delta 1), reused 0 (delta 0), pack-reused 0
remote: Resolving deltas: 100% (1/1), completed with 1 local object.
To github.com:kiyo27/git-practice.git
72055b4..0c89257 main -> main
或者，您可以在子模块上进行作业并进行推送。
> cd git-submodule
> git push origin main
克隆含有子模块的项目
克隆包含子模块的项目。但仅仅克隆项目并不能获取子模块的内容，它们是空的。
> git clone git@github.com:kiyo27/git-practice.git main-project
> ls -la
total 0
drwxrwxrwx 1 ubuntu ubuntu 4096 Jul 18 12:20 .
drwxrwxrwx 1 ubuntu ubuntu 4096 Jul 18 12:20 ..
执行 git submodule init 和 git submodule update
> git submodule init
Submodule 'git-submodule' (git@github.com:kiyo27/git-submodule.git) registered for path 'git-submodule'
> git submodule update
Cloning into 'C:/Users/narik/workspace/git/main-project/git-submodule'...
Submodule path 'git-submodule': checked out 'daf413635a93e7622c31d11d7313e042eee91ea5'
子模块的内容
> ls -la git-submodule
total 0
drwxrwxrwx 1 ubuntu ubuntu 4096 Jul 18 12:24 .
drwxrwxrwx 1 ubuntu ubuntu 4096 Jul 18 12:20 ..
-rwxrwxrwx 1 ubuntu ubuntu 38 Jul 18 12:24 .git
-rwxrwxrwx 1 ubuntu ubuntu 17 Jul 18 12:24 README.md
-rwxrwxrwx 1 ubuntu ubuntu 9 Jul 18 12:24 version.txt
该分支处于detached HEAD的状态。
> git branch
* (HEAD detached at daf4136)
main
当您克隆包含子模块的项目时，使用–recursive选项将帮助您同时进行子模块的初始化和数据获取。
> git clone --recursive git@github.com:kiyo27/git-practice.git main-project
Cloning into 'main-project'...
remote: Enumerating objects: 72, done.
remote: Counting objects: 100% (72/72), done.
remote: Compressing objects: 100% (49/49), done.
remote: Total 72 (delta 12), reused 66 (delta 6), pack-reused 0
Receiving objects: 100% (72/72), 8.20 KiB | 839.00 KiB/s, done.
Resolving deltas: 100% (12/12), done.
Submodule 'git-submodule' (git@github.com:kiyo27/git-submodule.git) registered for path 'git-submodule'
Cloning into 'C:/Users/narik/workspace/git/main-project/git-submodule'...
remote: Enumerating objects: 42, done.
remote: Counting objects: 100% (42/42), done.
remote: Compressing objects: 100% (27/27), done.
remote: Total 42 (delta 2), reused 40 (delta 0), pack-reused 0
Receiving objects: 100% (42/42), done.
Resolving deltas: 100% (2/2), done.
Submodule path 'git-submodule': checked out 'daf413635a93e7622c31d11d7313e042eee91ea5'
子模块的内容。数据已经获取到了。
> ls -la git-submodule/
total 0
drwxrwxrwx 1 ubuntu ubuntu 4096 Jul 18 12:29 .
drwxrwxrwx 1 ubuntu ubuntu 4096 Jul 18 12:29 ..
-rwxrwxrwx 1 ubuntu ubuntu 38 Jul 18 12:29 .git
-rwxrwxrwx 1 ubuntu ubuntu 17 Jul 18 12:29 README.md
-rwxrwxrwx 1 ubuntu ubuntu 9 Jul 18 12:29 version.txt
