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Azure DevOps YAML build pipeline : Where is checkout?

kenakamu profile image Kenichiro Nakamura ・3 min read

I use Azure DevOps for long time, and I always use GUI when crafting Build Pipeline so far, though I knew Azure DevOps supports YAML and its benefits.

So this time, I tried YAML instead of GUI and I learnt many things. In this article, I talk about "checkout" task.

When I first created YAML pipeline, my first question was where is my source code checkout information inside YAML as I only saw trigger. I eventually figured out but I leave memo here.

GUI experience

The very first thing I see in GUI is "select a source", which includes:

  • Type of repository
  • Where is the repo
  • Which branch to checkout Alt Text

After that, I select template. This time, I select "empty job" as I build dotnet core console app.
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Then adding bunch of tasks as I needed.
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I see "Get sources" at the beginning which is the starting point.

YAML experience

Now let's see the YAML experience. I start by selecting repository type.
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Then select actual repository.
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Then select template.
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And this is the generated YAML.

# .NET Desktop
# Build and run tests for .NET Desktop or Windows classic desktop solutions.
# Add steps that publish symbols, save build artifacts, and more:

- master

  vmImage: 'windows-latest'

  solution: '**/*.sln'
  buildPlatform: 'Any CPU'
  buildConfiguration: 'Release'

- task: NuGetToolInstaller@1

- task: NuGetCommand@2
    restoreSolution: '$(solution)'

- task: VSBuild@1
    solution: '$(solution)'
    platform: '$(buildPlatform)'
    configuration: '$(buildConfiguration)'

- task: VSTest@2
    platform: '$(buildPlatform)'
    configuration: '$(buildConfiguration)'

So there are several things I didn't understand at the begining.

  • Where is "Get sources" or checkout task?
  • How to set branch as source?
  • Where did the repository information go?

Also that the YAML file is saved in either master or new branch. As I usually block direct commit to master branch, I created new branch.
Alt Text

Checkout mystery

First of all, I need to figure out the checkout stuff. By reading Check out multiple repositories in your pipeline, I understand it's omitted by default.

The following combinations of checkout steps are supported.
If there are no checkout steps, the default behavior is as if checkout: self were the first step.

When I run the pipeline as it is, I see checkout task as expected.
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The "self" is the branch it's triggered the pipeline. If I trigger it manually, I can select which branch to run it, then the self becomes the branch I selected.

Set branch

So I don't have to set which branch to checkout, but simply configure the trigger. Specify events that trigger pipeline builds and releases provides enough information to me.

The repository Info

There is a settings I can change to specify the repository. Click [...] for more menu and click "Trigger". (Not settings)
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There are several settings I can change. Go to YAML tab and I can change the repository.
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In this article, I only talk about "checkout" task, and I just need to know the concept and basics, then it's not that different from GUI version anyway.

There are many other things I learnt which I will make note later.

Discussion (2)

Editor guide
useric profile image
Iurie Caradja

Its probably not relevant at this point but since there are no answers, here is the documentation reference for this topic:

by default there is no need to do anything as it is handled by the pipeline, but if you want, you can specify your custom configuration for the git operations

edit: grammar

kenakamu profile image
Kenichiro Nakamura Author

Thanks for the info! Yeah, we don't need to specify it but I was a bit curious how "automagically" checkout happens :)