Docker Book

Notes for upcoming book on Docker and PHP.

Installing Docker

• Point to instructions on Docker website, no point in duplicating these
• Make sure you are running the latest version
• Use upstream repositories as the distribution ones are too out of date
• If running Ubuntu, use LTS as the host

Hello World

• docker run --rm hello-world
• Include example output for checking
• Explain use of --rm flag - without this we end up with lots of stopped but not removed images

Basic PHP example

• docker run --rm php:7.4-apache-buster php -v, show output

Dockerfile:

 FROM php:7.4-apache-buster
 COPY index.php /var/www/html/index.php

index.php:

 <?php phpinfo();

• docker build -t phpinfo:latest .
• docker run --rm -p 8000:80 phpinfo
• Visit localhost:8000 in browser
• Ctrl+C terminates container and Docker will remove it automatically due to the --rm flag

Docker Compose

Docker Composer (docker-compose) is a way to configure Docker with YAML. For example, you can specify environment variables in a YAML list, instead of having to supply them all on the command line.

If you are adding Docker to a project for the first time, you should use Docker Compose by default.