Add API Gateway (#1572)

* add api-gateway

* move API contact and license to gateway

* remove unnecessary dependencies

* removed @Autowired` and added @requiredargsconstructor

* add README.md

api-gateway/README.md

@@ -0,0 +1,11 @@
+# API Gateway for VRO
+
+To support serving up APIs implemented in several languages (e.g., Java by the RRD Team and Python used by the CC Team),
+this API Gateway acts as a proxy to forward requests to the specified tenant API, as determined by the URI prefix.
+
+The URI prefixes are configured in `application.yml` -- under `spring.cloud.gateway.routes`.
+
+The Swagger UI destinations to tenant APIs are configured in `application.yml` -- under `springdoc.swagger-ui.urls`.
+
+The implementation is based on https://piotrminkowski.com/2020/02/20/microservices-api-documentation-with-springdoc-openapi/,
+which uses Spring Boot 3 and Spring Cloud Gateway.

api-gateway/build.gradle

@@ -0,0 +1,24 @@
+plugins {
+  id 'local.std.java.library-spring-conventions'
+  id 'local.java.container-spring-conventions'
+  id "com.google.osdetector" version "1.7.3"
+}
+
+dependencies {
+  // Spring Boot
+  implementation 'org.springframework.boot:spring-boot-starter-webflux'
+  implementation 'org.springframework.boot:spring-boot-starter-actuator'
+  implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
+
+  // Spring Cloud
+  implementation 'org.springframework.cloud:spring-cloud-starter-gateway:4.0.5'
+  if (osdetector.classifier == "osx-aarch_64") {
+    // Fix MacOS error: Unable to load io.netty.resolver.dns.macos.MacOSDnsServerAddressStreamProvider,
+    // which may result in incorrect DNS resolutions.
+    // Spring Cloud Gateway uses Netty
+    runtimeOnly("io.netty:netty-resolver-dns-native-macos:4.1.92.Final:${osdetector.classifier}")
+  }
+
+  // Swagger UI for WebFlux
+  implementation 'org.springdoc:springdoc-openapi-starter-webflux-ui:2.1.0'
+}

api-gateway/gradle.properties

@@ -0,0 +1 @@
+spring_boot_version=3.0.6

api-gateway/src/main/java/gov/va/vro/GatewayApplication.java

@@ -0,0 +1,18 @@
+package gov.va.vro;
+
+import io.swagger.v3.oas.annotations.OpenAPIDefinition;
+import io.swagger.v3.oas.annotations.info.Info;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.context.properties.ConfigurationPropertiesScan;
+
+@Slf4j
+@SpringBootApplication
+@ConfigurationPropertiesScan(basePackages = {"gov.va.vro"})
+public class GatewayApplication {
+  public static void main(String[] args) {
+    new SpringApplication(GatewayApplication.class).run(args);
+    log.info("\n-------- API Gateway Application Started ---------");
+  }
+}

api-gateway/src/main/java/gov/va/vro/GatewayConfiguration.java

@@ -0,0 +1,14 @@
+package gov.va.vro;
+
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class GatewayConfiguration {
+    @Bean
+    HomePageModel homePageModel(){
+        HomePageModel homePageModel = new HomePageModel();
+        return homePageModel;
+    }
+}

api-gateway/src/main/java/gov/va/vro/HomePageController.java

@@ -0,0 +1,18 @@
+package gov.va.vro;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+
+@Controller
+@RequiredArgsConstructor
+class HomePageController {
+    final HomePageModel homePageModel;
+
+    @GetMapping("/")
+    String index(final Model model) {
+        model.addAttribute("model", homePageModel);
+        return "index";
+    }
+}

api-gateway/src/main/java/gov/va/vro/HomePageModel.java

@@ -0,0 +1,10 @@
+package gov.va.vro;
+
+import lombok.Data;
+import org.springframework.beans.factory.annotation.Value;
+
+@Data
+class HomePageModel {
+    @Value("${vro.openapi.info.version}")
+    String version;
+}

api-gateway/src/main/java/gov/va/vro/OpenApiConfiguration.java

@@ -0,0 +1,47 @@
+package gov.va.vro;
+
+import gov.va.vro.propmodel.Info;
+import gov.va.vro.propmodel.OpenApiProperties;
+import io.swagger.v3.oas.annotations.OpenAPIDefinition;
+import io.swagger.v3.oas.models.OpenAPI;
+import io.swagger.v3.oas.models.info.Contact;
+import io.swagger.v3.oas.models.info.License;
+import io.swagger.v3.oas.models.servers.Server;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Slf4j
+@Configuration
+@RequiredArgsConstructor
+public class OpenApiConfiguration {
+  private final OpenApiProperties openApiProperties;
+
+  @Bean
+  public OpenAPI customOpenApi() {
+    Info info = openApiProperties.getInfo();
+    gov.va.vro.propmodel.Contact contact = info.getContact();
+    gov.va.vro.propmodel.License license = info.getLicense();
+
+    List<Server> servers =
+        openApiProperties.getServers().stream()
+            .map(server -> new Server().description(server.getDescription()).url(server.getUrl()))
+            .collect(Collectors.toList());
+
+    OpenAPI config =  new OpenAPI()
+            .info(
+                new io.swagger.v3.oas.models.info.Info()
+                    .title(info.getTitle())
+                    .description(info.getDescription())
+                    .version(info.getVersion())
+                    .license(new License().name(license.getName()).url(license.getUrl()))
+                    .contact(new Contact().name(contact.getName()).email(contact.getEmail())))
+            .servers(servers);
+    return config;
+  }
+}

app/src/main/java/gov/va/vro/config/propmodel/Contact.java → api-gateway/src/main/java/gov/va/vro/propmodel/Contact.java

@@ -1,4 +1,4 @@
-package gov.va.vro.config.propmodel;
+package gov.va.vro.propmodel;
 
 import lombok.Getter;
 import lombok.Setter;

app/src/main/java/gov/va/vro/config/propmodel/Info.java → api-gateway/src/main/java/gov/va/vro/propmodel/Info.java

@@ -1,14 +1,14 @@
-package gov.va.vro.config.propmodel;
+package gov.va.vro.propmodel;
 
 import lombok.Getter;
 import lombok.Setter;
 
 @Getter
 @Setter
 public class Info {
-  private String title = "VRO API";
-  private String description = "VRO Description";
-  private String version = "v1.0.25";
+  private String title = "API";
+  private String description = "Description";
+  private String version = "v0.0.0";
 
   private final Contact contact = new Contact();
 

app/src/main/java/gov/va/vro/config/propmodel/License.java → api-gateway/src/main/java/gov/va/vro/propmodel/License.java

@@ -1,4 +1,4 @@
-package gov.va.vro.config.propmodel;
+package gov.va.vro.propmodel;
 
 import lombok.Getter;
 import lombok.Setter;

api-gateway/src/main/java/gov/va/vro/propmodel/OpenApiProperties.java

@@ -0,0 +1,20 @@
+package gov.va.vro.propmodel;
+
+import gov.va.vro.propmodel.Info;
+import gov.va.vro.propmodel.Server;
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+@Getter
+@Setter
+@ConfigurationProperties(prefix = "vro.openapi")
+public class OpenApiProperties {
+  private final Info info = new Info();
+
+  private List<Server> servers = new ArrayList<Server>(Arrays.asList(new Server()));
+}

api-gateway/src/main/java/gov/va/vro/propmodel/Server.java

@@ -0,0 +1,11 @@
+package gov.va.vro.propmodel;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class Server {
+  private String description = "Local Server";
+  private String url = "/";
+}

api-gateway/src/main/resources/application.yml

@@ -0,0 +1,121 @@
+# This file contains shared properties across all environments; it is always loaded by Spring
+# See https://github.com/department-of-veterans-affairs/abd-vro/wiki/Configuration-settings#vros-use-of-spring-profiles
+
+management:
+  endpoints.web:
+    exposure.include: "*"
+  endpoint:
+    health:
+      show-details: always
+      probes:
+        enabled: true
+      group:
+        liveness.include: livenessState
+        readiness.include: readinessState, db
+  metrics:
+    enabled: true
+    distribution:
+      percentiles.http.server.requests: 0.5, 0.90, 0.95, 0.99, 0.999
+      percentiles-histogram.http.server.requests: true
+      sla.http.server.requests: 10ms, 50ms
+      slo.http.server.requests: 10ms, 50ms
+    tags:
+      group: starter
+      service: example
+      region: "${POD_REGION:local}"
+      stack: "${CLUSTER:dev}"
+      ns: "${NAMESPACE:example}"
+      pod: "${POD_ID:docker}"
+    web.server.request.autotime.enabled: true
+  server.port: 8061
+
+server:
+  ssl:
+    enabled: false
+  port: 8060
+  maxHttpHeaderSize: 48000
+  session:
+    timeout: 60
+  connection:
+    timeout: 60000
+  servlet:
+    session:
+      timeout: 120000
+
+spring:
+  application:
+    name: "vro-api"
+  servlet:
+    multipart:
+      maxFileSize: 25MB
+      maxRequestSize: 25MB
+      enabled: true
+    session:
+      timeout: 120000
+  resources:
+    add-mappings: false
+  http:
+    encoding:
+      force: true
+
+springdoc:
+  writer-with-default-pretty-printer: true
+  show-actuator: true
+  swagger-ui:
+    # http://localhost:8078/swaggerui will be forwarded to http://localhost:8078/webjars/swagger-ui/index.html
+    path: /swaggerui
+    operations-sorter: method
+    tagsSorter: alpha
+    # Populate API dropdown on the upper-right of Swagger UI
+    urls:
+      - name: 0. Gateway API
+        # API defined for this API Gateway
+        url: /v3/api-docs
+      - name: App API
+        # API defined for the VRO Java-base App
+        url: /app/v3/api-docs
+      - name: Contention Classification API
+        # Use the route defined under spring.cloud.gateway below
+        url: /contention-classification/openapi.json
+
+# TODO: Add Spring Cloud CircuitBreaker: https://spring.io/guides/gs/gateway/
+spring.cloud.gateway:
+  actuator.verbose.enabled: true
+  discovery:
+    locator:
+      enabled: false
+  routes:
+  # Each domain API should have one entry with a URI prefix
+  - id: vro-app
+    uri: http://localhost:8080
+    predicates:
+    - Path=/app/**
+    filters:
+    - RewritePath=/app/(?<path>.*), /$\{path}
+  - id: contention-classification-tenant
+    # TODO: add Swagger servers such that /contention-classification is used as the prefix for requests
+    uri: http://localhost:18000
+    predicates:
+    - Path=/contention-classification/**
+    filters:
+    - RewritePath=/contention-classification/(?<path>.*), /$\{path}
+
+log4j2:
+  formatMsgNoLookups: true
+
+vro:
+  openapi:
+    info:
+      title: "Automated Benefits Delivery (ABD): Virtual Regional Office (VRO) API"
+      description: "To improve benefit delivery to Veterans"
+      version: "3.0.0"
+      contact:
+        name: Premal Shah
+        email: "[email protected]"
+      license:
+        name: CCO 1.0
+        url: "https://github.com/department-of-veterans-affairs/abd-vro/blob/master/LICENSE.md"
+    servers:
+      -
+        description: "Server"
+        url: ${STARTER_OPENAPI_SERVERURL:/}

api-gateway/src/main/resources/templates/index.html

@@ -0,0 +1,24 @@
+<html>
+<body style="font-family: Arial">
+<h1>VRO API Gateway</h1>
+Automated Benefits Delivery - Virtual Regional Office (ABD-VRO)
+<p><a href="https://github.com/department-of-veterans-affairs/abd-vro">ABD-VRO GitHub Repo</a>
+</p>
+
+<h3>Swagger UI</h3>
+APIs for each VRO tenant is available via VRO's <a href="webjars/swagger-ui/index.html">Swagger UI</a>.
+<ul>
+    <li>Select the tenant from the "Select a definition" dropdown on the upper-right of the UI.</li>
+    <li>Each tenant page has a link to the API spec.</li>
+    <li>To use Swagger's "Try It" feature, make sure to select the correct server on the left dropdown.
+        For example, for the VRO App, select the "/app - via API Gateway" server.
+    </li>
+</ul>
+
+<h3>VRO info</h3>
+<ul>
+<li>VRO version: <span th:text="${model.version}" /></li>
+</ul>
+
+</body>
+</html>

app/build.gradle

@@ -19,12 +19,9 @@ dependencies {
   implementation project(':svc-bip-api')
 
   implementation 'org.springframework.boot:spring-boot-starter-web'
-  implementation 'org.springframework.boot:spring-boot-starter-validation'
   implementation 'org.springframework.boot:spring-boot-starter-security'
   implementation 'org.springframework.boot:spring-boot-starter-actuator'
   implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
-  implementation 'org.springframework.boot:spring-boot-starter-amqp'
-  implementation "com.vladmihalcea:hibernate-types-55:${hibernate_types_version}"
   implementation "org.springframework.security:spring-security-core:${spring_security_version}"
   implementation "org.springframework.security:spring-security-config:${spring_security_version}"
   implementation "org.springframework.security:spring-security-web:${spring_security_version}"
@@ -39,14 +36,7 @@ dependencies {
   implementation group: 'org.apache.httpcomponents', name: 'httpclient', version: '4.5.14'
   implementation 'io.jsonwebtoken:jjwt:0.2'
 
-  // Needed?
-  // implementation "org.postgresql:postgresql:${postgresql_version}"
-  runtimeOnly "org.postgresql:postgresql:${postgresql_version}"
-
   testRuntimeOnly "com.h2database:h2:${h2_version}"
-
-  testImplementation "org.apache.camel:camel-test-spring-junit5:${camel_version}"
-  testImplementation "io.jsonwebtoken:jjwt:0.2"
 }
 
 openApi {