How to setup Gitlab CI job artifacts for a C# project?

Question

This is how I would do it using Github:

jobs:
  run-tests:

    runs-on: ubuntu-latest
    
    defaults:
      run:
        working-directory: ./MyApp

    steps:
    - uses: actions/checkout@v2
    
    - name: Setup .NET
      uses: actions/setup-dotnet@v1
      with:
        dotnet-version: 5.0.x

    - name: Restore dependencies
      run: dotnet restore
      
    - name: Build project
      run: dotnet build --no-restore
      
    - name: Run tests
      run: dotnet test --no-build

This time on Gitlab my project solution file is in the root directory of the repository. I created a .gitlab-ci.yml file and started with

image: mcr.microsoft.com/dotnet/sdk:5.0

stages:
  - restore-dependencies
  - build-solution
  - run-tests

restore-dependencies:
  stage: restore-dependencies
  script:
    - dotnet restore --packages packages
  artifacts:
    paths:
      - packages

build-solution:
  stage: build-solution
  script:
    - dotnet build --no-restore --source packages --output build
  artifacts:
    paths:
      - build
  dependencies:
    - restore-dependencies

run-tests:
  stage: run-tests
  script:
    - dotnet test --no-build --output build
  dependencies:
    - build-solution

The first job passes but the second one fails because it can't find the restored files from the first job. So my solution has a TestProject1 and the second job is not able to find a resource file in ...\TestProject1\obj\project.assets.json

How can I fix the pipeline configuration?

Answer 1

Maybe it might me worth a try to define the pipeline as a Directed Acyclic Graph (DAG), so instead of defining dependencies in your step, you could define needs. When a Job is defined with the needs keyword it will only start if all dependent previous jobs succeeded (except they are allowed to fail). The advantage of the needs keyword here would be that you can explicitly configure the step to download the artifacts from the previous jobs

image: mcr.microsoft.com/dotnet/sdk:5.0

stages:
  - restore-dependencies
  - build-solution
  - run-tests

restore-dependencies:
  stage: restore-dependencies
  script:
    - dotnet restore --packages packages
  artifacts:
    paths:
      - packages

build-solution:
  stage: build-solution
  script:
    - dotnet build --no-restore --source packages --output build
  artifacts:
    paths:
      - build
  needs:
    - job: restore-dependencies
      artifacts: true

run-tests:
  stage: run-tests
  script:
    - dotnet test --no-build --output build
  needs:
    - job: build-solution
      artifacts: true

Answer 2

You are using separate jobs to run each command. Gitlab runs each job in a new container, destroying any context from the previous command except for explicitly specified artifacts. To run sequential commands like you have configured in Github actions, you can just add multiple steps which will run sequentially in the same image, preserving the context between commands.

stages:
 - build-solution

run-tests:
  image: mcr.microsoft.com/dotnet/sdk:5.0
  stage: build-solution
  script:
    - dotnet restore
    - dotnet build --no-restore
    - dotnet test --no-build

Alternatively, you could use artifacts and flags to transfer the output of each command between jobs:

I believe artifacts have to be relative paths to your $CI_PROJECT_DIR (source), and according to the dotnet restore documentation the default write location is in the home directory.

You could try specifying the write location as packages/ with dotnet restore --packages packages (source)

and the read location as packages/ with dotnet build --source packages (source)

Then you would need to specify this artifact like:

artifacts:
  paths:
    - packages

You would need a similar usage of the --output flag to save your build artifact in the build-solution stage.

This is more complicated, but may be desired in some cases.