Quickstart: Create a GitHub workflow to publish an app

2022-10-07

In this quickstart, you will learn how to create a GitHub workflow to publish your .NET app from source code. Automatically publishing your .NET app from GitHub to a destination is referred to as a continuous deployment (CD). There are many possible destinations to publish an application, in this quickstart you'll publish to Azure.

Prerequisites

A GitHub account.
A .NET source code repository.
An Azure account with an active subscription. Create an account for free.
An ASP.NET Core web app.
An Azure App Service resource.

Add publish profile

To publish the app to Azure, open the Azure portal for the App Service instance of the application. In the resource Overview, select Get publish profile and save the *.PublishSetting file locally.

Warning

The publish profile contains sensitive information, such as credentials for accessing your Azure App Service resource. This information should always be treated very carefully.

In the GitHub repository, navigate to Settings and select Secrets from the left navigation menu. Select New repository secret, to add a new secret.

Enter AZURE_PUBLISH_PROFILE as the Name, and paste the XML content from the publish profile into the Value text area. Select Add secret. For more information, see Encrypted secrets.

Create a workflow file

In the GitHub repository, add a new YAML file to the .github/workflows directory. Choose a meaningful file name, something that will clearly indicate what the workflow is intended to do. For more information, see Workflow file.

Important

GitHub requires that workflow composition files to be placed within the .github/workflows directory.

Workflow files typically define a composition of one or more GitHub Action via the jobs.<job_id>/steps[*]. For more information, see, Workflow syntax for GitHub Actions.

Create a new file named publish-app.yml, copy and paste the following YML contents into it:

name: publish

on:
  push:
    branches: [ production ]

env:
  AZURE_WEBAPP_NAME: DotNetWeb
  AZURE_WEBAPP_PACKAGE_PATH: '.' # Set this to the path to your web app project, defaults to the repository root:
  DOTNET_VERSION: '6.0.401' # The .NET SDK version to use

jobs:
  publish:

    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v3
    - name: Setup .NET Core
      uses: actions/setup-dotnet@v3
      with:
        dotnet-version: ${{ env.DOTNET_VERSION }}

    - name: Install dependencies
      run: dotnet restore
      
    - name: Build
      run: |
        cd DotNet.WebApp
        dotnet build --configuration Release --no-restore
        dotnet publish -c Release -o ../dotnet-webapp -r linux-x64 --self-contained true /p:UseAppHost=true
    - name: Test
      run: |
        cd DotNet.WebApp.Tests
        dotnet test --no-restore --verbosity normal
      
    - uses: azure/webapps-deploy@v2
      name: Deploy
      with:
        app-name: ${{ env.AZURE_WEBAPP_NAME }}
        publish-profile: ${{ secrets.AZURE_PUBLISH_PROFILE }}
        package: '${{ env.AZURE_WEBAPP_PACKAGE_PATH }}/dotnet-webapp'

In the preceding workflow composition:

The name: publish defines the name, "publish" will appear in workflow status badges.
```
name: publish
```
The on node signifies the events that trigger the workflow:
```
on:
  push:
    branches: [ production ]
```
- Triggered when a push occurs on the production branch.
The env node defines named environment variables (env var).
```
env:
  AZURE_WEBAPP_NAME: DotNetWeb
  AZURE_WEBAPP_PACKAGE_PATH: '.' # Set this to the path to your web app project, defaults to the repository root:
  DOTNET_VERSION: '6.0.401' # The .NET SDK version to use
```
- The environment variable AZURE_WEBAPP_NAME is assigned the value DotNetWeb.
- The environment variable AZURE_WEBAPP_PACKAGE_PATH is assigned the value '.'.
- The environment variable DOTNET_VERSION is assigned the value '6.0.401'. The environment variable is later referenced to specify the dotnet-version of the actions/setup-dotnet@v3 GitHub Action.

The jobs node builds out the steps for the workflow to take.

jobs:
  publish:

    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v3
    - name: Setup .NET Core
      uses: actions/setup-dotnet@v3
      with:
        dotnet-version: ${{ env.DOTNET_VERSION }}

    - name: Install dependencies
      run: dotnet restore
      
    - name: Build
      run: |
        cd DotNet.WebApp
        dotnet build --configuration Release --no-restore
        dotnet publish -c Release -o ../dotnet-webapp -r linux-x64 --self-contained true /p:UseAppHost=true
    - name: Test
      run: |
        cd DotNet.WebApp.Tests
        dotnet test --no-restore --verbosity normal
      
    - uses: azure/webapps-deploy@v2
      name: Deploy
      with:
        app-name: ${{ env.AZURE_WEBAPP_NAME }}
        publish-profile: ${{ secrets.AZURE_PUBLISH_PROFILE }}
        package: '${{ env.AZURE_WEBAPP_PACKAGE_PATH }}/dotnet-webapp'

There is a single job, named publish that will run on the latest version of Ubuntu.
The actions/setup-dotnet@v3 GitHub Action is used to set up the .NET SDK with the specified version from the DOTNET_VERSION environment variable.
The dotnet restore command is called.
The dotnet build command is called.
The dotnet publish command is called.
The dotnet test command is called.
The azure/webapps-deploy@v2 GitHub Action deploys the app with the given publish-profile and package.
- The publish-profile is assigned from the AZURE_PUBLISH_PROFILE repository secret.

Create a workflow status badge

It's common nomenclature for GitHub repositories to have a README.md file at the root of the repository directory. Likewise, it's nice to report the latest status for various workflows. All workflows can generate a status badge, which are visually appealing within the README.md file. To add the workflow status badge:

From the GitHub repository select the Actions navigation option.
All repository workflows are displayed on the left-side, select the desired workflow and the ellipsis (...) button.
- The ellipsis (...) button expands the menu options for the selected workflow.
Select the Create status badge menu option.
Select the Copy status badge Markdown button.
Paste the Markdown into the README.md file, save the file, commit and push the changes.