de.codecentric.spring.boot.chaos.monkey.watcher.outgoing.ChaosMonkeyRestTemplateWatcher Maven / Gradle / Ivy

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/*
 * Copyright 2021-2022 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
 *
 *     https://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 de.codecentric.spring.boot.chaos.monkey.watcher.outgoing;

import de.codecentric.spring.boot.chaos.monkey.component.ChaosMonkeyRequestScope;
import de.codecentric.spring.boot.chaos.monkey.component.ChaosTarget;
import de.codecentric.spring.boot.chaos.monkey.configuration.AssaultProperties;
import de.codecentric.spring.boot.chaos.monkey.configuration.WatcherProperties;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpRequest;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.AbstractClientHttpResponse;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.lang.Nullable;
import org.springframework.util.StreamUtils;

/** @author Marcel Becker */
public class ChaosMonkeyRestTemplateWatcher implements ClientHttpRequestInterceptor {

    private final WatcherProperties watcherProperties;
    private final ChaosMonkeyRequestScope chaosMonkeyRequestScope;
    private final AssaultProperties assaultProperties;

    public ChaosMonkeyRestTemplateWatcher(final ChaosMonkeyRequestScope chaosMonkeyRequestScope, final WatcherProperties watcherProperties,
            AssaultProperties assaultProperties) {
        this.chaosMonkeyRequestScope = chaosMonkeyRequestScope;
        this.watcherProperties = watcherProperties;
        this.assaultProperties = assaultProperties;
    }

    @Override
    public ClientHttpResponse intercept(final HttpRequest httpRequest, byte[] bytes, ClientHttpRequestExecution clientHttpRequestExecution)
            throws IOException {
        ClientHttpResponse response = clientHttpRequestExecution.execute(httpRequest, bytes);
        if (watcherProperties.isRestTemplate()) {
            try {
                chaosMonkeyRequestScope.callChaosMonkey(ChaosTarget.REST_TEMPLATE, httpRequest.getURI().toString());
            } catch (final Exception exception) {
                try {
                    if (exception.getClass().equals(assaultProperties.getException().getExceptionClass())) {
                        response = new ErrorResponse();
                    } else {
                        throw exception;
                    }
                } catch (ClassNotFoundException e) {
                    throw new RuntimeException(e);
                }
            }
        }
        return response;
    }

    static class ErrorResponse extends AbstractClientHttpResponse {

        static final String ERROR_TEXT = "This error is generated by Chaos Monkey for Spring Boot";
        static final String ERROR_BODY = "{\"error\": \"This is a Chaos Monkey for Spring Boot generated failure\"}";

        private static final Logger Logger = LoggerFactory.getLogger(ErrorResponse.class);

        @Nullable
        private InputStream responseStream;

        @Override
        public int getRawStatusCode() {
            return HttpStatus.INTERNAL_SERVER_ERROR.value();
        }

        @Override
        public String getStatusText() {
            return ERROR_TEXT;
        }

        @Override
        public void close() {
            try {
                if (this.responseStream == null) {
                    getBody();
                }
                StreamUtils.drain(this.responseStream);
                this.responseStream.close();
            } catch (Exception ex) {
                Logger.debug("Exception while closing the error response", ex);
                // ignore {@see
                // #org.springframework.http.client.SimpleClientHttpResponse.close()}
            }
        }

        @Override
        public InputStream getBody() {
            responseStream = new ByteArrayInputStream(ERROR_BODY.getBytes(StandardCharsets.UTF_8));
            return responseStream;
        }

        @Override
        public HttpHeaders getHeaders() {
            return new HttpHeaders();
        }
    }
}