Getting "Whitelabel Error Page" when opening "/actuator/mappings" - spring-boot

Question

I'm new to spring-cloud, so i'm using a video tutorial, so to read exposed endpoints i tried to open http://localhost:8000/actuator/mappings but it didn't work for me but the /health url gave me the following result:
Here's the written code in the client side:
#RefreshScope
#RestController
class MessageRestController {
#Value("${message}")
private String message;
#RequestMapping("/message")
String getMessage() {
return this.message;
}
}
pom.xml:
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.spring.cloud.reservation</groupId>
<artifactId>reservation-service</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>reservation-service</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.SR1</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-rest</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${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>
Here's the client project structure:
bootstrap.properties:
spring.application.name=reservation-service
spring.cloud.config.uri=http://localhost:8888
When executing the Post on the /refresh gives me : Error Not Found
curl -d {} http://localhost:8000/actuator/refresh
spring-boot-actuator jar version = 2.1.3

Answer 1

Default management.endpoints.web.exposure.include, info, health
As actuator/health and actuator/info are provided by default you will get the information
management.endpoints.web.exposure.include = * //will allow all endpoints
to be exposed
management.endpoints.web.exposure.include=health,info # Endpoint IDs that should be included or '*' for all.
management.endpoints.web.exposure.exclude= # Endpoint IDs that should be excluded or '*' for all.
management.endpoints.web.base-path=/actuator # Base path for Web endpoints. Relative to server.servlet.context-path or management.server.servlet.context-path if management.server.port is configured.
management.endpoints.web.path-mapping= # Mapping between endpoint IDs and the path that should expose them.
Securing Endpoint
management.endpoint.health.roles= # Roles used to determine whether or not a user is authorized to be shown details. When empty, all authenticated users are authorized. //for health
management.endpoint.health.show-details=always,never # When to show full health details.
Enable/Disable endpoints
management.endpoint.(endpointName).enabled=true # Whether to enable the health endpoint.
e.g. management.endpoint.health.enabled=true

Answer 2

Spring boot 2.x :: only health and info is exposed by default, In order to expose other actuator endpoint either mention the endpoint name or add following line to expose all endpoints.
management.endpoints.web.exposure.include: '*'

Answer 3

Starting from Spring boot 2.x, all actuator endpoints are disabled except for few non sensitive endpoints like /health and /info by default.
You can enable them using property management.endpoints.web.exposure.include=*
Please refer here for more details.

Answer 4

you have to do post, e.g
curl -X POST xxx.yyy.zzz:8080/actuator/refresh