Spring IO 2023 - Dynamic OpenAPIs with Spring Cloud Gateway

Spring IO 2023 - Dynamic OpenAPIs with Spring Cloud Gateway

• 1.
  Dynamic OpenAPIs with SpringCloud Gateway Iván López @ilopmar
• 2.
  @ilopmar Iván López Who amI? ● Iván López (@ilopmar) ● JVM Developer ● Staff Software Engineer at VMware ● @MadridGUG Coordinator ● Speaker: GeeCon, Codemotion, Devoxx, SpringOne, RigaDevDays, CommitConf, Spring IO,... 🇪🇸🇮🇹🇬🇧🇦🇹🇨🇦🇧🇪🇨🇿🇺🇦🇩🇰🇸🇪🇺🇸🇷🇺🇪🇪🇱🇻🇭🇷🇵🇱🇹🇷🇷🇴🇧🇬
• 3.
  OpenAPI
• 4.
  @ilopmar Iván López OpenAPI Specification ●Old Swagger Specification ● API description format for REST APIs ● Endpoints, operations, parameters, authentication,... ● Programming language agnostic ● YAML or JSON
• 5.
  @ilopmar Iván López Swagger ● Setof opensource tools build around OpenApi Spec ● Swagger Editor ● Swagger UI ● Swagger Codegen ● Swagger Core, Parser,...
• 6.
  @ilopmar Iván López Why useOpenAPI? ● Standard widely used ● Huge userbase ● Stable implementation ● Swagger Codegen to generate server stub and client libraries! ● Integrations with many languages, libraries and frameworks
• 7.
  Spring Cloud Gateway
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  @ilopmar Iván López What isan API Gateway? ● API proxy between an API Client and API Server ● Single entry point for the backend API and services ● Cross-cuttings concerns: security, rate-limiting, monitoring, logging, metrics,...
• 9.
  @ilopmar Iván López Spring CloudGateway ● API Gateway for the Spring Ecosystem ● Built on top Spring Boot, WebFlux and Reactor ● Dynamic routing ● Route matching: Path, Method, Header, Host,... ● Filters ● Rate Limiting, Circuit Breaker ● Path Rewriting
• 10.
  @ilopmar Iván López Spring CloudGateway Basics ● Route, Predicate and Filter ● Route Predicates: Cookie, Header, Host, Method, Path,... ● Gateway Factories: Add/Remove Request/Response Header/Parameter, Rewrite path ● Global and custom filters ● YAML configuration & Programmatic API
• 11.
  @ilopmar Iván López Spring CloudGateway examples spring: cloud: gateway: routes: - id: method_route uri: https://example.org predicates: - Method=GET,POST spring: cloud: gateway: routes: - id: add_request_header_route uri: https://example.org filters: - AddRequestHeader=X-Foo, some-value spring: cloud: gateway: routes: - id: rewritepath_route uri: https://example.org predicates: - Path=/foo/** filters: - RewritePath=/foo/?(?<segment>.*), /${segment}
• 12.
  The problem
• 13.
  “I just wantto expose the OpenAPI of my application”
• 14.
  @ilopmar Iván López Current status ●Spring Cloud Gateway in front of all different services ● All services expose OpenAPI ● API First? – Code -> OpenAPI – OpenAPI -> Code ● Internal endpoints vs Public endpoints ● Manual configuration in SCG
• 15.
  @ilopmar Iván López Requirements ● Exposeproduct Public OpenAPI in Gateway ● Aggregate endpoints from different services ● Public endpoints defined on every service ● Optionally rewrite some endpoints ● Expose only public schemas and not all of them ● Rewrite and group tags ● Update Public OpenAPI and routing must be dynamic
• 16.
  @ilopmar Iván López My approach ●I did a 1 week spike ● We use SCG OSS ● The feature is available in SCG Commercial: Only Tanzu Application Service and Kubernetes ● We deploy on K8S but wanted to keep everything agnostic: local development, on-premise,... ● Libraries to read/write OpenAPI specifications ● SCG Programmatic API
• 17.
  Solution
• 18.
  @ilopmar Iván López Every servicedefines... ● Which endpoint is made public paths: /pipelines: post: x-vmw-public: true summary: Create a new pipeline definition description: Given a pipeline, it creates an execution graph and prepares it to be run
• 19.
  @ilopmar Iván López Every servicedefines... ● How an endpoint is rewritten paths: /reports: get: x-vmw-public: true x-vmw-rewrite: /vulnerabilities/reports summary: Get all reports, optionally filtered by artifact version description: It returns a collection of report metadata...
• 20.
  @ilopmar Iván López Every servicedefines... ● How tags are rewritten tags: - name: products description: Using these endpoints you can manage the products... x-vmw-rewrite: inventory - name: artifacts description: Using these endpoints you can manage the artifacts... x-vmw-rewrite: inventory - name: artifact-versions description: Using these endpoints you can manage the artifact versions... x-vmw-rewrite: inventory - name: inventory description: Using these endpoints you can see the products, artifacts and artifact versions and their relationships in your organization inventory
• 21.
  @ilopmar Iván López Every servicedefines... ● How tags are rewritten tags: - name: products description: Using these endpoints you can manage the products... x-vmw-rewrite: inventory - name: artifacts description: Using these endpoints you can manage the artifacts... x-vmw-rewrite: inventory - name: artifact-versions description: Using these endpoints you can manage the artifact versions... x-vmw-rewrite: inventory - name: inventory description: Using these endpoints you can see the products, artifacts and artifact versions and their relationships in your organization inventory
• 22.
  @ilopmar Iván López OpenAPI creation ●Gateway polls services every 5 minutes ● Filter, transform and combine all the OpenAPI specs ● Creates Public OpenAPI specification on the fly
• 23.
  @ilopmar Iván López Expose OpenAPI @GetMapping(value= "/v1/api.yml", produces = APPLICATION_X_YAML) public ResponseEntity<String> v1() { return openApiService.generateOpenApi() .map(ResponseEntity::ok) .orElseGet(() -> ResponseEntity.notFound().build()); }
• 24.
  @ilopmar Iván López Spring CloudGateway routes @Bean @RefreshScope public RouteLocator routeLocator(RouteLocatorBuilder routeLocatorBuilder, RouteService routeService) { RouteLocatorBuilder.Builder routeLocator = routeLocatorBuilder.routes(); List<GatewayRoute> gatewayRoutes = routeService.findGatewayRoutes(); for (GatewayRoute gatewayRoute : gatewayRoutes) { routeLocator.route(gatewayRoute.routeId(), r -> r .order(gatewayRoute.order()) .path(gatewayRoute.gatewayPath()) .and().method(gatewayRoute.openApiRoute().method()) .filters(gatewayFilterSpec -> gatewayFilterSpec.rewritePath(gatewayRoute.regexp(), gatewayRoute.rewritePath()) ) .uri(gatewayRoute.openApiRoute().uri())); } return routeLocator.build(); } ● Routes refreshed dynamically
• 25.
  @ilopmar Iván López ● Routesrefreshed dynamically Spring Cloud Gateway routes @Bean @RefreshScope public RouteLocator routeLocator(RouteLocatorBuilder routeLocatorBuilder, RouteService routeService) { RouteLocatorBuilder.Builder routeLocator = routeLocatorBuilder.routes(); List<GatewayRoute> gatewayRoutes = routeService.findGatewayRoutes(); for (GatewayRoute gatewayRoute : gatewayRoutes) { routeLocator.route(gatewayRoute.routeId(), r -> r .order(gatewayRoute.order()) .path(gatewayRoute.gatewayPath()) .and().method(gatewayRoute.openApiRoute().method()) .filters(gatewayFilterSpec -> gatewayFilterSpec.rewritePath(gatewayRoute.regexp(), gatewayRoute.rewritePath()) ) .uri(gatewayRoute.openApiRoute().uri())); } return routeLocator.build(); }
• 26.
  @ilopmar Iván López Gateway Routes publicList<GatewayRoute> findGatewayRoutes() { return openApiService.findOpenApiRoutes() .stream() .map(RouteConverter::convertOpenApiRouteToGatewayRoute) .filter(Optional::isPresent) .map(Optional::get) .toList(); }
• 27.
  @ilopmar Iván López Example: Routeconversion (I) OpenApiRoute[ originalPath=/v1/reports newPath=/v1/vulnerabilities/reports method=GET uri=https://vulnerability-service.xxxxxxxxxxxxx ] GatewayRoute[ routeId=GET__/v1/vulnerabilities/reports gatewayPath=/v1/vulnerabilities/reports regexp=/v1/vulnerabilities/reports rewritePath=/v1/reports order=0 ]
• 28.
  @ilopmar Iván López Example: Routeconversion (II) OpenApiRoute[ originalPath=/v1/target-platforms/{target_platform_id} newPath=/v1/tp/{target_platform_id} method=GET uri=https://provisioning-service.xxxxxxxxxxxxx ] GatewayRoute[ routeId=GET__/v1/tp/{target_platform_id} gatewateyPath=/v1/tp/?* regexp=/v1/tp/(?<id1>.*) rewritePath=/v1/target-platforms/${id1} order=10 ]
• 29.
  @ilopmar Iván López Spring CloudGateway routes @Bean @RefreshScope public RouteLocator routeLocator(RouteLocatorBuilder routeLocatorBuilder, RouteService routeService) { RouteLocatorBuilder.Builder routeLocator = routeLocatorBuilder.routes(); List<GatewayRoute> openApiRoutes = routeService.findOpenApiRoutes(); for (GatewayRoute gatewayRoute : openApiRoutes) { routeLocator.route(gatewayRoute.routeId(), r -> r .order(gatewayRoute.order()) .path(gatewayRoute.gatewayPath()) .and().method(gatewayRoute.openApiRoute().method()) .filters(gatewayFilterSpec -> gatewayFilterSpec.rewritePath(gatewayRoute.regexp(), gatewayRoute.rewritePath()) ) .uri(gatewayRoute.openApiRoute().uri())); } return routeLocator.build(); } ● Routes refreshed dynamically
• 30.
  @ilopmar Iván López Example: GatewayRoutes (I) OpenApiRoute[ originalPath=/v1/reports newPath=/v1/vulnerabilities/reports method=GET uri=https://vulnerability-service... ] GatewayRoute[ routeId=GET__/v1/vulnerabilities/reports gatewateyPath=/v1/vulnerabilities/reports regexp=/v1/vulnerabilities/reports rewritePath=/v1/reports order=0 ] routeLocator.route("GET__/v1/vulnerabilities/reports", r -> r .order(0) .path("/v1/vulnerabilities/reports") .and().method("GET") .filters(s -> s.rewritePath("/v1/vulnerabilities/reports", "/v1/reports")) .uri("https://vulnerability-service.xxxxxxxxxxxxxxxxxx"));
• 31.
  @ilopmar Iván López Example: GatewayRoutes (II) OpenApiRoute[ originalPath=/v1/target-platforms/{target_platform_id} newPath=/v1/tp/{target_platform_id} method=GET uri=https://provisioning-service... ] GatewayRoute[ routeId=GET__/v1/tp/{target_platform_id} gatewateyPath=/v1/tp/?* regexp=/v1/tp/(?<id1>.*) rewritePath=/v1/target-platforms/${id1} order=10 ] routeLocator.route("GET__/v1/tp/{target_platform_id}", r -> r .order(10) .path("/v1/tp/?*") .and().method("GET") .filters(s -> s.rewritePath("/v1/tp/(?<id1>.*)", "/v1/target-platforms/${id1}")) .uri("https://provisioning-service.xxxxxxxxxxxxxxx"));
• 32.
  Demo
• 33.
  @ilopmar Iván López Summary Solved theproblem in one week +1 year in Production without problems Reuse existing OSS libraries Platform agnostic Spring Cloud Gateway is awesome Public and Dynamic OpenAPI
• 34.
  Thank you! Questions? Iván López @ilopmar [email protected] https:/ /github.com/ilopmar https:/ /bit.ly/springio-dynamic-apis