# Spring Boot profiles, config import and config trees

Companion project for [**Spring Boot Profiles Done Right**](https://ankurm.com/) on ankurm.com.

The question the project answers: you set a value in `application-prod.yaml`, deployed with
`prod` active, and the old value is still in effect. Why?

## Versions

| | |
|---|---|
| Spring Boot | 4.1.1 |
| Spring Framework | 7.0.9 |
| JDK | Eclipse Temurin 25.0.4.1 (LTS) |

## Quickstart

```bash
export JAVA_HOME=/path/to/jdk-25
mvn -DskipTests package
./scripts/run-all.sh          # regenerate every transcript in docs/output/
mvn test                      # 6 contract tests
```

## Profiles

| Profile | What it demonstrates |
|---|---|
| `prod` | a profile group expanding to `prod`, `prod-db`, `prod-metrics` |
| `import` | `spring.config.import`, and the imported file winning |
| `multidoc` | one file, three documents, activated by condition |
| `badactivation` | `spring.profiles.active` set from a profile-specific document — refused |
| `staging` | the conditional document inside `application-multidoc.yaml` |

## Endpoints

| Endpoint | Purpose |
|---|---|
| `GET /precedence?name=` | every source holding a property, ranked, with file and line |
| `GET /sources` | the live property-source stack in precedence order |

Diagnostics. Delete before shipping, or use Actuator's `/actuator/env`, which sanitises.

## Documentation

1. [The precedence list](docs/01-the-precedence-list.md)
2. [Profiles: files, documents and groups](docs/02-profiles.md)
3. [Seeing precedence instead of reasoning about it](docs/03-seeing-precedence.md)
4. [Why your profile-specific file lost](docs/04-why-your-profile-file-lost.md)
5. [`spring.config.import`](docs/05-config-import.md)
6. [Config trees and Kubernetes ConfigMaps](docs/06-config-trees-and-configmaps.md)

## Captured output

| File | Produced by |
|---|---|
| [`00-versions.txt`](docs/output/00-versions.txt) | `scripts/demo-versions.sh` |
| [`01-precedence.txt`](docs/output/01-precedence.txt) | `scripts/demo-precedence.sh` |
| [`02-profile-file-loses.txt`](docs/output/02-profile-file-loses.txt) | `scripts/demo-profile-file-loses.sh` |
| [`03-config-tree.txt`](docs/output/03-config-tree.txt) | `scripts/demo-config-tree.sh` |
| [`04-import-and-multidoc.txt`](docs/output/04-import-and-multidoc.txt) | `scripts/demo-import-and-multidoc.sh` |

## The short answer

Config data — every file you write, profile-specific ones included — is item 3 in Spring Boot's
documented precedence list. OS environment variables are item 5. Later items win. A
profile-specific file beats other files and loses to the weakest environment variable on the
host.

## The one that surprises people

`spring.config.import` does not behave like `#include`. The **imported** file is processed after
the file that declared the import, so it **wins**. Import a shared baseline expecting to
override it and every key it sets will quietly beat yours.