Deploying Docker to Azure App Service

Introduction

This guide explains how to use GitHub Actions to build and deploy a Docker container to Azure App Service.

Prerequisites

Before creating your GitHub Actions workflow, you will first need to complete the following setup steps:

1. Create an Azure App Service plan.

   For example, you can use the Azure CLI to create a new App Service plan:

   Bash

   az appservice plan create \
      --resource-group MY_RESOURCE_GROUP \
      --name MY_APP_SERVICE_PLAN \
      --is-linux
   

   In the command above, replace MY_RESOURCE_GROUP with your pre-existing Azure Resource Group, and MY_APP_SERVICE_PLAN with a new name for the App Service plan.

   See the Azure documentation for more information on using the Azure CLI:

   • For authentication, see "Sign in with Azure CLI."
   • If you need to create a new resource group, see "az group."

2. Create a web app.

   For example, you can use the Azure CLI to create an Azure App Service web app:

   Bash

   az webapp create \
       --name MY_WEBAPP_NAME \
       --plan MY_APP_SERVICE_PLAN \
       --resource-group MY_RESOURCE_GROUP \
       --deployment-container-image-name nginx:latest
   

   In the command above, replace the parameters with your own values, where MY_WEBAPP_NAME is a new name for the web app.

3. Configure an Azure publish profile and create an AZURE_WEBAPP_PUBLISH_PROFILE secret.

   Generate your Azure deployment credentials using a publish profile. For more information, see "Generate deployment credentials" in the Azure documentation.

   In your GitHub repository, create a secret named AZURE_WEBAPP_PUBLISH_PROFILE that contains the contents of the publish profile. For more information on creating secrets, see "Encrypted secrets."

4. Set registry credentials for your web app.

   Create a personal access token with the repo and read:packages scopes. For more information, see "Managing your personal access tokens."

   Set DOCKER_REGISTRY_SERVER_URL to https://ghcr.io, DOCKER_REGISTRY_SERVER_USERNAME to the GitHub username or organization that owns the repository, and DOCKER_REGISTRY_SERVER_PASSWORD to your personal access token from above. This will give your web app credentials so it can pull the container image after your workflow pushes a newly built image to the registry. You can do this with the following Azure CLI command:

   az webapp config appsettings set \
        --name MY_WEBAPP_NAME \
        --resource-group MY_RESOURCE_GROUP \
        --settings DOCKER_REGISTRY_SERVER_URL=https://ghcr.io DOCKER_REGISTRY_SERVER_USERNAME=MY_REPOSITORY_OWNER DOCKER_REGISTRY_SERVER_PASSWORD=MY_PERSONAL_ACCESS_TOKEN

5. Optionally, configure a deployment environment. Environments are used to describe a general deployment target like production, staging, or development. When a GitHub Actions workflow deploys to an environment, the environment is displayed on the main page of the repository. You can use environments to require approval for a job to proceed, restrict which branches can trigger a workflow, or limit access to secrets. For more information about creating environments, see "Using environments for deployment."

Creating the workflow

Once you've completed the prerequisites, you can proceed with creating the workflow.

The following example workflow demonstrates how to build and deploy a Docker container to Azure App Service when there is a push to the main branch.

Ensure that you set AZURE_WEBAPP_NAME in the workflow env key to the name of the web app you created.

If you configured a deployment environment, change the value of environment to be the name of your environment. If you did not configure an environment, delete the environment key.

# This workflow uses actions that are not certified by GitHub.
# They are provided by a third-party and are governed by
# separate terms of service, privacy policy, and support
# documentation.

# GitHub recommends pinning actions to a commit SHA.
# To get a newer version, you will need to update the SHA.
# You can also reference a tag or branch, but the action may change without warning.

name: Build and deploy a container to an Azure Web App

env:
  AZURE_WEBAPP_NAME: MY_WEBAPP_NAME   # set this to your application's name

on:
  push:
    branches:
      - main

permissions:
  contents: 'read'
  packages: 'write'

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v2

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2

      - name: Log in to GitHub container registry
        uses: docker/login-action@v2
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Lowercase the repo name
        run: echo "REPO=${GITHUB_REPOSITORY,,}" >>${GITHUB_ENV}

      - name: Build and push container image to registry
        uses: docker/build-push-action@v4
        with:
          push: true
          tags: ghcr.io/${{ env.REPO }}:${{ github.sha }}
          file: ./Dockerfile

  deploy:
    runs-on: ubuntu-latest

    needs: build

    environment:
      name: 'production'
      url: ${{ steps.deploy-to-webapp.outputs.webapp-url }}

    steps:
      - name: Lowercase the repo name
        run: echo "REPO=${GITHUB_REPOSITORY,,}" >>${GITHUB_ENV}

      - name: Deploy to Azure Web App
        id: deploy-to-webapp
        uses: azure/webapps-deploy@85270a1854658d167ab239bce43949edb336fa7c
        with:
          app-name: ${{ env.AZURE_WEBAPP_NAME }}
          publish-profile: ${{ secrets.AZURE_WEBAPP_PUBLISH_PROFILE }}
          images: 'ghcr.io/${{ env.REPO }}:${{ github.sha }}'

Additional resources

The following resources may also be useful:

• For the original starter workflow, see azure-container-webapp.yml in the GitHub Actions starter-workflows repository.
• The action used to deploy the web app is the official Azure Azure/webapps-deploy action.
• For more examples of GitHub Action workflows that deploy to Azure, see the actions-workflow-samples repository.