Quarkus - Configuring Your Application
Hardcoded values in your code are a no go (even if we all did it at some point ;-)). In this guide, we learn how to configure your application.
Prerequisites
To complete this guide, you need:
-
between 5 and 10 minutes
-
an IDE
-
JDK 1.8+ installed with
JAVA_HOME
configured appropriately -
Apache Maven 3.6.2+
Solution
We recommend that you follow the instructions in the next sections and create the application step by step. However, you can go right to the completed example.
Clone the Git repository: git clone https://github.com/quarkusio/quarkus-quickstarts.git
, or download an archive.
The solution is located in the config-quickstart
directory.
Creating the Maven project
First, we need a new project. Create a new project with the following command:
mvn io.quarkus:quarkus-maven-plugin:1.12.0.Final:create \
-DprojectGroupId=org.acme \
-DprojectArtifactId=config-quickstart \
-DclassName="org.acme.config.GreetingResource" \
-Dpath="/greeting"
cd config-quickstart
It generates:
-
the Maven structure
-
a landing page accessible on
http://localhost:8080
-
example
Dockerfile
files for bothnative
andjvm
modes -
the application configuration file
-
an
org.acme.config.GreetingResource
resource -
an associated test
Create the configuration
By default, Quarkus reads configuration properties from several sources.
For the purpose of this guide, we will use an application configuration file located in src/main/resources/application.properties
.
Edit the file with the following content:
# Your configuration properties
greeting.message = hello
greeting.name = quarkus
Injecting configuration properties
Quarkus uses MicroProfile Config annotations to inject the configuration properties in the application.
@ConfigProperty(name = "greeting.message") (1)
String message;
1 | You can use @Inject @ConfigProperty or just @ConfigProperty .
The @Inject annotation is not necessary for members annotated with @ConfigProperty .
This behavior differs from MicroProfile Config. |
If the application attempts to inject a configuration property that is not set, an error is thrown. So you can quickly know when your configuration is complete. |
Edit the org.acme.config.GreetingResource
, and introduce the following configuration properties:
@ConfigProperty(name = "greeting.message") (1)
String message;
@ConfigProperty(name = "greeting.suffix", defaultValue="!") (2)
String suffix;
@ConfigProperty(name = "greeting.name")
Optional<String> name; (3)
1 | If you do not provide a value for this property, the application startup fails with javax.enterprise.inject.spi.DeploymentException: No config value of type [class java.lang.String] exists for: greeting.message . |
2 | The default value is injected if the configuration does not provide a value for greeting.suffix . |
3 | This property is optional - an empty Optional is injected if the configuration does not provide a value for greeting.name . |
Now, modify the hello
method to use the injected properties:
@GET
@Produces(MediaType.TEXT_PLAIN)
public String hello() {
return message + " " + name.orElse("world") + suffix;
}
Once set, check the application with:
$ curl http://localhost:8080/greeting
hello quarkus!
As an alternative to injecting multiple related configuration values, you can also use the @io.quarkus.arc.config.ConfigProperties annotation to group these properties together.
See the Configuration Reference Guide for more information.
|
Update the test
We also need to update the functional test to reflect the changes made to the endpoint.
Edit the src/test/java/org/acme/config/GreetingResourceTest.java
file and change the content of the testHelloEndpoint
method to:
package org.acme.config;
import io.quarkus.test.junit.QuarkusTest;
import org.junit.jupiter.api.Test;
import static io.restassured.RestAssured.given;
import static org.hamcrest.CoreMatchers.is;
@QuarkusTest
public class GreetingResourceTest {
@Test
public void testHelloEndpoint() {
given()
.when().get("/greeting")
.then()
.statusCode(200)
.body(is("hello quarkus!")); // Modified line
}
}
Package and run the application
Run the application with: ./mvnw compile quarkus:dev
.
Open your browser to http://localhost:8080/greeting.
Changing the configuration file is immediately reflected.
You can add the greeting.suffix
, remove the other properties, change the values, etc.
As usual, the application can be packaged using ./mvnw clean package
and executed using the target/quarkus-app/quarkus-run.jar
file.
You can also generate the native executable with ./mvnw clean package -Pnative
.
Programmatically access the configuration
You can also access the configuration programmatically. It can be handy to achieve dynamic lookup, or retrieve configured values from classes that are neither CDI beans or JAX-RS resources.
You can access the configuration programmatically using org.eclipse.microprofile.config.ConfigProvider.getConfig()
such as in:
String databaseName = ConfigProvider.getConfig().getValue("database.name", String.class);
Optional<String> maybeDatabaseName = ConfigProvider.getConfig().getOptionalValue("database.name", String.class);
Configuration Profiles
Quarkus supports the notion of configuration profiles. These allow you to have multiple configuration values in the same file and select between them via a profile name.
The syntax for this is %{profile}.config.key=value
. For example if I have the following:
quarkus.http.port=9090
%dev.quarkus.http.port=8181
Then the Quarkus HTTP port will be 9090, unless the dev
profile is active, in which case it will be 8181.
See the Configuration Reference Guide for more information about configuration profiles.
Configuring Quarkus
Quarkus itself is configured via the same mechanism as your application. Quarkus reserves the quarkus.
namespace
for its own configuration. For example to configure the HTTP server port you can set quarkus.http.port
in
application.properties
. All the Quarkus configuration properties are documented and searchable.
As mentioned above, properties prefixed with In the previous examples using |
Quarkus does much of its configuration and bootstrap at build time and some configuration properties are read and used during the build. These properties are fixed at build time and it’s not possible to change them at runtime. You always need to repackage your application in order to reflect changes of such properties.
The properties fixed at build time are marked with a lock icon () in the list of all configuration options. |
However, some extensions do define properties overridable at runtime. A canonical example is the database URL, username and password which is only known specifically in your target environment.
-
System properties
-
Environment variables
-
An environment file named
.env
placed in the current working directory -
A configuration file placed in
$PWD/config/application.properties
See the Configuration Reference Guide for more information.