armeria-reactive-health-demo

Sample project to assist with line/armeria#4396

Getting Started

1. Install SDKMAN

curl -s "https://get.sdkman.io" | bash
source "$HOME/.sdkman/bin/sdkman-init.sh"

2. Install JDK17

sdk install java 17.0.4-tem

3. Run Application

./gradlew bootRun -Parmeria 

NOTE: bootRun without -Parmeria will exclude com.linecorp.armeria:armeria-spring-boot2-actuator-starter and use org.springframework.boot:spring-boot-starter-actuator instead.

4. Get application health

curl http://localhost:8080/actuator/health 

Description

When the com.linecorp.armeria:armeria-spring-boot2-actuator-starter dependency is included, the result from /actuator/health will always be HTTP 200 with the following response body:

{
  "scanAvailable": true
}

Log statements showing that CustomHealthIndicator#doHealthCheck was invoked will appear in app logs, however the log statements within the Mono<Health> returned from CustomHealthIndicator#doHealthCheck do not. This indicates that the Mono<Health> returned from CustomHealthIndicator#doHealthCheck never received a subscription and the custom health check logic was not invoked.

When excluding com.linecorp.armeria:armeria-spring-boot2-actuator-starter, the log statements within the Mono<Health> returned from CustomHealthIndicator#doHealthCheck appear in the app logs and a random, simulated health is returned from /actuator/health:

• When r.nextBoolean() == true:
  • Status Code: HTTP 200
  • Response Body: {"status": "UP"}
• When r.nextBoolean() == false:
  • Status Code: HTTP 503
  • Response Body: {"status": "DOWN"}