• Summary:
• Contents:

Environment Variables in Docker

Ref: https://learn.cantrill.io/courses/docker-fundamentals/lectures/44660845 =OR= https://www.youtube.com/watch?v=fEACChbNoqk

GitHub: https://github.com/acantril/docker-fundamentals/blob/main/docker-container-environment-variables/instructions.md

• 🔧 Environment variables allow for customizable environment configuration
• Key↔value pairs
  • Convention: KEY:value
  • Run container with environment variable: docker run <imgID> -e KEY:value
• Inspecting a container will show configured environment variables under “ENV”
  • e.g. “PATH” → indicates where the terminal opens & executes inside the container

Deploying simple WordPress app

Ref: https://learn.cantrill.io/courses/docker-fundamentals/lectures/44660845 =OR= https://www.youtube.com/watch?v=fEACChbNoqk

GitHub: https://github.com/acantril/docker-fundamentals/blob/main/docker-container-environment-variables/instructions.md

• 💡 WordPress commonly used as example app for simple deployments

  • Simple multi-tiered app (has DB and WEB components)

• Run MariaDB for WordPress in a Docker container:

  docker run \\
  --name db \\
  -e MYSQL_ROOT_PASSWORD=somewordpress \\
  -e MYSQL_PASSWORD=wordpress \\
  -e MYSQL_DATABASE=wordpress \\
  -e MYSQL_USER=wordpress \\
  -d \\
  mariadb:10.6.4-focal \\
  --default-authentication-plugin=mysql_native_password
  

• Environment variables for configuring MariaDB:

  • MYSQL_ROOT_PASSWORD sets the DB root password
  • MYSQL_DATABASE creates a DB with the name of the environment variable
  • MYSQL_USER creates a DB user
  • MYSQL_PASSWORD creates a password for the DB user

• ❗ Storage of this MariaDB container is internal and ephemeral

• With an additional container running a phpmyadmin DB management app, we can connect to this MariaDB and store WordPress pages (check video for more details)

Deploying WordPress app with persistent storage