Putting it together - compose
- Docker & Kubernetes course
- Beginner
- Lesson 65/82
- 5 min
Combine all services and run with compose up.
Putting it together: the full stack
Putting the parts together, the stack of API, PostgreSQL and Redis lives in a single file. The API takes the connection information from environment variables using the service names:
services:
api:
build: .
ports: ["8000:8000"]
environment:
DATABASE_URL: postgresql://app:gizli@db:5432/app
REDIS_URL: redis://cache:6379
depends_on:
db: {condition: service_healthy}
cache: {condition: service_started}
db:
image: postgres:16
...
cache:
image: redis:7Everyday commands
docker compose up -d # start (create/update what's needed)
docker compose ps # status
docker compose logs -f api # follow the api logs
docker compose exec db psql -U app # a command in the service container
docker compose restart api # restart
docker compose down # remove (volumes stay)The commands are run in the folder containing the compose file; from elsewhere -f path/compose.yaml is given.
Practice The full stack
Write a compose.yaml: the api service has build: ., port "8000:8000", REDIS_URL: redis://cache:6379 under environment, and cache under depends_on; the cache service uses the redis:7 image.
Starter code
# compose.yaml
# buraya yazSample solution
# compose.yaml
services:
api:
build: .
ports:
- "8000:8000"
environment:
REDIS_URL: redis://cache:6379
depends_on:
- cache
cache:
image: redis:7Expected output
[+] Running 3/3 ✔ Network proje_default Created ✔ Container proje-cache-1 Started ✔ Container proje-api-1 Started
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Which rebuilds only the api image and updates the stack after a code change?
- docker build compose.yaml
- docker compose ps --build
- docker compose up -d --build api Correct answer
- docker compose down -v
Explanation: The unchanged db and cache containers aren't touched.
2 Run a command in a service container.
docker compose ____ db psql -U appdocker compose exec db psql -U appExplanation: compose exec runs in the running service container.
3 Match.
| Term | Meaning |
|---|---|
up -d --build |
Rebuild and start |
logs -f api |
Follow api logs |
exec db |
Command in db |
down |
Remove, volumes stay |