Configuration system

ARender is built on Spring Boot. All services follow the Spring Boot externalized configuration model. This page describes how configuration sources are resolved and how to override properties at each layer.

Precedence hierarchy

Spring Boot applies configuration sources in a defined order. Higher sources override lower ones.

Lowest to highest priority:

Priority	Source	Location
1	Internal application.yml	Inside the ARender JAR
2	Internal application.properties	Inside the ARender JAR
3	External application.yml	Next to the JAR or mounted volume
4	External application.properties	Next to the JAR or mounted volume
5	Environment variables	OS env, Docker environment:, Kubernetes ConfigMap
6	JVM system properties	-D flags passed to java
7	Command-line arguments	--property=value passed after the JAR

A property defined at level 7 always wins over the same property defined at level 1.

.properties vs .yml precedence

When both formats exist at the same location, .properties takes precedence over .yml.

Example: both files define the same property:

application.yml

arender:
  server:
    rendition:
      hosts: http://broker-a:8761/

application.properties

arender.server.rendition.hosts=http://broker-b:8761/

Effective value: http://broker-b:8761/ — the .properties file wins because it has higher precedence than .yml at the same location.

This rule applies at every level of the configuration hierarchy.

External configuration locations

Spring Boot standalone

Place override files next to the ARender service JAR:

arender-document-service-broker-2026.0.0.jar
application.properties          # or .yml

Spring Boot detects and loads these files at startup without any additional flags.

Docker

Mount override files into the container at /home/arender/:

docker-compose.yml

services:
  service-broker:
    image: artifactory.arondor.cloud:5001/arender-document-service-broker
    volumes:
      - ./application.properties:/home/arender/application.properties

The container working directory is /home/arender/, so Spring Boot picks up the file automatically. The same approach works for all ARender service containers.

Kubernetes (Helm)

Use the config.file.extraConfig field in values.yaml to inject raw YAML into the generated application.yml ConfigMap:

values.yaml

broker:
  config:
    file:
      extraConfig: |
        arender:
          server:
            annotations:
              can:
                create: false

For simple key-value overrides, use environment variables instead. See Environment variables.

Resolution diagram

            ┌─────────────────────────────────┐
            │  7. Command-line arguments       │  ← highest priority
            ├─────────────────────────────────┤
            │  6. JVM -D system properties     │
            ├─────────────────────────────────┤
            │  5. Environment variables        │
            ├─────────────────────────────────┤
            │  3-4. External config files      │
            ├─────────────────────────────────┤
            │  1-2. ARender JAR base config    │  ← lowest priority
            └─────────────────────────────────┘

Practical guidelines

• Do not edit files inside the ARender JAR. Use external files or environment variables.
• Use environment variables for deployment-specific values (hostnames, ports, credentials). They sit above file-based configuration in the hierarchy.
• Use JVM -D flags sparingly, typically for debugging or one-off test runs.

Related pages

• Environment variables: naming conventions and per-service prefixes
• Docker Compose: container-based deployment