Add client persistence

pom.xml

@@ -30,6 +30,26 @@
 		<java.version>17</java.version>
 	</properties>
 	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-jpa</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.xerial</groupId>
+			<artifactId>sqlite-jdbc</artifactId>
+			<scope>runtime</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.hibernate.orm</groupId>
+			<artifactId>hibernate-community-dialects</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.flywaydb</groupId>
+			<artifactId>flyway-core</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-security</artifactId>

src/main/java/com/litoralregas/backend_gateway/BackendGatewayApplication.java

@@ -1,13 +1,15 @@
 package com.litoralregas.backend_gateway;
 
+import com.litoralregas.backend_gateway.gateway.ProxyProperties;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 
 @SpringBootApplication
+@EnableConfigurationProperties(ProxyProperties.class)
 public class BackendGatewayApplication {
 
 	public static void main(String[] args) {
 		SpringApplication.run(BackendGatewayApplication.class, args);
 	}
-
 }

src/main/java/com/litoralregas/backend_gateway/client/ClientEntity.java

@@ -1,4 +1,56 @@
 package com.litoralregas.backend_gateway.client;
 
+import jakarta.persistence.*;
+
+@Entity
+@Table(name = "clients")
 public class ClientEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(nullable = false, unique = true)
+    private String name;
+
+    @Column(name = "backend_base_url", nullable = false)
+    private String backendBaseUrl;
+
+    @Column(nullable = false)
+    private boolean enabled = true;
+
+    @Column(name = "created_at", nullable = false, insertable = false, updatable = false)
+    private String createdAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getBackendBaseUrl() {
+        return backendBaseUrl;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public String getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public void setBackendBaseUrl(String backendBaseUrl) {
+        this.backendBaseUrl = backendBaseUrl;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
 }

src/main/java/com/litoralregas/backend_gateway/client/ClientRepository.java

@@ -1,4 +1,10 @@
 package com.litoralregas.backend_gateway.client;
 
-public class ClientRepository {
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.Optional;
+
+public interface ClientRepository extends JpaRepository<ClientEntity, Long> {
+
+    Optional<ClientEntity> findByName(String name);
 }

src/main/java/com/litoralregas/backend_gateway/config/WebClientConfig.java

@@ -1,14 +1,25 @@
 package com.litoralregas.backend_gateway.config;
 
+import com.litoralregas.backend_gateway.gateway.ProxyProperties;
+import io.netty.channel.ChannelOption;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.client.reactive.ReactorClientHttpConnector;
 import org.springframework.web.reactive.function.client.WebClient;
+import reactor.netty.http.client.HttpClient;
 
 @Configuration
 public class WebClientConfig {
 
     @Bean
-    public WebClient webClient(WebClient.Builder builder) {
-        return builder.build();
+    public WebClient webClient(WebClient.Builder builder, ProxyProperties proxyProperties) {
+        HttpClient httpClient = HttpClient.create()
+                .option(ChannelOption.CONNECT_TIMEOUT_MILLIS,
+                        Math.toIntExact(proxyProperties.getConnectTimeout().toMillis()))
+                .responseTimeout(proxyProperties.getResponseTimeout());
+
+        return builder
+                .clientConnector(new ReactorClientHttpConnector(httpClient))
+                .build();
     }
 }

src/main/java/com/litoralregas/backend_gateway/gateway/BackendProxyService.java

@@ -1,48 +1,79 @@
 package com.litoralregas.backend_gateway.gateway;
 
 import jakarta.servlet.http.HttpServletRequest;
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Service;
 import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.reactive.function.client.WebClientResponseException;
 
 @Service
 public class BackendProxyService {
 
     private final WebClient webClient;
-    private final String devBackendUrl;
+    private final ProxyProperties proxyProperties;
 
-    public BackendProxyService(
-            WebClient webClient,
-            @Value("${gateway.dev-backend-url}") String devBackendUrl
-    ) {
+    public BackendProxyService(WebClient webClient, ProxyProperties proxyProperties) {
         this.webClient = webClient;
-        this.devBackendUrl = devBackendUrl;
+        this.proxyProperties = proxyProperties;
     }
 
     public String getHealth() {
         return webClient.get()
-                .uri(devBackendUrl + "/actuator/health")
+                .uri(proxyProperties.getBackendBaseUrl() + "/actuator/health")
                 .retrieve()
                 .bodyToMono(String.class)
                 .block();
     }
 
     public ResponseEntity<String> proxy(HttpServletRequest request, String body) {
+
         String path = request.getRequestURI().replaceFirst("/api/backend", "");
         String query = request.getQueryString();
 
-        String targetUrl = devBackendUrl + path + (query != null ? "?" + query : "");
+        String targetUrl =
+                proxyProperties.getBackendBaseUrl()
+                        + path
+                        + (query != null ? "?" + query : "");
 
-        String response = webClient
+        try {
+            WebClient.RequestBodySpec requestSpec = webClient
                     .method(HttpMethod.valueOf(request.getMethod()))
-                .uri(targetUrl)
+                    .uri(targetUrl);
+
+            String contentType = request.getContentType();
+
+            if (contentType != null) {
+                requestSpec.header("Content-Type", contentType);
+            }
+
+            String accept = request.getHeader("Accept");
+
+            if (accept != null) {
+                requestSpec.header("Accept", accept);
+            }
+
+            ResponseEntity<String> response = requestSpec
                     .bodyValue(body != null ? body : "")
                     .retrieve()
-                .bodyToMono(String.class)
+                    .toEntity(String.class)
                     .block();
 
-        return ResponseEntity.ok(response);
+            return ResponseEntity
+                    .status(response.getStatusCode())
+                    .headers(response.getHeaders())
+                    .body(response.getBody());
+
+        } catch (WebClientResponseException ex) {
+            return ResponseEntity
+                    .status(ex.getStatusCode())
+                    .body(ex.getResponseBodyAsString());
+
+        } catch (Exception ex) {
+            return ResponseEntity
+                    .status(HttpStatus.BAD_GATEWAY)
+                    .body("Backend unavailable");
+        }
     }
 }

src/main/java/com/litoralregas/backend_gateway/gateway/ProxyProperties.java

@@ -0,0 +1,37 @@
+package com.litoralregas.backend_gateway.gateway;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+import java.time.Duration;
+
+@ConfigurationProperties(prefix = "gateway.proxy")
+public class ProxyProperties {
+
+    private String backendBaseUrl;
+    private Duration connectTimeout = Duration.ofSeconds(3);
+    private Duration responseTimeout = Duration.ofSeconds(10);
+
+    public String getBackendBaseUrl() {
+        return backendBaseUrl;
+    }
+
+    public void setBackendBaseUrl(String backendBaseUrl) {
+        this.backendBaseUrl = backendBaseUrl;
+    }
+
+    public Duration getConnectTimeout() {
+        return connectTimeout;
+    }
+
+    public void setConnectTimeout(Duration connectTimeout) {
+        this.connectTimeout = connectTimeout;
+    }
+
+    public Duration getResponseTimeout() {
+        return responseTimeout;
+    }
+
+    public void setResponseTimeout(Duration responseTimeout) {
+        this.responseTimeout = responseTimeout;
+    }
+}

src/main/resources/application.yaml

@@ -5,5 +5,22 @@ spring:
   application:
     name: backend-gateway
 
+  datasource:
+    url: jdbc:sqlite:./data/backend-gateway.db
+    driver-class-name: org.sqlite.JDBC
+
+  jpa:
+    database-platform: org.hibernate.community.dialect.SQLiteDialect
+    hibernate:
+      ddl-auto: none
+    show-sql: true
+
+  flyway:
+    enabled: true
+    locations: classpath:db/migration
+
 gateway:
-  dev-backend-url: http://10.100.1.2:18450
+  proxy:
+    backend-base-url: http://10.100.1.2:18450
+    connect-timeout: 3s
+    response-timeout: 10s

src/main/resources/db/migration/V1__create_clients.sql

@@ -0,0 +1,7 @@
+CREATE TABLE clients (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name TEXT NOT NULL UNIQUE,
+    backend_base_url TEXT NOT NULL,
+    enabled INTEGER NOT NULL DEFAULT 1,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);