（5） Cloud integrated gateway gateway +swagger documentation tool

1. Preface

1.1 Why do I need to introduce a gateway ？

        Unified the entrance of each service , Users only need to know where the gateway is , In addition, it may also have authentication 、 monitor 、 cache 、 Request management 、 Static response processing and other functions . On the other hand , Flexible routing strategies can also be developed at the gateway layer . For some specific API, We need to set up a white list 、 Routing rules and other restrictions

        Be careful ！ This section contains only gateway The introduction of gateway , And integration Swagger Documentation tool , The deep usage of gateway is not included for the time being

1.2 Swagger file

        Document tool class , Docking and self-test are more convenient

2. Project iteration process

        No update here , Please refer to previous articles

3. Project access

3.1 newly build gateway Gateway module

        introduce pom.xml Related dependencies , Only major dependencies are introduced here

 .....       
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
            <version>3.1.1</version>
        </dependency>

        <!-- gateway -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-alibaba-sentinel-gateway</artifactId>
            <version>2021.0.1.0</version>
        </dependency>

<!--        &lt;!&ndash;   Support only SWAGGER Related dependencies , No UI  A choice  &ndash;&gt;-->
<!--        <dependency>-->
<!--            <groupId>com.github.xiaoymin</groupId>-->
<!--            <artifactId>knife4j-micro-spring-boot-starter</artifactId>-->
<!--            <version>3.0.3</version>-->
<!--        </dependency>-->

         <!--   Full version SWG rely on , belt UI  A choice   The gateway must be selected UI-->
         <dependency>
                <groupId>com.github.xiaoymin</groupId>
                <artifactId>knife4j-spring-boot-starter</artifactId>
                <version>3.0.3</version>
         </dependency>

 .....

        Create a new cross domain profile CorsConfig

@Configuration
public class CorsConfig {

    @Bean
    public CorsWebFilter corsFilter() {
        CorsConfiguration config = new CorsConfiguration();

        config.setAllowCredentials(true); //  allow cookies Cross domain 
        config.addAllowedOrigin("*");// # Allow requests to be submitted to this server URI,* That all are allowed , stay SpringMVC in , If set to *, It will be automatically converted to... In the current request header Origin
        config.addAllowedHeader("*");// # Allow access to header information ,* All 
        config.setMaxAge(18000L);//  Preview the cache time of the request （ second ）, In this period of time , For the same cross domain request, there will be no pre check 
        config.addAllowedMethod("OPTIONS");//  The type of method allowed to submit the request ,* That all are allowed 
        config.addAllowedMethod("HEAD");
        config.addAllowedMethod("GET");
        config.addAllowedMethod("PUT");
        config.addAllowedMethod("POST");
        config.addAllowedMethod("DELETE");
        config.addAllowedMethod("PATCH");

        UrlBasedCorsConfigurationSource source =
                new UrlBasedCorsConfigurationSource(new PathPatternParser());
        source.registerCorsConfiguration("/**", config);

        return new CorsWebFilter(source);
    }

}

        newly build swagger Get policy configuration file swaggerProvider

/**
 * @author zxg
 *  obtain Api-doc, namely SwaggerResources
 */
@Component
@Primary
public class SwaggerProvider implements SwaggerResourcesProvider {
    public static final String API_URI = "/v3/api-docs";
    private final RouteLocator routeLocator;
    private final GatewayProperties gatewayProperties;

    public SwaggerProvider(RouteLocator routeLocator, GatewayProperties gatewayProperties) {
        this.routeLocator = routeLocator;
        this.gatewayProperties = gatewayProperties;
    }

    @Override
    public List<SwaggerResource> get() {
        List<SwaggerResource> resources = new ArrayList<>();
        List<String> routes = new ArrayList<>();
        //  Take out gateway Of route
        routeLocator.getRoutes().subscribe(route -> routes.add(route.getId()));
        //  Combined with configured route- route (Path), and route Filter , Only get the... Described in the enumeration route node 
        gatewayProperties.getRoutes().stream().filter(routeDefinition -> routes.contains(routeDefinition.getId()))
                .forEach(routeDefinition -> routeDefinition.getPredicates().stream()
                        .filter(predicateDefinition -> ("Path").equalsIgnoreCase(predicateDefinition.getName()))
                        .forEach(predicateDefinition -> resources.add(swaggerResource(routeDefinition.getId(),
                                predicateDefinition.getArgs().get(NameUtils.GENERATED_NAME_PREFIX + "0")
                                        .replace("/**", API_URI)))
                        )
                );
        return resources;
    }

    private SwaggerResource swaggerResource(String name, String location) {
        SwaggerResource swaggerResource = new SwaggerResource();
        swaggerResource.setName(name);
        swaggerResource.setLocation(location);
        swaggerResource.setSwaggerVersion("3.0");
        return swaggerResource;
    }
}

        newly build swagger Intercept configuration

/**
 * @author zxg
 * Swagger According to X-Forwarded-Prefix This Header To get BasePath, Add it to the interface path and host middle , Only in this way can the interface test be carried out normally 
 */
@Component
public class SwaggerHeaderFilter extends AbstractGatewayFilterFactory {
    private static final String HEADER_NAME = "X-Forwarded-Prefix";

    @Override
    public GatewayFilter apply(Object config) {
        return (exchange, chain) -> {
            ServerHttpRequest request = exchange.getRequest();
            String path = request.getURI().getPath();
            if (!StringUtils.endsWithIgnoreCase(path, SwaggerProvider.API_URI)) {
                return chain.filter(exchange);
            }

            String basePath = path.substring(0, path.lastIndexOf(SwaggerProvider.API_URI));

            ServerHttpRequest newRequest = request.mutate().header(HEADER_NAME, basePath).build();
            ServerWebExchange newExchange = exchange.mutate().request(newRequest).build();
            return chain.filter(newExchange);
        };
    }

}

        newly build swagger Interface configuration

/**
 * @author zxg
 *  because Gateway There is no configuration in the SwaggerConfig, And running Swagger-ui You need to rely on some interfaces , So my idea is to establish corresponding swagger-resource Endpoint 
 */
@RestController
@RequestMapping("/swagger-resources")
public class SwaggerHandler {
    @Autowired(required = false)
    private SecurityConfiguration securityConfiguration;
    @Autowired(required = false)
    private UiConfiguration uiConfiguration;
    private final SwaggerResourcesProvider swaggerResources;

    @Autowired
    public SwaggerHandler(SwaggerResourcesProvider swaggerResources) {
        this.swaggerResources = swaggerResources;
    }


    @GetMapping("/configuration/security")
    public Mono<ResponseEntity<SecurityConfiguration>> securityConfiguration() {
        return Mono.just(new ResponseEntity<>(
                Optional.ofNullable(securityConfiguration).orElse(SecurityConfigurationBuilder.builder().build()), HttpStatus.OK));
    }

    @GetMapping("/configuration/ui")
    public Mono<ResponseEntity<UiConfiguration>> uiConfiguration() {
        return Mono.just(new ResponseEntity<>(
                Optional.ofNullable(uiConfiguration).orElse(UiConfigurationBuilder.builder().build()), HttpStatus.OK));
    }

    @GetMapping("")
    public Mono<ResponseEntity> swaggerResources() {
        return Mono.just((new ResponseEntity<>(swaggerResources.get(), HttpStatus.OK)));
    }
}

        stay application Configure service routing

        Only the routing part is posted here

spring:
  cloud:
    gateway:
      routes:
        - id: user-server
          uri: lb://user-server  #  use  LoadBalanceClient  Mode request , With  lb://  start , The last one is registered in nacos Service name on 
          predicates:
            - Path=/lb/user-server/**
          filters:
            - SwaggerHeaderFilter
            - StripPrefix=1

3.2 Other services

        To introduce the relevant pom.xml rely on

        <!--   Support only SWAGGER Related dependencies , No UI  A choice  -->
        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>knife4j-micro-spring-boot-starter</artifactId>
            <version>3.0.3</version>
        </dependency>

<!--        &lt;!&ndash;   Full version SWG rely on , belt UI  A choice  &ndash;&gt;-->
<!--        <dependency>-->
<!--            <groupId>com.github.xiaoymin</groupId>-->
<!--            <artifactId>knife4j-spring-boot-starter</artifactId>-->
<!--            <version>3.0.3</version>-->
<!--        </dependency>-->

        increase swagger The configuration file SwaggerConfig

/**
 * @author zxg
 */
@EnableOpenApi
@Configuration
public class SwaggerConfig {
    @Value("${spring.application.name}")
    private String applicationName;

    @Bean
    public Docket createRestApi(){
        return new Docket(DocumentationType.OAS_30)
                .apiInfo(apiInfo())
                .select()
                // To have @Api Annotated Controller Generate API file 
                .apis(RequestHandlerSelectors.withClassAnnotation(Api.class))
                .paths(PathSelectors.any())
                .build()
                .securitySchemes(unifiedAuth())
                .securityContexts(securityContexts())
                ;
    }

    private static List<SecurityScheme> unifiedAuth() {
        List<SecurityScheme> arrayList = new ArrayList();
        arrayList.add(new ApiKey("Authorization", "Authorization", "header"));
        return arrayList;
    }

    private List<SecurityContext> securityContexts() {
        List<SecurityContext> securityContexts=new ArrayList<>();
        securityContexts.add(
                SecurityContext.builder()
                        .securityReferences(defaultAuth())
                        .forPaths(PathSelectors.regex("^(?!auth).*$"))
                        .build());
        return securityContexts;
    }

    List<SecurityReference> defaultAuth() {
        AuthorizationScope authorizationScope = new AuthorizationScope("global", "accessEverything");
        AuthorizationScope[] authorizationScopes = new AuthorizationScope[1];
        authorizationScopes[0] = authorizationScope;
        List<SecurityReference> securityReferences=new ArrayList<>();
        securityReferences.add(new SecurityReference("Authorization", authorizationScopes));
        return securityReferences;
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title(applicationName + " Interface document ")
                .description(applicationName)
                .contact(new Contact("xueliman", "www.xueliman-iov.com", ""))
                .version("1.0")
                .build();
    }

    @Bean
    public static BeanPostProcessor springfoxHandlerProviderBeanPostProcessor() {
        return new BeanPostProcessor() {

            @Override
            public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
                if (bean instanceof WebMvcRequestHandlerProvider || bean instanceof WebFluxRequestHandlerProvider) {
                    customizeSpringfoxHandlerMappings(getHandlerMappings(bean));
                }
                return bean;
            }

            private <T extends RequestMappingInfoHandlerMapping> void customizeSpringfoxHandlerMappings(List<T> mappings) {
                List<T> copy = mappings.stream()
                        .filter(mapping -> mapping.getPatternParser() == null)
                        .collect(Collectors.toList());
                mappings.clear();
                mappings.addAll(copy);
            }

            @SuppressWarnings("unchecked")
            private List<RequestMappingInfoHandlerMapping> getHandlerMappings(Object bean) {
                try {
                    Field field = ReflectionUtils.findField(bean.getClass(), "handlerMappings");
                    field.setAccessible(true);
                    return (List<RequestMappingInfoHandlerMapping>) field.get(bean);
                } catch (IllegalArgumentException | IllegalAccessException e) {
                    throw new IllegalStateException(e);
                }
            }
        };
    }
}

3.3 Start project

Access gateway swagger Address , The contents are as follows

 

4. summary

        springcloud2021.x Version pair gateway The introduction of , And integration swagger file , Slightly different from the previous version , But not bad .

        The above content is a summary of personal learning process and obtained by referring to online materials , If there is something wrong in the text , Welcome to advise , No joy, no spray. .