oparl-service/oparl-server/src/main/java/de/twomartens/oparlservice/actuator/AbstractHealthCheck.java

package de.twomartens.oparlservice.actuator;

import de.twomartens.oparlservice.interceptors.RequestTypeInterceptor;
import de.twomartens.oparlservice.interceptors.TraceIdInterceptor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;

@Slf4j
public abstract class AbstractHealthCheck implements HealthIndicator {

  private static final String DEFAULT_HOST = "localhost";
  private static final String HEALTH_KEY_ENDPOINT = "endpoint";

  private final String endpoint;

  private final TraceIdInterceptor traceIdInterceptor;

  private final RequestTypeInterceptor requestTypeInterceptor;

  private final int port;

  public AbstractHealthCheck(int port,
      TraceIdInterceptor traceIdInterceptor,
      RequestTypeInterceptor requestTypeInterceptor) {
    this.traceIdInterceptor = traceIdInterceptor;
    this.requestTypeInterceptor = requestTypeInterceptor;
    this.port = port;
    this.endpoint = mkEndpoint();
  }

  @Override
  public Health health() {
    requestTypeInterceptor.markAsHealthCheck();
    traceIdInterceptor.createNewTraceId();
    Health result;
    try {
      if (isEndpointAvailable()) {
        result = Health.up().withDetail(HEALTH_KEY_ENDPOINT, getEndpoint()).build();
      } else {
        result = Health.down().withDetail(HEALTH_KEY_ENDPOINT, getEndpoint()).build();
      }
    } catch (Exception e) {
      result = Health.down().withDetail(HEALTH_KEY_ENDPOINT, getEndpoint()).withException(e).build();
    }
    log.info("health check invoked for '{}' with status '{}'", getMethodName(), result.getStatus());
    return result;
  }

  String getHost() {
    return DEFAULT_HOST;
  }

  int getPort() {
    return this.port;
  }

  String getEndpoint() {
    return this.endpoint;
  }

  abstract boolean isEndpointAvailable();

  abstract String getMethodName();

  abstract String mkEndpoint();

}