如何克隆仅Git存储库的子目录？

git clone --filter 来自Git 2.19

该选项实际上将跳过从服务器获取不需要的对象:

git clone \
  --depth 1 \
  --filter=blob:none \
  --filter=tree:0 \
  --no-checkout \
  "file://$(pwd)/server_repo" \
  local_repo \
;
cd local_repo
git checkout master -- mydir/

服务器应配置为:

git config --local uploadpack.allowfilter 1
git config --local uploadpack.allowanysha1inwant 1

扩展了Git远程协议以支持v2.19.0中的此功能,但当时没有服务器支持.但它已经可以在本地测试了.

TODO:--filter=tree:0跳过所有blob,但仍然获取所有树对象.但是在正常的回购中,与文件本身相比,这应该很小,所以这已经足够了.询问:https: //www.spinics.net/lists/git/msg342006.html Devs回复了一个v2.19.0正在开展的工作.

请记住,--filter=blob:none已经暗示--filter=tree:0,另请参阅:如何在Git中克隆单个分支？

--depth 1需要克服--single-branch协议恶作剧:如何使用相对路径浅层克隆本地git存储库？

格式file://$(path)记录在上面git clone.

Git树上的文档:

https://github.com/git/git/blob/v2.19.0/Documentation/technical/partial-clone.txt

https://github.com/git/git/blob/v2.19.0/Documentation/rev-list-options.txt#L720

https://github.com/git/git/blob/v2.19.0/t/t5616-partial-clone.sh

测试一下

#!/usr/bin/env bash
set -eu

list-objects() (
  git rev-list --all --objects
  echo "master commit SHA: $(git log -1 --format="%H")"
  echo "mybranch commit SHA: $(git log -1 --format="%H")"
  git ls-tree master
  git ls-tree mybranch | grep mybranch
  git ls-tree master~ | grep root
)

# Reproducibility.
export GIT_COMMITTER_NAME='a'
export GIT_COMMITTER_EMAIL='a'
export GIT_AUTHOR_NAME='a'
export GIT_AUTHOR_EMAIL='a'
export GIT_COMMITTER_DATE='2000-01-01T00:00:00+0000'
export GIT_AUTHOR_DATE='2000-01-01T00:00:00+0000'

rm -rf server_repo local_repo
mkdir server_repo
cd server_repo

# Create repo.
git init --quiet
git config --local uploadpack.allowfilter 1
git config --local uploadpack.allowanysha1inwant 1

# First commit.
# Directories present in all branches.
mkdir d1 d2
printf 'd1/a' > ./d1/a
printf 'd1/b' > ./d1/b
printf 'd2/a' > ./d2/a
printf 'd2/b' > ./d2/b
# Present only in root.
mkdir 'root'
printf 'root' > ./root/root
git add .
git commit -m 'root' --quiet

# Second commit only on master.
git rm --quiet -r ./root
mkdir 'master'
printf 'master' > ./master/master
git add .
git commit -m 'master commit' --quiet

# Second commit only on mybranch.
git checkout -b mybranch --quiet master~
git rm --quiet -r ./root
mkdir 'mybranch'
printf 'mybranch' > ./mybranch/mybranch
git add .
git commit -m 'mybranch commit' --quiet

echo "# List and identify all objects"
list-objects
echo

# Restore master.
git checkout --quiet master
cd ..

# Clone. Don't checkout for now, only .git/ dir.
git clone --depth 1 --quiet --no-checkout --filter=blob:none "file://$(pwd)/server_repo" local_repo
cd local_repo

# List missing objects from master.
echo "# Missing objects after --no-checkout"
git rev-list --all --quiet --objects --missing=print
echo

echo "# Git checkout fails without internet"
mv ../server_repo ../server_repo.off
! git checkout master
echo

echo "# Git checkout fetches the missing directory from internet"
mv ../server_repo.off ../server_repo
git checkout master -- d1/
echo

echo "# Missing objects after checking out d1"
git rev-list --all --quiet --objects --missing=print

GitHub上游.

Git v2.19.0中的输出:

# List and identify all objects
c6fcdfaf2b1462f809aecdad83a186eeec00f9c1
fc5e97944480982cfc180a6d6634699921ee63ec
7251a83be9a03161acde7b71a8fda9be19f47128
62d67bce3c672fe2b9065f372726a11e57bade7e
b64bf435a3e54c5208a1b70b7bcb0fc627463a75 d1
308150e8fddde043f3dbbb8573abb6af1df96e63 d1/a
f70a17f51b7b30fec48a32e4f19ac15e261fd1a4 d1/b
84de03c312dc741d0f2a66df7b2f168d823e122a d2
0975df9b39e23c15f63db194df7f45c76528bccb d2/a
41484c13520fcbb6e7243a26fdb1fc9405c08520 d2/b
7d5230379e4652f1b1da7ed1e78e0b8253e03ba3 master
8b25206ff90e9432f6f1a8600f87a7bd695a24af master/master
ef29f15c9a7c5417944cc09711b6a9ee51b01d89
19f7a4ca4a038aff89d803f017f76d2b66063043 mybranch
1b671b190e293aa091239b8b5e8c149411d00523 mybranch/mybranch
c3760bb1a0ece87cdbaf9a563c77a45e30a4e30e
a0234da53ec608b54813b4271fbf00ba5318b99f root
93ca1422a8da0a9effc465eccbcb17e23015542d root/root
master commit SHA: fc5e97944480982cfc180a6d6634699921ee63ec
mybranch commit SHA: fc5e97944480982cfc180a6d6634699921ee63ec
040000 tree b64bf435a3e54c5208a1b70b7bcb0fc627463a75    d1
040000 tree 84de03c312dc741d0f2a66df7b2f168d823e122a    d2
040000 tree 7d5230379e4652f1b1da7ed1e78e0b8253e03ba3    master
040000 tree 19f7a4ca4a038aff89d803f017f76d2b66063043    mybranch
040000 tree a0234da53ec608b54813b4271fbf00ba5318b99f    root

# Missing objects after --no-checkout
?f70a17f51b7b30fec48a32e4f19ac15e261fd1a4
?8b25206ff90e9432f6f1a8600f87a7bd695a24af
?41484c13520fcbb6e7243a26fdb1fc9405c08520
?0975df9b39e23c15f63db194df7f45c76528bccb
?308150e8fddde043f3dbbb8573abb6af1df96e63

# Git checkout fails without internet
fatal: '/home/ciro/bak/git/test-git-web-interface/other-test-repos/partial-clone.tmp/server_repo' does not appear to be a git repository
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

# Git checkout fetches the missing directory from internet
remote: Enumerating objects: 1, done.
remote: Counting objects: 100% (1/1), done.
remote: Total 1 (delta 0), reused 0 (delta 0)
Receiving objects: 100% (1/1), 45 bytes | 45.00 KiB/s, done.
remote: Enumerating objects: 1, done.
remote: Counting objects: 100% (1/1), done.
remote: Total 1 (delta 0), reused 0 (delta 0)
Receiving objects: 100% (1/1), 45 bytes | 45.00 KiB/s, done.

# Missing objects after checking out d1
?8b25206ff90e9432f6f1a8600f87a7bd695a24af
?41484c13520fcbb6e7243a26fdb1fc9405c08520
?0975df9b39e23c15f63db194df7f45c76528bccb

结论:所有来自外部的斑点--filter都缺失了.例如man git-rev-list,d1/退房后不存在0975df9b39e23c15f63db194df7f45c76528bccb.

需要注意的是d2/b和d1/a也丢失,但root/root隐藏了从丢失文件的列表.如果删除mybranch/mybranch,则它们会显示在丢失文件列表中.

我有一个梦想

这个功能可以彻底改变Git.

想象一下,在没有丑陋的第三方工具的--depth 1情况下,将企业的所有代码库都放在一个仓库中.

想象一下,在没有任何丑陋的第三方扩展的情况下,直接在回购中存储巨大的blob.

想象一下,如果GitHub允许每个文件/目录元数据(如星标和权限),那么您可以将所有个人资料存储在一个回购中.

想象一下,如果子模块的处理方式与常规目录完全相同:只需要一个树SHA,并且类似DNS的机制可以解析您的请求,首先查看您的本地--depth 1,然后是第一个更近的服务器(您企业的镜像/缓存),最后是GitHub.

对于只想从github 下载文件/文件夹的其他用户,只需使用:

svn export /trunk/

例如

svn export https://github.com/lodash/lodash.com/trunk/docs

(是的,这是svn在这里.显然在2016年你仍然需要svn来简单地下载一些github文件)

礼貌:从GitHub仓库下载单个文件夹或目录

重要 - 确保更新github URL并替换/tree/master/为'/ trunk /'.

作为bash脚本:

git-download(){
    folder=${@/tree\/master/trunk}
    folder=${folder/blob\/master/trunk}
    svn export $folder
}

注意 此方法下载文件夹,不克隆/签出它.您无法将更改推送回存储库.另一方面 - 与稀疏结账或浅结账相比,这导致更小的下载.

如果您从未计划与克隆的存储库进行交互,则可以使用git filter-branch --subdirectory-filter执行完整的git克隆并重写您的存储库.这样,至少会保留历史记录.

Git 1.7.0有"稀疏结账".请参阅git config联机帮助页中的"core.sparseCheckout",git read-tree联机帮助页中的"Sparse checkout" 和git update-index联机帮助页中的"Skip-worktree bit" .

接口不如SVN那么方便(例如,在初始克隆时无法进行稀疏检出),但现在可以使用可以构建更简单接口的基本功能.

这看起来简单得多:

git archive --remote=   | tar xvf -

仅使用Git克隆子目录是不可能的,但下面是几个解决方法.

过滤分支

您可能希望重写存储库以使其看起来像是trunk/public_html/项目的根目录,并丢弃所有其他历史记录(使用filter-branch),尝试已经结帐的分支:

git filter-branch --subdirectory-filter trunk/public_html -- --all

^{注意:--将过滤器分支选项与修订选项分开,并--all重写所有分支和标记.将保留包括原始提交时间或合并信息在内的所有信息.此命令.git/info/grafts用于表示refs/replace/命名空间中的文件和引用,因此如果您refs定义了任何移植或替换,则运行此命令将使它们成为永久性的.}

警告!重写的历史将具有所有对象的不同对象名称,并且不会与原始分支会聚.您将无法在原始分支的顶部轻松推送和分发重写的分支.如果您不知道完整的含义,请不要使用此命令,并且无论如何都要避免使用它,如果简单的单个提交就足以解决您的问题.

稀疏结账

以下是使用稀疏检出方法的简单步骤,它将稀疏地填充工作目录,因此您可以告诉Git工作目录中的哪个文件夹或文件值得检出.

像往常一样克隆存储库(--no-checkout是可选的):

git clone --no-checkout git@foo/bar.git
cd bar

^{如果已经克隆了存储库,则可以跳过此步骤.}

提示:对于大型回购,请考虑浅层克隆(--depth 1)仅签出最新修订版或/和--single-branch仅.

启用sparseCheckout选项:

git config core.sparseCheckout true

指定稀疏结帐的文件夹(末尾没有空格):

echo "trunk/public_html/*"> .git/info/sparse-checkout

或编辑.git/info/sparse-checkout.

签出分支(例如master):

git checkout master

现在您应该在当前目录中选择了文件夹.

如果您有太多级别的目录或过滤分支,您可以考虑使用符号链接.

我刚为GitHub 写了一个脚本.

用法:

python get_git_sub_dir.py path/to/sub/dir 

这将克隆一个特定的文件夹，并删除所有与此文件夹不相关的历史记录。

git clone --single-branch -b {branch} git@github.com:{user}/{repo}.git
git filter-branch --subdirectory-filter {path/to/folder} HEAD
git remote remove origin
git remote add origin git@github.com:{user}/{new-repo}.git
git push -u origin master

这是我为单个子目录稀疏结账的用例编写的shell脚本

coSubDir.sh

localRepo=$1
remoteRepo=$2
subDir=$3


# Create local repository for subdirectory checkout, make it hidden to avoid having to drill down to the subfolder
mkdir ./.$localRepo
cd ./.$localRepo
git init
git remote add -f origin $remoteRepo
git config core.sparseCheckout true

# Add the subdirectory of interest to the sparse checkout.
echo $subDir >> .git/info/sparse-checkout

git pull origin master

# Create convenience symlink to the subdirectory of interest
cd ..
ln -s ./.$localRepo/$subDir $localRepo