org.springframework.cloud.dataflow.server.controller.support.MetricStore.java Source code

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Here is the source code for org.springframework.cloud.dataflow.server.controller.support.MetricStore.java

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/*
 * Copyright 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.cloud.dataflow.server.controller.support;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.cloud.dataflow.rest.util.HttpClientConfigurer;
import org.springframework.cloud.dataflow.server.config.MetricsProperties;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.hateoas.PagedResources;
import org.springframework.hateoas.hal.Jackson2HalModule;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.util.StringUtils;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.util.UriComponentsBuilder;

/**
 * Store implementation returning metrics info from a collector application. Implemented
 * via hystrix command having a fallback to empty response.
 *
 * @author Janne Valkealahti
 */
public class MetricStore {

    private final static List<ApplicationsMetrics> EMPTY_RESPONSE = new ArrayList<ApplicationsMetrics>();

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

    private final RestTemplate restTemplate;

    private final MetricsProperties metricsProperties;

    private String collectorEndpoint;

    /**
     * Instantiates a new metric store.
     *
     * @param metricsProperties the metrics properties
     */
    public MetricStore(MetricsProperties metricsProperties) {
        this.metricsProperties = metricsProperties;
        ObjectMapper mapper = new ObjectMapper();
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        mapper.registerModule(new Jackson2HalModule());
        MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();
        messageConverter.setSupportedMediaTypes(MediaType.parseMediaTypes("application/hal+json"));
        messageConverter.setObjectMapper(mapper);
        restTemplate = new RestTemplate(Arrays.asList(messageConverter));
        final MetricsProperties.Collector collector = metricsProperties.getCollector();
        String baseURI = collector.getUri();
        if (StringUtils.hasText(baseURI)) {
            try {
                URI uri = new URI(baseURI);
                this.collectorEndpoint = UriComponentsBuilder.fromUri(uri).path("/collector/metrics/streams")
                        .build().toString();
                logger.info("Metrics Collector URI = [" + collectorEndpoint + "]");
                validateUsernamePassword(collector.getUsername(), collector.getPassword());
                if (StringUtils.hasText(collector.getUsername()) && StringUtils.hasText(collector.getPassword())) {
                    this.restTemplate.setRequestFactory(HttpClientConfigurer.create(new URI(collectorEndpoint))
                            .basicAuthCredentials(collector.getUsername(), collector.getPassword())
                            .skipTlsCertificateVerification(collector.isSkipSslValidation())
                            .buildClientHttpRequestFactory());
                    logger.debug("Configured basic security for Metrics Collector endpoint");
                } else {
                    logger.debug("Not configuring basic security for Metrics Collector endpoint");
                }
            } catch (URISyntaxException e) {
                logger.warn("Could not parse collector URI, stream metrics monitoring will not be available");
            }
        } else {
            logger.info("Metrics Collector URI = []");
        }
    }

    @HystrixCommand(fallbackMethod = "defaultMetrics")
    public List<ApplicationsMetrics> getMetrics() {
        List<ApplicationsMetrics> metrics = null;
        if (StringUtils.hasText(this.collectorEndpoint)) {
            try {
                PagedResources<ApplicationsMetrics> response = restTemplate
                        .exchange(this.collectorEndpoint, HttpMethod.GET, null,
                                new ParameterizedTypeReference<PagedResources<ApplicationsMetrics>>() {
                                })
                        .getBody();
                metrics = new ArrayList<>(response.getContent());
                if (logger.isDebugEnabled()) {
                    logger.debug("Metrics = " + metrics);
                }
            } catch (Exception e) {
                if (e instanceof HttpClientErrorException && e.getMessage().startsWith("401")) {
                    logger.warn(String.format(
                            "Failure while requesting metrics from url '%s': '%s'. "
                                    + "Unauthorized, please provide valid credentials.",
                            this.collectorEndpoint, e.getMessage()));
                } else {
                    logger.warn(String.format("Failure while requesting metrics from url '%s': %s",
                            this.collectorEndpoint, e.getMessage()));
                }
                if (logger.isDebugEnabled()) {
                    logger.debug("The metrics request failed with:", e);
                }
                throw e;
            }
        } else {
            metrics = defaultMetrics();
        }
        return metrics;
    }

    public List<ApplicationsMetrics> defaultMetrics() {
        return EMPTY_RESPONSE;
    }

    private void validateUsernamePassword(String userName, String password) {
        if (!StringUtils.isEmpty(password) && StringUtils.isEmpty(userName)) {
            logger.warn("A password may be specified only together with a username");
        }

        if (StringUtils.isEmpty(password) && !StringUtils.isEmpty(userName)) {
            logger.warn("A username may be specified only together with a password");
        }
    }
}