Why are there Microsoft packages in my private Nuget Feed in DevOps Artifacts?

Question

Here is my build pipeline

# .NET Desktop
# Build and run tests for .NET Desktop or Windows classic desktop solutions.
# Add steps that publish symbols, save build artifacts, and more:
# https://learn.microsoft.com/azure/devops/pipelines/apps/windows/dot-net

trigger:
- master

pool:
  vmImage: 'VS2017-Win2016'

variables:
  solution: '**/*.sln'
  buildPlatform: 'Any CPU'
  buildConfiguration: 'Release'
  Major: '2'
  Minor: '0'
  Patch: '0'

steps:
- task: NuGetToolInstaller@0

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

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

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

- task: NuGetCommand@2
  inputs:
    command: pack
    packagesToPack: '**/*.csproj'
    versioningScheme: byPrereleaseNumber
    majorVersion: '$(Major)'
    minorVersion: '$(Minor)'
    patchVersion: '$(Patch)'

- task: NuGetCommand@2
  displayName: 'NuGet push'
  inputs:
    command: push
    publishVstsFeed: 'MyCommonFeed'
    allowPackageConflicts: true

I was surprised to see that the feed created contains packages from Nuget.org Why?

Answer 1

Why are there Microsoft packages in my private Nuget Feed in DevOps Artifacts?

That because your private Nuget Feed set nuget.org as an Upstream source by default if you set Package from public sources enable when you create the this feed:

Then go to Setting->Upstream source, you will find there are three public sources listed:

You could use the source filter to select the source of the package.

When we download any packages from the Upstream sources, it will been cached in the Artifacts, you will see it next time.

Hope this helps.