Deploy Spring Boot

This guide deploys a Spring Boot application and connects it to a managed PostgreSQL database. For the shared deploy flow, see Deploy from GitHub.

Prepare Your App

Bind the Port

Spring Boot already listens on 0.0.0.0. Drive the port from the environment, with a default for local development:

server.port=${PORT:8080}

Do not set server.address to localhost, or the app becomes unreachable. Expose the same port in Networking.

Deploy

Create an application from your repository. Spring Boot has first class Buildpacks support, so a build with no Dockerfile works out of the box. For a Dockerfile, the JAR runs with java -jar. The start command runs as a direct exec, so a wildcard path needs a shell:

sh -c "java -jar target/*.jar"

A fixed JAR name copied in your Dockerfile avoids the wildcard entirely.

Connect a Database

Create a managed PostgreSQL database. Spring's relaxed binding lets you set datasource properties from environment variables:

SPRING_DATASOURCE_URL=jdbc:postgresql://host:5432/dbname?sslmode=require
SPRING_DATASOURCE_USERNAME=...
SPRING_DATASOURCE_PASSWORD=...

Connections require SSL, so keep ?sslmode=require in the URL. Copy the JDBC formatted string from the database's Connection panel.

Run Migrations

Use Flyway or Liquibase, which run automatically on startup and take a lock that is safe across multiple instances. This is the cleanest fit for Out Plane, which has no separate pre deploy hook.

Environment Variables

Next Steps