Lesson Notes

Dockerization Lesson Notes

Dockerization Lesson Presentation

Video

Docker default bridge network

• What if we have an application with more than one container.
• Ex; WordPress rich content management system uses apache httpd and mysql servers.
• -e, --env list Set environment variables.

docker run --name mysql -e MYSQL_ROOT_PASSWORD=P@ssw0rd -d mysql:5.7
docker run --name mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=P@ssw0rd \
       -d mysql:5.7
hostname
# hostname.lan
docker run -it --rm mysql:5.7 mysql -hhostname.lan -uroot -pP@ssw0rd
docker run -it --rm mysql:5.7 mysql -h"$(hostname)" -uroot -pP@ssw0rd
# OR
docker run -it --rm mysql:5.7 mysql -h`hostname` -uroot -pP@ssw0rd

User-defined bridge network

• User-defined bridges provide automatic DNS resolution between containers.
• User-defined bridges provide better isolation.
• Containers can be attached and detached from user-defined networks on the fly.
• Each user-defined network creates a configurable bridge.
• Linked containers on the default bridge network share environment variables.

Docker Network Commands

• create Create a network.
• ls List networks.
• connect Connect a container to a network.
• inspect Display detailed information on one or more networks.
• rm Deletes one or more networks.

docker network create wp-network
docker network connect wp-network mysql
docker network inspect wp-network
docker run --name wordpress --network wp-network -p 8080:80 \
      -e WORDPRESS_DB_HOST=mysql -e WORDPRESS_DB_NAME=wp_db \
      -e WORDPRESS_DB_USER=root -e WORDPRESS_DB_PASSWORD=P@ssw0rd \
      -d wordpress
docker network inspect wp-network
docker network rm wp-network