Challenge - Compose
- Docker & Kubernetes course
- Beginner
- Lesson 81/82
- 5 min
Combine web and database with compose.
Challenge: a Compose stack
WordPress + MySQL is the classic Compose example. In this challenge you'll define a two-service stack in a single file: the database will persist in a named volume, WordPress will connect to the database by service name, and only WordPress will publish a port.
services:
db:
image: mysql:8
environment:
MYSQL_ROOT_PASSWORD: gizli
MYSQL_DATABASE: wp
volumes:
- dbveri:/var/lib/mysql
wordpress:
image: wordpress:6
ports:
- "8080:80"
environment:
WORDPRESS_DB_HOST: db
WORDPRESS_DB_PASSWORD: gizli
depends_on:
- db
volumes:
dbveri:Practice compose.yaml
Write the compose.yaml from the card: the db service (mysql:8, MYSQL_ROOT_PASSWORD: gizli, dbveri:/var/lib/mysql); the wordpress service (wordpress:6, "8080:80", WORDPRESS_DB_HOST: db, db under depends_on); dbveri: under a top-level volumes.
Starter code
# compose.yaml
# buraya yazSample solution
# compose.yaml
services:
db:
image: mysql:8
environment:
MYSQL_ROOT_PASSWORD: gizli
volumes:
- dbveri:/var/lib/mysql
wordpress:
image: wordpress:6
ports:
- "8080:80"
environment:
WORDPRESS_DB_HOST: db
depends_on:
- db
volumes:
dbveri:Expected output
[+] Running 3/3 ✔ Volume "proje_dbveri" Created ✔ Container proje-db-1 Started ✔ Container proje-wordpress-1 Started
Practice Manage the stack
Write three commands: start the stack in the background; show the status of the services; follow the logs of the wordpress service live.
Starter code
# buraya yazSample solution
docker compose up -d
docker compose ps
docker compose logs -f wordpressExpected output
[+] Running 2/2 ✔ Container proje-db-1 Started ✔ Container proje-wordpress-1 Started NAME SERVICE STATUS PORTS proje-db-1 db Up 5 seconds 3306/tcp, 33060/tcp proje-wordpress-1 wordpress Up 4 seconds 0.0.0.0:8080->80/tcp
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Why does WORDPRESS_DB_HOST take the value db?
- db is an IP address
- It's MySQL's default name
- It was chosen arbitrarily
- On the Compose network, the service name is the DNS name Correct answer
Explanation: Containers find each other by name on the shared default network.
2 Start the stack in the background.
docker compose up ____docker compose up -dExplanation: -d (detached) releases the terminal.
3 Match.
| Term | Meaning |
|---|---|
dbveri |
Persistent MySQL data |
8080:80 |
Only WordPress published |
depends_on |
Start order |
WORDPRESS_DB_HOST: db |
Connection by service name |