Spring Boot actuator

endpoints.default.web.enabled=true

compile('org.springframework.boot:spring-boot-starter-actuator')

/*
 * Copyright 2012-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.boot.actuate.system;

import java.io.File;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.boot.actuate.health.AbstractHealthIndicator;
import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.boot.actuate.health.Status;

/**
 * A {@link HealthIndicator} that checks available disk space and reports a status of
 * {@link Status#DOWN} when it drops below a configurable threshold.
 *
 * @author Mattias Severson
 * @author Andy Wilkinson
 * @since 2.0.0
 */
public class DiskSpaceHealthIndicator extends AbstractHealthIndicator {

    private static final Log logger = LogFactory.getLog(DiskSpaceHealthIndicator.class);

    private final File path;

    private final long threshold;

    /**
     * Create a new {@code DiskSpaceHealthIndicator} instance.
     * @param path the Path used to compute the available disk space
     * @param threshold the minimum disk space that should be available (in bytes)
     */
    public DiskSpaceHealthIndicator(File path, long threshold) {
        this.path = path;
        this.threshold = threshold;
    }

    @Override
    protected void doHealthCheck(Health.Builder builder) throws Exception {
        long diskFreeInBytes = this.path.getUsableSpace();
        if (diskFreeInBytes >= this.threshold) {
            builder.up();
        }
        else {
            logger.warn(String.format(
                    "Free disk space below threshold. "
                            + "Available: %d bytes (threshold: %d bytes)",
                    diskFreeInBytes, this.threshold));
            builder.down();
        }
        builder.withDetail("total", this.path.getTotalSpace())
                .withDetail("free", diskFreeInBytes)
                .withDetail("threshold", this.threshold);
    }

}

/*
 * Copyright 2012-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.boot.actuate.health;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.boot.actuate.health.Health.Builder;

/**
 * Base {@link HealthIndicator} implementations that encapsulates creation of
 * {@link Health} instance and error handling.
 * <p>
 * This implementation is only suitable if an {@link Exception} raised from
 * {@link #doHealthCheck(org.springframework.boot.actuate.health.Health.Builder)} should
 * create a {@link Status#DOWN} health status.
 *
 * @author Christian Dupuis
 * @since 1.1.0
 */
public abstract class AbstractHealthIndicator implements HealthIndicator {

    private final Log logger = LogFactory.getLog(getClass());

    @Override
    public final Health health() {
        Health.Builder builder = new Health.Builder();
        try {
            doHealthCheck(builder);
        }
        catch (Exception ex) {
            this.logger.warn("Health check failed", ex);
            builder.down(ex);
        }
        return builder.build();
    }

    /**
     * Actual health check logic.
     * @param builder the {@link Builder} to report health status and details
     * @throws Exception any {@link Exception} that should create a {@link Status#DOWN}
     * system status.
     */
    protected abstract void doHealthCheck(Health.Builder builder) throws Exception;

}

package org.springframework.boot.actuate.health;

/**
 * Strategy interface used to provide an indication of application health.
 *
 * @author Dave Syer
 * @see ApplicationHealthIndicator
 */
@FunctionalInterface
public interface HealthIndicator {

    /**
     * Return an indication of health.
     * @return the health for
     */
    Health health();

}

// 20180102140749
// http://127.0.0.1:8080/actuator

{
  "_links": {
    "self": {
      "href": "http://127.0.0.1:8080/actuator",
      "templated": false
    },
    "health": {
      "href": "http://127.0.0.1:8080/actuator/health",
      "templated": false
    },
    "info": {
      "href": "http://127.0.0.1:8080/actuator/info",
      "templated": false
    }
  }
}