Git tag at the end of build on Visual Studio Onlin

Question

I'd like to automatically tag a commit when a build is successful on VSO build vNext. I've read the doc including this page https://msdn.microsoft.com/Library/vs/alm/Build/scripts/variables and I've setup a small PowerShell script. First of all, it seems that BUILD_REPOSITORY_AUTH_USERNAME variable (and its friend password) are empty. I guess they're only available with external gits ? Second of all, it seems that the checkout for build is done via tasks which runs LibGit2Sharp, therefore credentials are not stored in any helper.

This is my PowerShell script :

git tag $Env:BUILD_BUILDNUMBER
git status
git config -l 
git push --progress https://$Env:GITUSER:$Env:[e-mail]/DefaultCollection/_git/myproject tag $Env:BUILD_BUILDNUMBER
git status
exit

It works well on my machine but on the agent (hosted pool) but it seems to hang on the agent at the push command (after 1h, it got automatically killed by the controller).

Here are the log:

******************************************************************************
Starting task: Powershell: tools/GitCommands.ps1
******************************************************************************
HEAD detached at 819e778
nothing to commit, working directory clean
core.symlinks=false
core.autocrlf=true
color.diff=auto
color.status=auto
color.branch=auto
color.interactive=true
pack.packsizelimit=2g
help.format=html
http.sslcainfo=/bin/curl-ca-bundle.crt
sendemail.smtpserver=/bin/msmtp.exe
diff.astextplain.textconv=astextplain
rebase.autosquash=true
core.bare=false
core.filemode=false
core.symlinks=false
core.ignorecase=true
core.logallrefupdates=true
core.repositoryformatversion=0
remote.origin.url=https://myrepo.visualstudio.com/DefaultCollection/_git/myproject
remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
branch.master.remote=origin
branch.master.merge=refs/heads/master

******************************************************************************
Finishing task: PowerShell
******************************************************************************

As you can see, no log for the push nor the status command. Any idea on how to achieve this ?

Answer 1

To answer the question (or better the title of the question). Just let the vNext build do it.

As mentioned in the comments, this is not available for external git repositories.

Answer 2

I'm answering myself on what I was trying to do (git tag was one of the few tasks I wanted to do). It's now possible to execute git commands in scripts. The documentation is here : https://www.visualstudio.com/en-us/docs/build/scripts/git-commands

Here is the howto:

Enable scripts to run Git commands

Grant version control permissions to the build service:

• Go to the Version Control control panel tab ▼
• On the Version Control tab, select the repository in which you want to run Git commands, and then select Project Collection Build Service.
• Grant permissions needed for the Git commands you want to run.

Typically you'll want to grant:

• Branch creation: Allow
• Contribute: Allow
• Read: Inherited allow
• Tag creation: Inherited allow

When you're done granting the permissions, make sure to click Save changes.

Enable your build definition to run Git.exe

On the variables tab set this variable: system.prefergit to true

On the options tab select Allow scripts to access OAuth token.