Overview:

• Convert a Docker Compose configuration to work with Web App for Containers
• Deploy a multi-container app to Azure
• Add application settings
• Use persistent storage for your containers
• Connect to Azure Database for MySQL
• Troubleshoot errors

Recap

Before we get started, below is just a Recap, overall steps required for Containers:

Demo (Summary):

Demo (Step-by-step)

Old code:

version: '3.3'
 
services:
   wordpress:
     image: mcr.microsoft.com/azuredocs/multicontainerwordpress
     ports:
       - "8000:80"
     restart: always
 
   redis:
     image: mcr.microsoft.com/oss/bitnami/redis:6.0.8
     environment: 
      - ALLOW_EMPTY_PASSWORD=yes
     restart: always
 

New Code:

version: '3.3'
 
services:
   db:
     image: mysql:5.7
     volumes:
       - db_data:/var/lib/mysql
     restart: always
     environment:
       MYSQL_ROOT_PASSWORD: somewordpress
       MYSQL_DATABASE: wordpress
       MYSQL_USER: wordpress
       MYSQL_PASSWORD: wordpress
 
   wordpress:
     depends_on:
       - db
     image: wordpress:latest
     ports:
       - "8000:80"
     restart: always
     environment:
       WORDPRESS_DB_HOST: db:3306
       WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: wordpress
volumes:
    db_data:

 create a multi-container app in Web App for Containers.

Congratulations, you’ve created a multi-container app in Web App for Containers.

Next you’ll configure your app to use Azure Database for MySQL. Don’t install WordPress at this time.

Connect to production database 

Configure server firewall

Create a firewall rule for your MySQL server to allow client connections by using the az mysql server firewall-rule create command. When both starting IP and end IP are set to 0.0.0.0, the firewall is only opened for other Azure resources.

Create the WordPress database

Configure database variables in WordPress

Use a custom image for MySQL TLS/SSL and other configurations

By default, TLS/SSL is used by Azure Database for MySQL. WordPress requires additional configuration to use TLS/SSL with MySQL. The WordPress ‘official image’ doesn’t provide the additional configuration, but a custom image has been prepared for your convenience. In practice, you would add desired changes to your own image.

Changed Line#18

Updated Code:

Update app with new configuration

Browse to the app

Browse to the deployed app at (http://<app-name&gt;.azurewebsites.net). The app is now using Azure Database for MySQL.

Add persistent storage

Your multi-container is now running in Web App for Containers. However, if you install WordPress now and restart your app later, you’ll find that your WordPress installation is gone. This happens because your Docker Compose configuration currently points to a storage location inside your container. The files installed into your container don’t persist beyond app restart.

In this section, you’ll add persistent storage to your WordPress container.

Configure environment variables

To use persistent storage, you’ll enable this setting within App Service. To make this change, use the az webapp config appsettings set command in Cloud Shell. App settings are case-sensitive and space-separated.

To use persistent storage, you’ll enable this setting within App Service. To make this change, use the az webapp config appsettings set command in Cloud Shell. App settings are case-sensitive and space-separated.

Modify configuration file

The volumes option maps the file system to a directory within the container. ${WEBAPP_STORAGE_HOME} is an environment variable in App Service that is mapped to persistent storage for your app. You’ll use this environment variable in the volumes option so that the WordPress files are installed into persistent storage instead of the container.

Make the following modifications to the file:

In the wordpress section, add a volumes option so it looks like the following code:

Update app with new configuration/Compose 🙂

Browse to the app

The WordPress container is now using Azure Database for MySQL and persistent storage.

Conclusion

In conclusion, Azure App Service’s support for multi-container applications represents a significant advancement in cloud application deployment. It offers a robust platform for developers to deploy and manage containerized applications with ease and confidence, paving the way for innovative and scalable cloud solutions. 🚀🔐👨‍💻

References:

https://learn.microsoft.com/en-us/azure/app-service/tutorial-multi-container-app