This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Cloud Consul 4.1.2! |
Quick Start
This quick start walks through using Spring Cloud Consul for Service Discovery and Distributed Configuration.
First, run Consul Agent on your machine. Then you can access it and use it as a Service Registry and Configuration source with Spring Cloud Consul.
Discovery Client Usage
To use these features in an application, you can build it as a Spring Boot application that depends on spring-cloud-consul-core
.
The most convenient way to add the dependency is with a Spring Boot starter: org.springframework.cloud:spring-cloud-starter-consul-discovery
.
We recommend using dependency management and spring-boot-starter-parent
.
The following example shows a typical Maven configuration:
<project>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>{spring-boot-version}</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
The following example shows a typical Gradle setup:
plugins {
id 'org.springframework.boot' version ${spring-boot-version}
id 'io.spring.dependency-management' version ${spring-dependency-management-version}
id 'java'
}
repositories {
mavenCentral()
}
dependencies {
implementation 'org.springframework.cloud:spring-cloud-starter-consul-discovery'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
}
dependencyManagement {
imports {
mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
}
}
Now you can create a standard Spring Boot application, such as the following HTTP server:
@SpringBootApplication @RestController public class Application { @GetMapping("/") public String home() { return "Hello World!"; } public static void main(String[] args) { SpringApplication.run(Application.class, args); } }
When this HTTP server runs, it connects to Consul Agent running at the default local 8500 port.
To modify the startup behavior, you can change the location of Consul Agent by using application.properties
, as shown in the following example:
spring: cloud: consul: host: localhost port: 8500
You can now use DiscoveryClient
, @LoadBalanced RestTemplate
, or @LoadBalanced WebClient.Builder
to retrieve services and instances data from Consul, as shown in the following example:
@Autowired
private DiscoveryClient discoveryClient;
public String serviceUrl() {
List<ServiceInstance> list = discoveryClient.getInstances("STORES");
if (list != null && list.size() > 0 ) {
return list.get(0).getUri().toString();
}
return null;
}
Distributed Configuration Usage
To use these features in an application, you can build it as a Spring Boot application that depends on spring-cloud-consul-core
and spring-cloud-consul-config
.
The most convenient way to add the dependency is with a Spring Boot starter: org.springframework.cloud:spring-cloud-starter-consul-config
.
We recommend using dependency management and spring-boot-starter-parent
.
The following example shows a typical Maven configuration:
<project>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>{spring-boot-version}</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
The following example shows a typical Gradle setup:
plugins {
id 'org.springframework.boot' version ${spring-boot-version}
id 'io.spring.dependency-management' version ${spring-dependency-management-version}
id 'java'
}
repositories {
mavenCentral()
}
dependencies {
implementation 'org.springframework.cloud:spring-cloud-starter-consul-config'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
}
dependencyManagement {
imports {
mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
}
}
Now you can create a standard Spring Boot application, such as the following HTTP server:
@SpringBootApplication @RestController public class Application { @GetMapping("/") public String home() { return "Hello World!"; } public static void main(String[] args) { SpringApplication.run(Application.class, args); } }
The application retrieves configuration data from Consul.
If you use Spring Cloud Consul Config, you need to set the spring.config.import property in order to bind to Consul.
You can read more about it in the Spring Boot Config Data Import section.
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