Problemet beror på referens till localhost i jdbc url.
Nedanstående konfiguration bör fungera.
**docker-compose.yml**
version: '3'
services:
docker-mysql:
image: mysql:5.7
environment:
- MYSQL_ROOT_PASSWORD=root
- MYSQL_DATABASE=database
- MYSQL_USER=root
- MYSQL_PASSWORD=root
ports:
- 3307:3306
app:
image: app:latest
ports:
- 8091:8091
environment:
SPRING_DATASOURCE_URL: jdbc:mysql://docker-mysql:3306/database?autoReconnect=true&useSSL=false
depends_on:
- docker-mysql