springboot2增加diskspace指标

/**
 * External configuration properties for {@link DiskSpaceHealthIndicator}.
 *
 * @author Andy Wilkinson
 * @since 1.2.0
 */
@ConfigurationProperties(prefix = "management.health.diskspace")
public class DiskSpaceHealthIndicatorProperties {

    private static final int MEGABYTES = 1024 * 1024;

    private static final int DEFAULT_THRESHOLD = 10 * MEGABYTES;

    /**
     * Path used to compute the available disk space.
     */
    private File path = new File(".");

    /**
     * Minimum disk space, in bytes, that should be available.
     */
    private long threshold = DEFAULT_THRESHOLD;

    public File getPath() {
        return this.path;
    }

    public void setPath(File path) {
        Assert.isTrue(path.exists(), () -> "Path '" + path + "' does not exist");
        Assert.isTrue(path.canRead(), () -> "Path '" + path + "' cannot be read");
        this.path = path;
    }

    public long getThreshold() {
        return this.threshold;
    }

    public void setThreshold(long threshold) {
        Assert.isTrue(threshold >= 0, "threshold must be greater than 0");
        this.threshold = threshold;
    }

}

/**
 * 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) {
        super("DiskSpace health check failed");
        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);
    }

}

@Component
public class DiskMetrics implements MeterBinder {

    private File rootFilePath;

    public DiskMetrics() {
        this.rootFilePath = new File(".");
    }

    @Override
    public void bindTo(MeterRegistry registry) {
        Gauge.builder("diskspace.total", rootFilePath, c -> c.getTotalSpace())
                .register(registry);
        Gauge.builder("diskspace.free", rootFilePath, c -> c.getFreeSpace())
                .register(registry);
        Gauge.builder("diskspace.usage", rootFilePath, c -> {
            long totalDiskSpace = rootFilePath.getTotalSpace();
            if (totalDiskSpace == 0) {
                return 0.0;
            }

            long usedDiskSpace = totalDiskSpace - rootFilePath.getFreeSpace();
            return Double.valueOf(usedDiskSpace) / totalDiskSpace * 100;
        })
                .register(registry);
    }
}