feat: Spring cloud gateway routing (#3031)

Signed-off-by: Pavel Jareš <pavel.jares@broadcom.com>
Signed-off-by: Elena Kubantseva <elena.kubantseva@broadcom.com>
Co-authored-by: Elena Kubantseva <elena.kubantseva@broadcom.com>

.github/workflows/containers.yml

@@ -192,8 +192,6 @@ jobs:
                 image: ghcr.io/balhar-jakub/gateway-service:${{ github.run_id }}-${{ github.run_number }}
             cloud-gateway-service:
                 image: ghcr.io/balhar-jakub/cloud-gateway-service:${{ github.run_id }}-${{ github.run_number }}
-                env:
-                    APIML_SERVICE_GATEWAY_PROXY_ENABLED: false
             discoverable-client:
                 image: ghcr.io/balhar-jakub/discoverable-client:${{ github.run_id }}-${{ github.run_number }}
             mock-services:

cloud-gateway-service/src/main/java/org/zowe/apiml/cloudgatewayservice/config/RoutingConfig.java

@@ -11,16 +11,9 @@
 package org.zowe.apiml.cloudgatewayservice.config;
 
 import org.springframework.beans.factory.annotation.Value;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
-import org.springframework.cloud.client.discovery.ReactiveDiscoveryClient;
-import org.springframework.cloud.gateway.discovery.DiscoveryLocatorProperties;
 import org.springframework.cloud.gateway.filter.FilterDefinition;
-import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.zowe.apiml.cloudgatewayservice.service.ProxyRouteLocator;
-import org.zowe.apiml.cloudgatewayservice.service.RouteLocator;
-import org.zowe.apiml.util.CorsUtils;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -33,20 +26,6 @@ public class RoutingConfig {
     @Value("${apiml.service.ignoredHeadersWhenCorsEnabled:-}")
     private String ignoredHeadersWhenCorsEnabled;
 
-    @Bean
-    @ConditionalOnProperty(name = "apiml.service.gateway.proxy.enabled", havingValue = "false")
-    public RouteLocator apimlDiscoveryRouteDefLocator(
-        ReactiveDiscoveryClient discoveryClient, DiscoveryLocatorProperties properties, List<FilterDefinition> filters, ApplicationContext context, CorsUtils corsUtils) {
-        return new RouteLocator(discoveryClient, properties, filters, context, corsUtils);
-    }
-
-    @Bean
-    @ConditionalOnProperty(name = "apiml.service.gateway.proxy.enabled", havingValue = "true")
-    public RouteLocator proxyRouteDefLocator(
-        ReactiveDiscoveryClient discoveryClient, DiscoveryLocatorProperties properties, List<FilterDefinition> filters, ApplicationContext context, CorsUtils corsUtils) {
-        return new ProxyRouteLocator(discoveryClient, properties, filters, context, corsUtils);
-    }
-
     @Bean
     public List<FilterDefinition> filters() {
         FilterDefinition circuitBreakerFilter = new FilterDefinition();

cloud-gateway-service/src/main/java/org/zowe/apiml/cloudgatewayservice/filters/HeaderRouteStepFilterFactory.java

@@ -0,0 +1,62 @@
+/*
+ * This program and the accompanying materials are made available under the terms of the
+ * Eclipse Public License v2.0 which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-v20.html
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Copyright Contributors to the Zowe Project.
+ */
+
+package org.zowe.apiml.cloudgatewayservice.filters;
+
+import lombok.Data;
+import org.springframework.cloud.gateway.filter.GatewayFilter;
+import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
+import org.springframework.stereotype.Service;
+
+/**
+ * This filter is responsible to update request header during the routing. The header contain a locator to which server
+ * route. It could contain also multiple steps separated by /.
+ *
+ * In the case header contain multiple steps the filter remove just the first part, otherwise it remove header at all.
+ *
+ * Examples:
+ *      "step1/step2/step3" > "step2/step3"
+ *      "node"              > null (removed)
+ */
+@Service
+public class HeaderRouteStepFilterFactory extends AbstractGatewayFilterFactory<HeaderRouteStepFilterFactory.Config>  {
+
+    public HeaderRouteStepFilterFactory() {
+        super(Config.class);
+    }
+
+    @Override
+    public GatewayFilter apply(Config config) {
+        String header = config.getHeader();
+        return (exchange, chain) -> {
+            if (exchange.getRequest().getHeaders().containsKey(header)) {
+                exchange.mutate().request(request -> exchange.getRequest().mutate().headers(headers -> {
+                    String headerValue = headers.getFirst(header);
+                    int index = headerValue.indexOf("/");
+                    if ((index >= 0) && (index + 1 < headerValue.length())) {
+                        headers.set(header, headerValue.substring(index + 1));
+                    } else {
+                        headers.remove(header);
+                    }
+                }));
+            }
+
+            return chain.filter(exchange);
+        };
+    }
+
+    @Data
+    public static class Config {
+
+        private String header;
+
+    }
+
+}