Accessing Azure Artifacts from a docker container in a Pipelines build

azure-pipelines.cd.yaml

resources:
- repo: self
queue:
  name: Hosted Ubuntu 1604
variables:
- group: Artifacts

steps:
- task: Docker@1
  displayName: 'Build an image'
  inputs:
    azureSubscriptionEndpoint: 'DemoSPNConnection'
    azureContainerRegistry: demo.azurecr.io
    arguments: '--build-arg ARTIFACTS_ENDPOINT=$(artifactsEndpoint) --build-arg ACCESS_TOKEN=$(artifactsAccessToken)'

- task: Docker@1
  displayName: 'Push an image'
  inputs:
    azureSubscriptionEndpoint: 'DemoSPNConnection'
    azureContainerRegistry: demo.azurecr.io
    command: 'Push an image'

trigger:
  batch: true
  branches:
    include:
    - master
  paths:
    exclude:
    - readme.md

azure-pipelines.ci.yaml

resources:
- repo: self
queue:
  name: Hosted Ubuntu 1604
variables:
- group: Artifacts

steps:
- task: Docker@1
  displayName: 'Build an image'
  inputs:
    azureSubscriptionEndpoint: 'DemoSPNConnection'
    azureContainerRegistry: demo.azurecr.io
    arguments: '--build-arg ARTIFACTS_ENDPOINT=$(artifactsEndpoint) --build-arg ACCESS_TOKEN=$(artifactsAccessToken)'

trigger: none

Dockerfile

FROM microsoft/dotnet:2.2.100-sdk AS build-env
WORKDIR /app

# Credit: https://stackoverflow.com/questions/53419491/azure-artifacts-gives-unauthorized-when-trying-to-build-dockerfile/53510966#53510966
# Personal access token to access Artifacts feed
ARG ACCESS_TOKEN
ARG ARTIFACTS_ENDPOINT

# Install the Credential Provider to configure the access
RUN wget -qO- https://raw.githubusercontent.com/Microsoft/artifacts-credprovider/master/helpers/installcredprovider.sh | bash

# Configure the environment variables
ENV NUGET_CREDENTIALPROVIDER_SESSIONTOKENCACHE_ENABLED true
ENV VSS_NUGET_EXTERNAL_FEED_ENDPOINTS "{\"endpointCredentials\": [{\"endpoint\":\"${ARTIFACTS_ENDPOINT}\", \"password\":\"${ACCESS_TOKEN}\"}]}"

# copy everything and build the project
COPY ./src ./
RUN dotnet restore -s ${ARTIFACTS_ENDPOINT} api/*.csproj
RUN dotnet publish api/*.csproj -c Release -o out

# build runtime image
FROM microsoft/dotnet:2.2-aspnetcore-runtime
WORKDIR /app
COPY --from=build-env /app/api/out ./
ENTRYPOINT ["dotnet", "api.dll"]
EXPOSE 443

how the processes of build works in terms of containerized application because in our case it is magneto image which is 1.6GB and building that size of image is taking too much time how we can overcome this?

Instead of creating and using Access Token you can use NuGetAuthenticate task and then use VSS_NUGET_ACCESSTOKEN env variable.

  - task: NuGetAuthenticate@0

  - task: Docker@2
    inputs:
      ...
      arguments: '--build-arg ACCESS_TOKEN=$(VSS_NUGET_ACCESSTOKEN)'