[BAEL-3313] spring-cloud/spring-cloud-gateway | Writing custom Spring Cloud Gateway Filters (#8182)

* updated dependency management in spring-cloud-gateway pom.xml * * renamed org package to com * renamed spring.cloud package to springcloudgateway * deleted SpringContextIntegrationTest, as per BAEL-14304 * updated spring Junit test to jupiter * separated introduction-application properties from application.yml, fixing launch error due to file not found exception * Added Service to use as Proxied Service * Added global filters and debug logs for article * fixed error in properties source, plus added GatewayFilter Factories * implemented Modify Request example * implemented Modify Response example * implemented Chain Request example * Added Tests: * Live Test for gateway * Integration tests for services Fixed small issues * renamed tests that were not following BDD naming
2019-11-22 23:42:56 -03:00
parent b1971384e2
commit 7ee5019f7e
31 changed files with 805 additions and 83 deletions
@@ -0,0 +1,15 @@
+package com.baeldung.springcloudgateway.customfilters;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.PropertySource;
+
+@SpringBootApplication
+@PropertySource("classpath:customfilters-global-application.properties")
+public class CustomFiltersGatewayApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(CustomFiltersGatewayApplication.class, args);
+    }
+
+}
@@ -0,0 +1,16 @@
+package com.baeldung.springcloudgateway.customfilters.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Configuration
+public class WebClientConfig {
+
+    @Bean
+    WebClient client() {
+        return WebClient.builder()
+            .build();
+    }
+
+}
@@ -0,0 +1,90 @@
+package com.baeldung.springcloudgateway.customfilters.filters.factories;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale.LanguageRange;
+import java.util.stream.Collectors;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cloud.gateway.filter.GatewayFilter;
+import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.client.WebClient;
+
+import reactor.core.publisher.Mono;
+
+@Component
+public class ChainRequestGatewayFilterFactory extends AbstractGatewayFilterFactory<ChainRequestGatewayFilterFactory.Config> {
+
+    final Logger logger = LoggerFactory.getLogger(ChainRequestGatewayFilterFactory.class);
+
+    private final WebClient client;
+
+    public ChainRequestGatewayFilterFactory(WebClient client) {
+        super(Config.class);
+        this.client = client;
+    }
+
+    @Override
+    public List<String> shortcutFieldOrder() {
+        return Arrays.asList("endpoint", "defaultLanguage");
+    }
+
+    @Override
+    public GatewayFilter apply(Config config) {
+        return (exchange, chain) -> {
+            return client.get()
+                .uri(config.getEndpoint())
+                .exchange()
+                .flatMap(response -> {
+                    return (response.statusCode()
+                        .is2xxSuccessful()) ? response.bodyToMono(String.class) : Mono.just(config.getDefaultLanguage());
+                })
+                .map(LanguageRange::parse)
+                .map(range -> {
+                    exchange.getRequest()
+                        .mutate()
+                        .headers(h -> h.setAcceptLanguage(range))
+                        .build();
+
+                    String allOutgoingRequestLanguages = exchange.getRequest()
+                        .getHeaders()
+                        .getAcceptLanguage()
+                        .stream()
+                        .map(r -> r.getRange())
+                        .collect(Collectors.joining(","));
+
+                    logger.info("Chain Request output - Request contains Accept-Language header: " + allOutgoingRequestLanguages);
+
+                    return exchange;
+                })
+                .flatMap(chain::filter);
+
+        };
+    }
+
+    public static class Config {
+        private String endpoint;
+        private String defaultLanguage;
+
+        public Config() {
+        }
+
+        public String getEndpoint() {
+            return endpoint;
+        }
+
+        public void setEndpoint(String endpoint) {
+            this.endpoint = endpoint;
+        }
+
+        public String getDefaultLanguage() {
+            return defaultLanguage;
+        }
+
+        public void setDefaultLanguage(String defaultLanguage) {
+            this.defaultLanguage = defaultLanguage;
+        }
+    }
+}
@@ -0,0 +1,85 @@
+package com.baeldung.springcloudgateway.customfilters.filters.factories;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cloud.gateway.filter.GatewayFilter;
+import org.springframework.cloud.gateway.filter.OrderedGatewayFilter;
+import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
+import org.springframework.stereotype.Component;
+
+import reactor.core.publisher.Mono;
+
+@Component
+public class LoggingGatewayFilterFactory extends AbstractGatewayFilterFactory<LoggingGatewayFilterFactory.Config> {
+
+    final Logger logger = LoggerFactory.getLogger(LoggingGatewayFilterFactory.class);
+
+    public static final String BASE_MSG = "baseMessage";
+    public static final String PRE_LOGGER = "preLogger";
+    public static final String POST_LOGGER = "postLogger";
+
+    public LoggingGatewayFilterFactory() {
+        super(Config.class);
+    }
+
+    @Override
+    public List<String> shortcutFieldOrder() {
+        return Arrays.asList(BASE_MSG, PRE_LOGGER, POST_LOGGER);
+    }
+
+    @Override
+    public GatewayFilter apply(Config config) {
+        return new OrderedGatewayFilter((exchange, chain) -> {
+            if (config.isPreLogger())
+                logger.info("Pre GatewayFilter logging: " + config.getBaseMessage());
+            return chain.filter(exchange)
+                .then(Mono.fromRunnable(() -> {
+                    if (config.isPostLogger())
+                        logger.info("Post GatewayFilter logging: " + config.getBaseMessage());
+                }));
+        }, -2);
+    }
+
+    public static class Config {
+        private String baseMessage;
+        private boolean preLogger;
+        private boolean postLogger;
+
+        public Config() {
+        };
+
+        public Config(String baseMessage, boolean preLogger, boolean postLogger) {
+            super();
+            this.baseMessage = baseMessage;
+            this.preLogger = preLogger;
+            this.postLogger = postLogger;
+        }
+
+        public String getBaseMessage() {
+            return this.baseMessage;
+        }
+
+        public boolean isPreLogger() {
+            return preLogger;
+        }
+
+        public boolean isPostLogger() {
+            return postLogger;
+        }
+
+        public void setBaseMessage(String baseMessage) {
+            this.baseMessage = baseMessage;
+        }
+
+        public void setPreLogger(boolean preLogger) {
+            this.preLogger = preLogger;
+        }
+
+        public void setPostLogger(boolean postLogger) {
+            this.postLogger = postLogger;
+        }
+    }
+}
@@ -0,0 +1,78 @@
+package com.baeldung.springcloudgateway.customfilters.filters.factories;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Locale;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cloud.gateway.filter.GatewayFilter;
+import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
+import org.springframework.stereotype.Component;
+
+@Component
+public class ModifyRequestGatewayFilterFactory extends AbstractGatewayFilterFactory<ModifyRequestGatewayFilterFactory.Config> {
+
+    final Logger logger = LoggerFactory.getLogger(ModifyRequestGatewayFilterFactory.class);
+
+    public ModifyRequestGatewayFilterFactory() {
+        super(Config.class);
+    }
+
+    @Override
+    public List<String> shortcutFieldOrder() {
+        return Arrays.asList("defaultLocale");
+    }
+
+    @Override
+    public GatewayFilter apply(Config config) {
+        return (exchange, chain) -> {
+            if (exchange.getRequest()
+                .getHeaders()
+                .getAcceptLanguage()
+                .isEmpty()) {
+
+                String queryParamLocale = exchange.getRequest()
+                    .getQueryParams()
+                    .getFirst("locale");
+
+                Locale requestLocale = Optional.ofNullable(queryParamLocale)
+                    .map(l -> Locale.forLanguageTag(l))
+                    .orElse(config.getDefaultLocale());
+
+                exchange.getRequest()
+                    .mutate()
+                    .headers(h -> h.setAcceptLanguageAsLocales(Collections.singletonList(requestLocale)))
+                    .build();
+            }
+
+            String allOutgoingRequestLanguages = exchange.getRequest()
+                .getHeaders()
+                .getAcceptLanguage()
+                .stream()
+                .map(range -> range.getRange())
+                .collect(Collectors.joining(","));
+
+            logger.info("Modify Request output - Request contains Accept-Language header: " + allOutgoingRequestLanguages);
+            return chain.filter(exchange);
+        };
+    }
+
+    public static class Config {
+        private Locale defaultLocale;
+
+        public Config() {
+        }
+
+        public Locale getDefaultLocale() {
+            return defaultLocale;
+        }
+
+        public void setDefaultLocale(String defaultLocale) {
+            this.defaultLocale = Locale.forLanguageTag(defaultLocale);
+        };
+    }
+}
@@ -0,0 +1,48 @@
+package com.baeldung.springcloudgateway.customfilters.filters.factories;
+
+import java.util.Optional;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cloud.gateway.filter.GatewayFilter;
+import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.stereotype.Component;
+
+import reactor.core.publisher.Mono;
+
+@Component
+public class ModifyResponseGatewayFilterFactory extends AbstractGatewayFilterFactory<ModifyResponseGatewayFilterFactory.Config> {
+
+    final Logger logger = LoggerFactory.getLogger(ModifyResponseGatewayFilterFactory.class);
+
+    public ModifyResponseGatewayFilterFactory() {
+        super(Config.class);
+    }
+
+    @Override
+    public GatewayFilter apply(Config config) {
+        return (exchange, chain) -> {
+            return chain.filter(exchange)
+                .then(Mono.fromRunnable(() -> {
+                    ServerHttpResponse response = exchange.getResponse();
+
+                    Optional.ofNullable(exchange.getRequest()
+                        .getQueryParams()
+                        .getFirst("locale"))
+                        .ifPresent(qp -> {
+                            String responseContentLanguage = response.getHeaders()
+                                .getContentLanguage()
+                                .getLanguage();
+
+                            response.getHeaders()
+                                .add("Bael-Custom-Language-Header", responseContentLanguage);
+                            logger.info("Added custom header to Response");
+                        });
+                }));
+        };
+    }
+
+    public static class Config {
+    }
+}
@@ -0,0 +1,39 @@
+package com.baeldung.springcloudgateway.customfilters.filters.global;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cloud.gateway.filter.GlobalFilter;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.annotation.Order;
+
+import reactor.core.publisher.Mono;
+
+@Configuration
+public class LoggingGlobalFiltersConfigurations {
+
+    final Logger logger = LoggerFactory.getLogger(LoggingGlobalFiltersConfigurations.class);
+
+    @Bean
+    public GlobalFilter postGlobalFilter() {
+        return (exchange, chain) -> {
+            return chain.filter(exchange)
+                .then(Mono.fromRunnable(() -> {
+                    logger.info("Global Post Filter executed");
+                }));
+        };
+    }
+
+    @Bean
+    @Order(-1)
+    public GlobalFilter FirstPreLastPostGlobalFilter() {
+        return (exchange, chain) -> {
+            logger.info("First Pre Global Filter");
+            return chain.filter(exchange)
+                .then(Mono.fromRunnable(() -> {
+                    logger.info("Last Post Global Filter");
+                }));
+        };
+    }
+
+}
@@ -0,0 +1,28 @@
+package com.baeldung.springcloudgateway.customfilters.filters.global;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cloud.gateway.filter.GatewayFilterChain;
+import org.springframework.cloud.gateway.filter.GlobalFilter;
+import org.springframework.core.Ordered;
+import org.springframework.stereotype.Component;
+import org.springframework.web.server.ServerWebExchange;
+
+import reactor.core.publisher.Mono;
+
+@Component
+public class LoggingGlobalPreFilter implements GlobalFilter, Ordered {
+
+    final Logger logger = LoggerFactory.getLogger(LoggingGlobalPreFilter.class);
+
+    @Override
+    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
+        logger.info("Global Pre Filter executed");
+        return chain.filter(exchange);
+    }
+
+    @Override
+    public int getOrder() {
+        return 0;
+    }
+}
@@ -0,0 +1,28 @@
+package com.baeldung.springcloudgateway.customfilters.routes;
+
+import org.springframework.cloud.gateway.route.RouteLocator;
+import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
+import org.springframework.context.annotation.Bean;
+
+import com.baeldung.springcloudgateway.customfilters.filters.factories.LoggingGatewayFilterFactory;
+import com.baeldung.springcloudgateway.customfilters.filters.factories.LoggingGatewayFilterFactory.Config;
+
+/**
+ * Note: We want to keep this as an example of configuring a Route with a custom filter
+ *
+ * This corresponds with the properties configuration we have
+ */
+// @Configuration
+public class ServiceRouteConfiguration {
+
+    @Bean
+    public RouteLocator routes(RouteLocatorBuilder builder, LoggingGatewayFilterFactory loggingFactory) {
+
+        return builder.routes()
+            .route("service_route_java_config", r -> r.path("/service/**")
+                .filters(f -> f.rewritePath("/service(?<segment>/?.*)", "$\\{segment}")
+                    .filter(loggingFactory.apply(new Config("My Custom Message", true, true))))
+                .uri("http://localhost:8081"))
+            .build();
+    }
+}
@@ -0,0 +1,15 @@
+package com.baeldung.springcloudgateway.introduction;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.PropertySource;
+
+@SpringBootApplication
+@PropertySource("classpath:introduction-application.properties")
+public class IntroductionGatewayApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(IntroductionGatewayApplication.class, args);
+    }
+
+}