Azure DevOps Pipeline - Checkout only folder [duplicate] - azure-devops

Question

My repository in my organisation's devops project contains a lot of .net solutions and some unity projects as well. When I run my build pipeline, it fails due to several of these:
Error MSB3491: Could not write lines to file "obj\Release\path\to\file". There is not enough space on the disk.
I would like the pipeline to only checkout and fetch parts of the repository that are required for a successful build. This might also help with execution time of the pipeline since it currently also fetches the whole of my unity projects with gigabytes of resources which takes forever.
I would like to spread my projects across multiple repositories but the admin won't give me more than the one I already have. It got a lot better when I configured git fetch as shallow (--depth=1) but I still get the error every now and then.
This is how I configured the checkout:
steps:
- checkout: self
clean: true
# shallow fetch
fetchDepth: 1
lfs: false
submodules: false
The build is done using VSBuild#1 task.
I can't find a valid solution to my problem except for using multiple repositories, which is not an option right now.
Edit: Shayki Abramczyk's solution #1 works perfectly. Here is my full implementation.
GitSparseCheckout.yml:
parameters:
access: ''
repository: ''
sourcePath: ''
steps:
- checkout: none
- task: CmdLine#2
inputs:
script: |
ECHO ##[command] git init
git init
ECHO ##[command] git sparse-checkout: ${{ parameters.sourcePath }}
git config core.sparsecheckout true
echo ${{ parameters.sourcePath }} >> .git/info/sparse-checkout
ECHO ##[command] git remote add origin https://${{ parameters.repository }}
git remote add origin https://${{ parameters.access }}#${{ parameters.repository }}
ECHO ##[command] git fetch --progress --verbose --depth=1 origin master
git fetch --progress --verbose --depth=1 origin master
ECHO ##[command] git pull --progress --verbose origin master
git pull --progress --verbose origin master
Checkout is called like this (where template path has to be adjusted):
- template: ../steps/GitSparseCheckout.yml
parameters:
access: anything:<YOUR_PERSONAL_ACCESS_TOKEN>
repository: dev.azure.com/organisation/project/_git/repository
sourcePath: path/to/files/

Answer 1

In Azure DevOps you don't have option to get only part of the repository, but there is a workaround:
Disable the "Get sources" step and get only the source you want by manually executing the according git commands in a script.
To disable the default "Get Sources" just specify none in the checkout statement:
- checkout: none
In the pipeline add a CMD/PowerShell task to get the sources manually with one of the following 2 options:
1. Get only part of the repo with git sparse-checkout.
For example, get only the directories src_1 and src_2 within the test folder (lines starting with REM ### are just the usual batch comments):
- script: |
REM ### this will create a 'root' directory for your repo and cd into it
mkdir myRepo
cd myRepo
REM ### initialize Git in the current directory
git init
REM ### set Git sparsecheckout to TRUE
git config core.sparsecheckout true
REM ### write the directories that you want to pull to the .git/info/sparse-checkout file (without the root directory)
REM ### you can add multiple directories with multiple lines
echo test/src_1/ >> .git/info/sparse-checkout
echo test/src_2/ >> .git/info/sparse-checkout
REM ### fetch the remote repo using your access token
git remote add -f origin https://your.access.token#path.to.your/repo
REM ### pull the files from the source branch of this build, using the build-in Azure DevOps variable for the branch name
git pull origin $(Build.SourceBranch)
displayName: 'Get only test/src_1 & test/src_2 directories instead of entire repository'
Now in the builds task make myRepo the working directory.
Fetching the remote repo using an access token is necessary, since using checkout: none will prevent your login credentials from being used.
In the end of the pipeline you may want to add step to clean the myRepo directory.
2. Get parts of the repo with Azure DevOps Rest API (Git - Items - Get Items Batch).

Answer 2

The other answers work well but I found a different way using potentially newer features of git.
This will fetch to a depth of 1 and show all the files in the root folder plus folder1, folder2 and folder3
- task: CmdLine#2
inputs:
script: |
git init
git sparse-checkout init --cone
git sparse-checkout set folder1 folder2 folder3
git remote add origin https://<github-username>:%GITHUB_TOKEN%#<your-git-repo>
git fetch --progress --verbose --depth=1 origin
git switch develop
env:
GITHUB_TOKEN: $(GITHUB_TOKEN)

Answer 3

Maybe it is helpful for you to check out only a specific branch. This works by:
resources:
repositories:
- repository: MyGitHubRepo
type: github
endpoint: MyGitHubServiceConnection
name: MyGitHubOrgOrUser/MyGitHubRepo
ref: features/tools
steps:
- checkout: MyGitHubRepo
Or by using the inline syntax like so
- checkout: git://MyProject/MyRepo#features/tools # checks out the features/tools branch
- checkout: git://MyProject/MyRepo#refs/heads/features/tools # also checks out the features/tools branch
- checkout: git://MyProject/MyRepo#refs/tags/MyTag # checks out the commit referenced by MyTag.
More information can be found here

Answer 4

A Solution For Pull Request and Master Support
I realized after posting this solution it is similar to the updated one on the post. However this solution is a bit more rich and optimized. But most importantly this solution uses the pull request merge branch in Dev Ops for the deployments like the native checkouts do. It also fetches only the needed commits.
Supports multiple folder/path patterns as parameters
Minimal checkout with the bare minimum needed via sparse checkout
Shallow depth, multithreaded fetch, with a sparse index.
It takes into account using the PR merge branch against main rather than the raw PR branch itself if needed.
Uses native System Token already in pipeline
Handles detection and alternative ref flows for master where a merge branch does not exist.
Example Use in your Script:
- job: JobNameHere
displayName: JobDisplayName Here
steps:
- template: templates/sparse-checkout.yml
parameters:
checkoutFolders:
- /Scripts
- /example-file.ps1
# other steps
templates/sparse-checkout.yaml
parameters:
- name: checkoutFolders
default: '*'
type: object
steps:
- checkout: none
- task: PowerShell#2
inputs:
targetType: inline
script: |
$useMasterMergeIfAvaiable = $true
$checkoutFolders = ($env:CheckoutFolders | ConvertFrom-Json)
Write-Host $checkoutFolders
$sw = [Diagnostics.Stopwatch]::StartNew() # For timing the run.
$checkoutLocation = $env:Repository_Path
################ Setup Variables ###############
$accessToken = "$env:System_AccessToken";
$repoUriSegments = $env:Build_Repository_Uri.Split("#");
$repository = "$($repoUriSegments[0]):$accessToken#$($repoUriSegments[1])"
$checkoutBranchName = $env:Build_SourceBranch;
$prId = $env:System_PullRequest_PullRequestId;
$repositoryPathForDisplay = $repository.Replace("$accessToken", "****");
$isPullRequest = $env:Build_Reason -eq "PullRequest";
################ Configure Refs ##############
if ($isPullRequest)
{
Write-Host "Detected Pull Request"
$pullRequestRefMap = "refs/heads/$($checkoutBranchName):refs/remotes/origin/pull/$prId"
$mergeRefMap = "refs/pull/$prId/merge:refs/remotes/origin/pull/$prId";
$mergeRefRemote = $mergeRefMap.Split(":")[0];
$remoteMergeBranch = git ls-remote $repository "$mergeRefRemote" # See if remote merge ref exiss for PR.
if ($useMasterMergeIfAvaiable -and $remoteMergeBranch)
{
Write-Host "Remote Merge Branch Found: $remoteMergeBranch" -ForegroundColor Green
$refMapForCheckout = $mergeRefMap
$remoteRefForCheckout = "pull/$prId/merge"
}else{
Write-Host "No merge from master found (or merge flag is off in script), using pullrequest branch." -ForegroundColor Yellow
$refMapForCheckout = $pullRequestRefMap
$remoteRefForCheckout = "heads/$checkoutBranchName"
}
$localRef = "origin/pull/$prId"
}else{
Write-Host "This is not a pull request. Assuming master branch as source."
$localRef = "origin/master"
$remoteRefForCheckout = "master"
}
######## Sparse Checkout ###########
Write-Host "Beginning Sparse Checkout..." -ForegroundColor Green;
Write-Host " | Repository: $repositoryPathForDisplay" -ForegroundColor Cyan
if (-not (test-path $checkoutLocation) ) {
$out = mkdir -Force $checkoutLocation
}
$out = Set-Location $checkoutLocation
git init -q
git config core.sparsecheckout true
git config advice.detachedHead false
git config index.sparse true
git remote add origin $repository
git config remote.origin.fetch $refMapForCheckout
git sparse-checkout set --sparse-index $checkoutFolders
Write-Host " | Remote origin configured. Fetching..."
git fetch -j 4 --depth 1 --no-tags -q origin $remoteRefForCheckout
Write-Host " | Checking out..."
git checkout $localRef -q
Get-ChildItem -Name
# tree . # Shows a graphical structure - can be large with lots of files.
############ Clean up ##################
if (Test-Path -Path ..\$checkoutLocation)
{
Write-Host "`nChecked Out`n#############"
Set-Location ../
}
$sw.Stop()
Write-Host "`nCheckout Complete in $($sw.Elapsed.TotalSeconds) seconds." -ForegroundColor Green
displayName: 'Sparse Checkout'
env:
Build_Repository_Uri: $(Build.Repository.Uri)
Build_Reason: $(Build.Reason)
System_PullRequest_SourceBranch: $(System.PullRequest.SourceBranch)
System_PullRequest_PullRequestId: $(System.PullRequest.PullRequestId)
System_PullRequest_SourceRepositoryURI: $(System.PullRequest.SourceRepositoryURI)
Build_BuildId: $(Build.BuildId)
Build_SourceBranch: $(Build.SourceBranch)
CheckoutFolders: ${{ convertToJson(parameters.checkoutFolders) }}
System_AccessToken: $(System.AccessToken)
Repository_Path: $(Build.Repository.LocalPath)

Answer 5

With LFS support on Ubuntu and Windows agents
parameters:
folders: '*'
steps:
- bash: |
set -ex
export ORIGIN=$(Build.Repository.Uri)
export REF=$(Build.SourceVersion)
export FOLDERS='${{ parameters.folders }}'
git version
git lfs version
git init
git sparse-checkout init --cone
git sparse-checkout add $FOLDERS
git remote add origin $ORIGIN
git config core.sparsecheckout true
git config gc.auto 0
git config advice.detachedHead false
git config http.version HTTP/1.1
git lfs install --local
git config uploadpack.allowReachableSHA1InWant true
git config http.extraheader "AUTHORIZATION: bearer $(System.AccessToken)"
git fetch --force --no-tags --progress --depth 1 origin develop $REF
git checkout $REF --progress --force
displayName: Fast sparse Checkout
Then use as a step
steps:
- checkout: none
- template: fastCheckout.yaml
parameters:
folders: 'Folder1 src/Folder2'
You can pass folders as paramters
The exports are there to make it easier to test the script locally.
Improved checkouts from 10mins to 2mins