Implementing CI/CD with Jenkins Declarative Pipeline for .NET Core Applications

Jenkins offers several ways to achieve CI/CD, including Blue Ocean, Freestyle projects, and Declarative Pipelines. This guide focuses on automating integration and deployment for a .NET Core application using a Declarative Pipeline.

In the pipeline configuration, select Pipeline script and define environment variables and triggers as shown below:

pipeline{
    agent any

    environment {
        dotnet ='C:\Program Files (x86)\dotnet\'
    }

    triggers {
        pollSCM 'H * * * *'
    }
}

The first CI step checks out the source code from Git:

stages{ stage('Checkout') {    steps {     git credentialsId: 'Give Your Credential ID', url: 'https://github.com/YourAcc/YourRepoName.git/', branch: 'Branch on which you want to set the CI'     }  }

Next, restore the project's NuGet packages:

stage('Restore packages'){
   steps{
      bat "dotnet restore YourProjectPath\Your_Project.csproj"
     }
}

Clean the build output:

stage('Clean'){
  steps{
    bat "dotnet clean YourProjectPath\Your_Project.csproj"
  }
}

Build the project, producing DLLs in bin\Debug\netcoreapp2.x :

stage('Build'){
   steps{
      bat "dotnet build YourProjectPath\Your_Project.csproj --configuration Release"
    }
}

Optionally integrate SonarQube for code quality analysis, then add automated testing stages:

stage('Test: Unit Test'){
   steps {
     bat "dotnet test YourProjectPath\UnitTest_Project.csproj"
     }
  }

 stage('Test: Integration Test'){
    steps {
       bat "dotnet test ProjectPath\IntegrateTest_Project.csproj"
      }
   }

Finally, publish the compiled artifacts and send a notification email:

stage('Publish'){
     steps{       bat "dotnet publish YourProjectPath\Your_Project.csproj "
     }}

post{
  always{
    emailext body: "${currentBuild.currentResult}: Job   ${env.JOB_NAME} build ${env.BUILD_NUMBER}
 More info at: ${env.BUILD_URL}",
    recipientProviders: [[$class: 'DevelopersRecipientProvider'], [$class: 'RequesterRecipientProvider']],
    subject: "Jenkins Build ${currentBuild.currentResult}: Job ${env.JOB_NAME}"
    }
  }

The complete pipeline flow is: Checkout → Restore → Clean → Build → Test → Publish.