Gateway 聚合swagger文档

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在微服务架构下，通常每个微服务都会使用 Swagger 来管理我们的接口文档，当微服务越来越多，接口查找管理无形中要浪费我们不少时间，因此，我们需要把其它系统的 Swagger 文档聚合到 Gateway ,方便我们统一查看接口文档。

1. 核心实现

1.1 OMS 端实现

1.1.1 swagger配置文件

@Data
@ConfigurationProperties("swagger")
public class SwaggerProperties {
    /**
     * 是否开启swagger
     */
    private Boolean enabled;
    /**
     * swagger会解析的包路径
     **/
    private String basePackage = "";
    /**
     * swagger会解析的url规则
     **/
    private List<String> basePath = new ArrayList<>();
    /**
     * 在basePath基础上需要排除的url规则
     **/
    private List<String> excludePath = new ArrayList<>();
    /**
     * 标题
     **/
    private String title = "";
    /**
     * 描述
     **/
    private String description = "";
    /**
     * 版本
     **/
    private String version = "";
    /**
     * 许可证
     **/
    private String license = "";
    /**
     * 许可证URL
     **/
    private String licenseUrl = "";
    /**
     * 服务条款URL
     **/
    private String termsOfServiceUrl = "";

    /**
     * host信息
     **/
    private String host = "";
    /**
     * 联系人信息
     */
    private Contact contact = new Contact();
    /**
     * 全局统一鉴权配置
     **/
    private Authorization authorization = new Authorization();

    @Data
    @NoArgsConstructor
    public static class Contact {

        /**
         * 联系人
         **/
        private String name = "";
        /**
         * 联系人url
         **/
        private String url = "";
        /**
         * 联系人email
         **/
        private String email = "";

    }

    @Data
    @NoArgsConstructor
    public static class Authorization {

        /**
         * 鉴权策略ID，需要和SecurityReferences ID保持一致
         */
        private String name = "";

        /**
         * 需要开启鉴权URL的正则
         */
        private String authRegex = "^.*$";

        /**
         * 鉴权作用域列表
         */
        private List<AuthorizationScope> authorizationScopeList = new ArrayList<>();

        private List<String> tokenUrlList = new ArrayList<>();
    }

    @Data
    @NoArgsConstructor
    public static class AuthorizationScope {

        /**
         * 作用域名称
         */
        private String scope = "";

        /**
         * 作用域描述
         */
        private String description = "";

    }
}

1.1.2 swagger 自动配置类

@Configuration
@EnableSwagger2
@EnableAutoConfiguration
@ConditionalOnProperty(name = "swagger.enabled", matchIfMissing = true)
public class SwaggerAutoConfiguration {

    /**
     *     默认的排除路径，排除Spring Boot默认的错误处理路径和端点
     */
    private static final List<String> DEFAULT_EXCLUDE_PATH = Arrays.asList("/error","/actuator/**");
    private static final String BASE_PATH = "/**";

    @Bean
    @ConditionalOnMissingBean
    public SwaggerProperties swaggerProperties() {
        return new SwaggerProperties();
    }

    @Bean
    public Docket api(SwaggerProperties swaggerProperties) {
        // base-path处理
        if (swaggerProperties.getBasePath().isEmpty()) {
            swaggerProperties.getBasePath().add(BASE_PATH);
        }
        //noinspection unchecked
        List<Predicate<String>> basePath = new ArrayList();
        swaggerProperties.getBasePath().forEach(path -> basePath.add(PathSelectors.ant(path)));

        // exclude-path处理
        if (swaggerProperties.getExcludePath().isEmpty()) {
            swaggerProperties.getExcludePath().addAll(DEFAULT_EXCLUDE_PATH);
        }
        List<Predicate<String>> excludePath = new ArrayList<>();
        swaggerProperties.getExcludePath().forEach(path -> excludePath.add(PathSelectors.ant(path)));

        //noinspection Guava
        return new Docket(DocumentationType.SWAGGER_2)
            .host(swaggerProperties.getHost())
            .apiInfo(apiInfo(swaggerProperties)).select()
            .apis(RequestHandlerSelectors.basePackage(swaggerProperties.getBasePackage()))
            .paths(Predicates.and(Predicates.not(Predicates.or(excludePath)), Predicates.or(basePath)))
            .build()
            .securitySchemes(Collections.singletonList(securitySchema()))
            .securityContexts(Collections.singletonList(securityContext()))
            .pathMapping("/");
    }

    /**
     * 配置默认的全局鉴权策略的开关，通过正则表达式进行匹配；默认匹配所有URL
     *
     * @return
     */
    private SecurityContext securityContext() {
        return SecurityContext.builder()
            .securityReferences(defaultAuth())
            .forPaths(PathSelectors.regex(swaggerProperties().getAuthorization().getAuthRegex()))
            .build();
    }

    /**
     * 默认的全局鉴权策略
     *
     * @return
     */
    private List<SecurityReference> defaultAuth() {
        ArrayList<AuthorizationScope> authorizationScopeList = new ArrayList<>();
        swaggerProperties().getAuthorization().getAuthorizationScopeList().forEach(authorizationScope -> authorizationScopeList.add(new AuthorizationScope(authorizationScope.getScope(), authorizationScope.getDescription())));
        AuthorizationScope[] authorizationScopes = new AuthorizationScope[authorizationScopeList.size()];
        return Collections.singletonList(SecurityReference.builder()
            .reference(swaggerProperties().getAuthorization().getName())
            .scopes(authorizationScopeList.toArray(authorizationScopes))
            .build());
    }


    private OAuth securitySchema() {
        ArrayList<AuthorizationScope> authorizationScopeList = new ArrayList<>();
        swaggerProperties().getAuthorization().getAuthorizationScopeList().forEach(authorizationScope -> authorizationScopeList.add(new AuthorizationScope(authorizationScope.getScope(), authorizationScope.getDescription())));
        ArrayList<GrantType> grantTypes = new ArrayList<>();
        swaggerProperties().getAuthorization().getTokenUrlList().forEach(tokenUrl -> grantTypes.add(new ResourceOwnerPasswordCredentialsGrant(tokenUrl)));
        return new OAuth(swaggerProperties().getAuthorization().getName(), authorizationScopeList, grantTypes);
    }

    private ApiInfo apiInfo(SwaggerProperties swaggerProperties) {
        return new ApiInfoBuilder()
            .title(swaggerProperties.getTitle())
            .description(swaggerProperties.getDescription())
            .license(swaggerProperties.getLicense())
            .licenseUrl(swaggerProperties.getLicenseUrl())
            .termsOfServiceUrl(swaggerProperties.getTermsOfServiceUrl())
            .contact(new Contact(swaggerProperties.getContact().getName(), swaggerProperties.getContact().getUrl(), swaggerProperties.getContact().getEmail()))
            .version(swaggerProperties.getVersion())
            .build();
    }

}

1.1.3 设置允许跨域

如果不设置允许跨域，则 Gateway 无法跨域调用 OMS 的 Swagger 文档，因此，需要设置 swagger 接口允许跨域。

package com.ftl.oms.config;

@Configuration
public class GlobalCorsConfig {

    @Bean
    public CorsFilter corsFilter() {
        //1.添加CORS配置信息
        CorsConfiguration config = new CorsConfiguration();
        //放行哪些原始域
        config.addAllowedOrigin("*");
        //是否发送Cookie信息
        config.setAllowCredentials(true);
        //放行哪些原始域(请求方式)
        config.addAllowedMethod("*");
        //放行哪些原始域(头部信息)
        config.addAllowedHeader("*");
        //暴露哪些头部信息（因为跨域访问默认不能获取全部头部信息）
        config.addExposedHeader("Access-Control-Allow-*");

        //2.添加映射路径
        UrlBasedCorsConfigurationSource configSource = new UrlBasedCorsConfigurationSource();
        configSource.registerCorsConfiguration("/api/**", config);
        configSource.registerCorsConfiguration("/v2/api-docs", config);

        //3.返回新的CorsFilter.
        return new CorsFilter(configSource);
    }
}

1.2 GATEWAY 端实现

1.2.1 swagger配置文件


@Data
@Component
@ConfigurationProperties("swagger")
public class SwaggerProperties {

    /**
     * 资源名称
     */
    private List<Resource> resources;

    /**
     * 是否开启swagger
     */
    private Boolean enabled;
    /**
     * swagger会解析的包路径
     **/
    private String basePackage = "";
    /**
     * swagger会解析的url规则
     **/
    private List<String> basePath = new ArrayList<>();
    /**
     * 在basePath基础上需要排除的url规则
     **/
    private List<String> excludePath = new ArrayList<>();
    /**
     * 标题
     **/
    private String title = "";
    /**
     * 描述
     **/
    private String description = "";
    /**
     * 版本
     **/
    private String version = "";
    /**
     * 许可证
     **/
    private String license = "";
    /**
     * 许可证URL
     **/
    private String licenseUrl = "";
    /**
     * 服务条款URL
     **/
    private String termsOfServiceUrl = "";

    /**
     * host信息
     **/
    private String host = "";
    /**
     * 联系人信息
     */
    private Contact contact = new Contact();
    /**
     * 全局统一鉴权配置
     **/
    private Authorization authorization = new Authorization();

    @Data
    @NoArgsConstructor
    public static class Contact {

        /**
         * 联系人
         **/
        private String name = "";
        /**
         * 联系人url
         **/
        private String url = "";
        /**
         * 联系人email
         **/
        private String email = "";

    }

    @Data
    @NoArgsConstructor
    public static class Authorization {

        /**
         * 鉴权策略ID，需要和SecurityReferences ID保持一致
         */
        private String name = "";

        /**
         * 需要开启鉴权URL的正则
         */
        private String authRegex = "^.*$";

        /**
         * 鉴权作用域列表
         */
        private List<AuthorizationScope> authorizationScopeList = new ArrayList<>();

        private List<String> tokenUrlList = new ArrayList<>();
    }

    @Data
    @NoArgsConstructor
    public static class AuthorizationScope {

        /**
         * 作用域名称
         */
        private String scope = "";

        /**
         * 作用域描述
         */
        private String description = "";

    }



    @Data
    @NoArgsConstructor
    public static class Resource {

        /**
         * 资源名称
         */
        private String name;

        /**
         * 转发路径
         */
        private String url;

        /**
         * 文档版本
         */
        private String swaggerVersion;
    }
}

注：GATEWAY 端比 OMS 端的配置文件多出了 private List<Resource> resources; ，这个主要功能是从配置文件中得到 OMS 的 swagger 接口文档接口，从而聚合其它服务的文档。

1.2.2 swagger 自动配置类

 

@Configuration
@EnableSwagger2
@EnableAutoConfiguration
@ConditionalOnProperty(name = "swagger.enabled", matchIfMissing = true)
public class SwaggerAutoConfiguration {

    /**
     *     默认的排除路径，排除Spring Boot默认的错误处理路径和端点
     */
    private static final List<String> DEFAULT_EXCLUDE_PATH = Arrays.asList("/error","/actuator/**");
    private static final String BASE_PATH = "/**";

    @Bean
    @ConditionalOnMissingBean
    public SwaggerProperties swaggerProperties() {
        return new SwaggerProperties();
    }

    @Bean
    public Docket api(SwaggerProperties swaggerProperties) {
        // base-path处理
        if (swaggerProperties.getBasePath().isEmpty()) {
            swaggerProperties.getBasePath().add(BASE_PATH);
        }
        //noinspection unchecked
        List<Predicate<String>> basePath = new ArrayList();
        swaggerProperties.getBasePath().forEach(path -> basePath.add(PathSelectors.ant(path)));

        // exclude-path处理
        if (swaggerProperties.getExcludePath().isEmpty()) {
            swaggerProperties.getExcludePath().addAll(DEFAULT_EXCLUDE_PATH);
        }
        List<Predicate<String>> excludePath = new ArrayList<>();
        swaggerProperties.getExcludePath().forEach(path -> excludePath.add(PathSelectors.ant(path)));

        //noinspection Guava
        return new Docket(DocumentationType.SWAGGER_2)
            .host(swaggerProperties.getHost())
            .apiInfo(apiInfo(swaggerProperties)).select()
            .apis(RequestHandlerSelectors.basePackage(swaggerProperties.getBasePackage()))
            .paths(Predicates.and(Predicates.not(Predicates.or(excludePath)), Predicates.or(basePath)))
            .build()
            .securitySchemes(Collections.singletonList(securitySchema()))
            .securityContexts(Collections.singletonList(securityContext()))
            .pathMapping("/");
    }

    /**
     * 配置默认的全局鉴权策略的开关，通过正则表达式进行匹配；默认匹配所有URL
     *
     * @return
     */
    private SecurityContext securityContext() {
        return SecurityContext.builder()
            .securityReferences(defaultAuth())
            .forPaths(PathSelectors.regex(swaggerProperties().getAuthorization().getAuthRegex()))
            .build();
    }

    /**
     * 默认的全局鉴权策略
     *
     * @return
     */
    private List<SecurityReference> defaultAuth() {
        ArrayList<AuthorizationScope> authorizationScopeList = new ArrayList<>();
        swaggerProperties().getAuthorization().getAuthorizationScopeList().forEach(authorizationScope -> authorizationScopeList.add(new AuthorizationScope(authorizationScope.getScope(), authorizationScope.getDescription())));
        AuthorizationScope[] authorizationScopes = new AuthorizationScope[authorizationScopeList.size()];
        return Collections.singletonList(SecurityReference.builder()
            .reference(swaggerProperties().getAuthorization().getName())
            .scopes(authorizationScopeList.toArray(authorizationScopes))
            .build());
    }


    private OAuth securitySchema() {
        ArrayList<AuthorizationScope> authorizationScopeList = new ArrayList<>();
        swaggerProperties().getAuthorization().getAuthorizationScopeList().forEach(authorizationScope -> authorizationScopeList.add(new AuthorizationScope(authorizationScope.getScope(), authorizationScope.getDescription())));
        ArrayList<GrantType> grantTypes = new ArrayList<>();
        swaggerProperties().getAuthorization().getTokenUrlList().forEach(tokenUrl -> grantTypes.add(new ResourceOwnerPasswordCredentialsGrant(tokenUrl)));
        return new OAuth(swaggerProperties().getAuthorization().getName(), authorizationScopeList, grantTypes);
    }

    private ApiInfo apiInfo(SwaggerProperties swaggerProperties) {
        return new ApiInfoBuilder()
            .title(swaggerProperties.getTitle())
            .description(swaggerProperties.getDescription())
            .license(swaggerProperties.getLicense())
            .licenseUrl(swaggerProperties.getLicenseUrl())
            .termsOfServiceUrl(swaggerProperties.getTermsOfServiceUrl())
            .contact(new Contact(swaggerProperties.getContact().getName(), swaggerProperties.getContact().getUrl(), swaggerProperties.getContact().getEmail()))
            .version(swaggerProperties.getVersion())
            .build();
    }

}

1.2.3 swagger 资源配置信息

这个类主要是用来暴露 swagger 相关资源的接口，允许浏览器加载所对应的资源文件


@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)));
    }
}

1.2.4 swagger 聚合配置

这个类主要负责的功能是将其它系统的文档聚合到 gateway，重写 SwaggerResourcesProvider#get() 方法，从 yml 配置文件中，得到其它系统的 swagger 文档信息，然后gateway 转发到不同的系统的 swagger。


@Component
@Primary
@AllArgsConstructor
public class SwaggerProviderConfiguration implements SwaggerResourcesProvider {


    private static final String API_URI = "/v2/api-docs";

    @Autowired
    private SwaggerProperties swaggerProperties;


    @Override
    public List<SwaggerResource> get() {
        List<SwaggerProperties.Resource> resourcesPropertes = swaggerProperties.getResources();
        if (resourcesPropertes.isEmpty()) {
            return Lists.newArrayList();
        }

        // 从yml配置文件中加载其它系统的swagger资源
        List<SwaggerResource> resources = new ArrayList<>();

        resourcesPropertes.forEach(resource -> {
            resources.add(this.swaggerResource(resource.getName(), resource.getUrl() + API_URI, resource.getSwaggerVersion()));
        });


        return resources;
    }

    private SwaggerResource swaggerResource(String name, String url, String version) {
        SwaggerResource swaggerResource = new SwaggerResource();
        swaggerResource.setName(name);
        swaggerResource.setLocation(url);
        swaggerResource.setSwaggerVersion(version);
        return swaggerResource;
    }
}