Spring启动，日志失败健康检查

Question

我们在 kubernetes 中使用 spring-boot(2.5.6)

我们使用的许多依赖项包括健康检查，例如 RedisHealthIndicator、CouchbaseHealthIndicator 等。

当这些健康检查之一失败并且整个应用程序健康状况失败时，kubernetes 会重新启动 pod。

然而，没有任何迹象表明失败的原因，Spring 不会记录运行状况检查失败，而是依靠运行状况检查本身来记录消息。 内置健康检查的情况并非如此。

所以从外面看，kubernetes 似乎“无缘无故”地杀死了这个 pod，我们必须假设这是健康检查

Spring 是否有一个“健康检查更改事件”，以便我可以记录哪个 bean 失败了？

或者以其他方式跟踪个人健康状况的“下降”状态

https:/ /github.com/spring-projects/spring-boot/issues/22632 这个问题是类似的，但他们明确声明他们不会记录失败

Answer 1

我自己也曾为此奋斗过一段时间。我不确定他们为什么对记录健康故障采取这种立场，但更糟糕的是当前的实现对于尝试注入这种功能非常不友好。

最后，我决定解决的问题是包装健康贡献者，以便我可以在他们报告未启动时记录消息。包装器本身非常简单：

public class LoggingHealthIndicator implements HealthIndicator {
    private static final Logger LOG = LoggerFactory.getLogger(LoggingHealthIndicator.class);
    private final String name;
    private final HealthIndicator delegate;

    public LoggingHealthIndicator(final String name, final HealthIndicator delegate) {
        this.name = name;
        this.delegate = delegate;
    }

    @Override
    public Health health() {
        final Health health = delegate.health();

        if (!Status.UP.equals(health.getStatus())) {
            if (health.getDetails() == null || health.getDetails().isEmpty()) {
                LOG.error("Health check '{}' {}", name, health.getStatus());
            }
            else {
                LOG.error("Health check '{}' {}: {}", name, health.getStatus(), health.getDetails());
            }
        }

        return health;
    }
}

您当然可以做任何您想做的事情；引发应用程序事件，进一步调整您记录的时间和内容等。随您喜欢。

就实际使用而言，这就是有点烦人的地方。它涉及用我们自己的增强版本替换 HealthContributorRegistry。

    /**
     * Replicated from {@link org.springframework.boot.actuate.autoconfigure.health.HealthEndpointConfiguration}.
     *
     * Note that we lose the {@link org.springframework.boot.actuate.autoconfigure.health.HealthEndpointConfiguration.AdaptedReactiveHealthContributors},
     * since it is private. Technically its private to the package-scoped class it's a child of, so we lose twice really.
     */
    @Bean
    @SuppressWarnings("JavadocReference")
    public HealthContributorRegistry healthContributorRegistry(final Map<String, HealthContributor> contributors, final HealthEndpointGroups groups) {
        return new LoggingHealthContributorRegistry(contributors, groups.getNames());
    }    

public class LoggingHealthContributorRegistry extends AutoConfiguredHealthContributorRegistryCopy {

    private static HealthContributor loggingContributor(final Entry<String, HealthContributor> entry) {
        return loggingContributor(entry.getKey(), entry.getValue());
    }

    private static HealthContributor loggingContributor(final String name, final HealthContributor contributor) {
        if (contributor instanceof HealthIndicator){
            return new LoggingHealthIndicator(name, (HealthIndicator)contributor);
        }
        return contributor;
    }

    public LoggingHealthContributorRegistry(Map<String, HealthContributor> contributors, Collection<String> groupNames) {
        // The constructor does not use `registerContributor` on the input map entries
        super(contributors.entrySet().stream().collect(Collectors.toMap(Entry::getKey, LoggingHealthContributorRegistry::loggingContributor)),
              groupNames);
    }

    @Override
    public void registerContributor(String name, HealthContributor contributor) {
        super.registerContributor(name, loggingContributor(name, contributor));
    }
}

关于 AutoConfiguredHealthContributorRegistryCopy 的说明：它实际上只是 AutoConfiguredHealthContributorRegistry 类的副本，该类恰好是包范围的，因此不可继承（除非您不介意玩包）游戏）

Answer 2

这是我的决定，仅记录 /actuator/health 的 UP 状态

    import com.fasterxml.jackson.core.JsonProcessingException;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.boot.actuate.endpoint.ApiVersion;
    import org.springframework.boot.actuate.endpoint.SecurityContext;
    import org.springframework.boot.actuate.endpoint.web.WebEndpointResponse;
    import org.springframework.boot.actuate.endpoint.web.WebServerNamespace;
    import org.springframework.boot.actuate.endpoint.web.annotation.EndpointWebExtension;
    import org.springframework.boot.actuate.health.HealthComponent;
    import org.springframework.boot.actuate.health.HealthEndpoint;
    import org.springframework.boot.actuate.health.HealthEndpointGroups;
    import org.springframework.boot.actuate.health.ReactiveHealthContributorRegistry;
    import org.springframework.boot.actuate.health.ReactiveHealthEndpointWebExtension;
    import org.springframework.boot.actuate.health.Status;
    import org.springframework.stereotype.Component;
    import reactor.core.publisher.Mono;
    
    @Slf4j
    @Component
    @EndpointWebExtension(endpoint = HealthEndpoint.class)
    public class LoggingReactiveHealthEndpointWebExtension extends ReactiveHealthEndpointWebExtension {
    
      private final ObjectMapper objectMapper;
    
    
      public LoggingReactiveHealthEndpointWebExtension(ReactiveHealthContributorRegistry registry,
          HealthEndpointGroups groups, ObjectMapper objectMapper) {
        super(registry, groups, null);
        this.objectMapper = objectMapper;
      }
    
      @Override
      public Mono<WebEndpointResponse<? extends HealthComponent>> health(ApiVersion apiVersion,
          WebServerNamespace serverNamespace, SecurityContext securityContext, boolean showAll,
          String... path) {
        Mono<WebEndpointResponse<? extends HealthComponent>> health = super.health(apiVersion,
            serverNamespace, securityContext, showAll, path);
    
        return health.doOnNext(it -> {
          if (it.getBody().getStatus() != Status.UP) {
            log.error("Health status: {}, {}", it.getBody().getStatus(), mapToString(it.getBody()));
          }
        });
      }
    
      public <T> String mapToString(T object) {
        try {
          return objectMapper.writeValueAsString(object);
        } catch (JsonProcessingException e) {
          log.error("Can not convert Object: {} to String", object.getClass().getName(), e);
          return null;
        }
      }
    }