Add validation logic for server.proxies

- Implemented validation to ensure each server has at least one proxy defined.
- Added checks to verify that each referenced proxy exists in the global proxies configuration.
- Included error recording and wrapping for validation failures.

config/config.go

@@ -449,33 +449,21 @@ func (c *Config) ValidateGlobalConfig(ctx context.Context) *gerr.GatewayDError {
 		}
 	}
 
-	// if len(globalConfig.Clients) > 1 {
-	// 	seenConfigObjects = append(seenConfigObjects, "clients")
-	// }
-
-	// for configGroup := range globalConfig.Pools {
-	// 	if globalConfig.Pools[configGroup] == nil {
-	// 		err := fmt.Errorf("\"pools.%s\" is nil or empty", configGroup)
-	// 		span.RecordError(err)
-	// 		errors = append(errors, gerr.ErrValidationFailed.Wrap(err))
-	// 	}
-	// }
-
-	// if len(globalConfig.Pools) > 1 {
-	// 	seenConfigObjects = append(seenConfigObjects, "pools")
-	// }
-
-	// for configGroup := range globalConfig.Proxies {
-	// 	if globalConfig.Proxies[configGroup] == nil {
-	// 		err := fmt.Errorf("\"proxies.%s\" is nil or empty", configGroup)
-	// 		span.RecordError(err)
-	// 		errors = append(errors, gerr.ErrValidationFailed.Wrap(err))
-	// 	}
-	// }
-
-	// if len(globalConfig.Proxies) > 1 {
-	// 	seenConfigObjects = append(seenConfigObjects, "proxies")
-	// }
+	for configGroup := range globalConfig.Pools {
+		if globalConfig.Pools[configGroup] == nil {
+			err := fmt.Errorf("\"pools.%s\" is nil or empty", configGroup)
+			span.RecordError(err)
+			errors = append(errors, gerr.ErrValidationFailed.Wrap(err))
+		}
+	}
+
+	for configGroup := range globalConfig.Proxies {
+		if globalConfig.Proxies[configGroup] == nil {
+			err := fmt.Errorf("\"proxies.%s\" is nil or empty", configGroup)
+			span.RecordError(err)
+			errors = append(errors, gerr.ErrValidationFailed.Wrap(err))
+		}
+	}
 
 	for configGroup := range globalConfig.Servers {
 		if globalConfig.Servers[configGroup] == nil {
@@ -489,6 +477,24 @@ func (c *Config) ValidateGlobalConfig(ctx context.Context) *gerr.GatewayDError {
 		seenConfigObjects = append(seenConfigObjects, "servers")
 	}
 
+	// Each server configuration should have at least one proxy defined.
+	// Each proxy in the server configuration should be referenced in proxies configuration.
+	for serverName, server := range globalConfig.Servers {
+		if len(server.Proxies) == 0 {
+			err := fmt.Errorf("\"servers.%s\"  has no proxies defined", serverName)
+			span.RecordError(err)
+			errors = append(errors, gerr.ErrValidationFailed.Wrap(err))
+			continue
+		}
+		for _, proxyName := range server.Proxies {
+			if _, exists := c.globalDefaults.Proxies[proxyName]; !exists {
+				err := fmt.Errorf("\"servers.%s\" references a non-existent proxy \"%s\"", serverName, proxyName)
+				span.RecordError(err)
+				errors = append(errors, gerr.ErrValidationFailed.Wrap(err))
+			}
+		}
+	}
+
 	sort.Strings(seenConfigObjects)
 
 	if len(seenConfigObjects) > 0 && !reflect.DeepEqual(configObjects, seenConfigObjects) {