Configuring your Red Hat build of Quarkus applications by using a YAML file

You can manage your application’s settings in a single configuration file. Additionally, you can define configuration profiles to group related settings for different environments, such as development, testing, or production. This way, you can easily switch between profiles and apply environment-specific properties without altering your main configuration file.

By default, Quarkus reads properties from the application.properties file located in the src/main/resources directory. If, instead, you prefer to configure and manage application properties in an application.yaml file, add the quarkus-config-yaml dependency to your project’s pom.xml file. For more information, see Adding YAML configuration support.

Red Hat build of Quarkus also supports MicroProfile Config, which you can use to load your application’s configuration from various sources. By using the MicroProfile Config specification from the Eclipse MicroProfile project, you can inject configuration properties into your application and access them by using methods defined in your code.

Quarkus can read application properties from different origins, including:

Red Hat build of Quarkus supports YAML configuration files through the SmallRye Config implementation of Eclipse MicroProfile Config. You can add the Quarkus Config YAML extension and use the YAML configuration file over the properties file for configuration. Quarkus supports the use of application.yml and application.yaml as the name of the YAML file.

The YAML configuration file takes precedence over the application.properties file. To avoid errors, you can delete the application.properties file and use only one type of configuration file.

You can combine property references and text strings into property expressions and use them as values in your Red Hat build of Quarkus configuration.

Like variables, property expressions substitute configuration values dynamically, helping you avoid hard-coded values.

You can reference a property defined in one configuration source from another source.

Red Hat build of Quarkus resolves a property expression when it reads the configuration property:

If a property expression cannot be resolved and does not include a default value, Red Hat build of Quarkus throws a NoSuchElementException.

mach: 3
x:
  factor: 2.23694

display:
  mach: ${mach}
  unit:
    name: "mph"
    factor: ${x.factor}

To configure your application properties at runtime, add your application.yaml file to the config directory.

When config/application.yaml and src/main/resources/application.yaml share properties, values from config/application.yaml override those in src/main/resources/application.yaml.

Ensure that the config/application.yaml file is in the root of the working directory relative to the Quarkus application runner, as outlined in the following example:

├── config
│    └── application.yaml
├── my-app-runner

Structured formats such as YAML only support a subset of the possible configuration namespace. The following procedure shows how to resolve a conflict between two configuration properties, quarkus.http.cors and quarkus.http.cors.methods, where one property is the prefix of another.