Configuration: Database¶

This page covers database setup for Kairos.

H2 (default)¶

H2 file mode works out of the box and is suitable for local and small setups.

spring.datasource.url=jdbc:h2:file:./kairos;AUTO_SERVER=TRUE
spring.datasource.driver-class-name=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
spring.jpa.hibernate.ddl-auto=update
spring.flyway.enabled=true
spring.flyway.baseline-on-migrate=true
spring.flyway.baseline-version=0

The H2 web console is available at http://localhost:8080/h2-console when spring.h2.console.enabled=true.

PostgreSQL¶

For production workloads, PostgreSQL is recommended.

spring.datasource.url=jdbc:postgresql://localhost:5432/kairos
spring.datasource.driver-class-name=org.postgresql.Driver
spring.datasource.username=kairos
spring.datasource.password=secret
spring.jpa.hibernate.ddl-auto=update
spring.flyway.enabled=true
spring.flyway.baseline-on-migrate=true
spring.flyway.baseline-version=0

Environment variable equivalent:

SPRING_DATASOURCE_URL=jdbc:postgresql://db:5432/kairos
SPRING_DATASOURCE_USERNAME=kairos
SPRING_DATASOURCE_PASSWORD=secret

Example docker-compose with PostgreSQL:

version: "3.9"
services:
  db:
    image: postgres:16-alpine
    environment:
      POSTGRES_DB: kairos
      POSTGRES_USER: kairos
      POSTGRES_PASSWORD: secret
    volumes:
      - pgdata:/var/lib/postgresql/data

  kairos:
    image: ghcr.io/wenisch-tech/kairos:latest
    ports:
      - "8080:8080"
    environment:
      SPRING_DATASOURCE_URL: jdbc:postgresql://db:5432/kairos
      SPRING_DATASOURCE_USERNAME: kairos
      SPRING_DATASOURCE_PASSWORD: secret
    depends_on:
      - db

volumes:
  pgdata:

Flyway Migrations¶

Kairos uses Flyway for startup migrations.

Existing databases without a Flyway history table are baselined automatically.
Pending migrations are then applied in order.
No manual SQL migration steps are required for normal upgrades.