tessl/maven-com-alibaba-csp--sentinel-spring-cloud-gateway-adapter

Integration module providing flow control, traffic shaping, concurrency limiting, circuit breaking and system adaptive overload protection for Spring Cloud Gateway applications

—

Pending

Overview

Eval results

Files

Request Processing

Name: tessl/maven-com-alibaba-csp--sentinel-spring-cloud-gateway-adapter
Author: tessl

Components for parsing and extracting parameters from Spring WebFlux ServerWebExchange objects, enabling parameter-based flow control rules and request analysis.

Capabilities

ServerWebExchangeItemParser

Parses request items from Spring WebFlux ServerWebExchange, extracting various request attributes for use in Sentinel flow control rules.

/**
 * Parses request items from Spring WebFlux ServerWebExchange
 * Implements RequestItemParser<ServerWebExchange> interface
 */
public class ServerWebExchangeItemParser implements RequestItemParser<ServerWebExchange> {
    /**
     * Default constructor
     */
    public ServerWebExchangeItemParser();
    
    /**
     * Extracts the request path from the exchange
     * @param exchange - Server web exchange
     * @return String request path value
     */
    public String getPath(ServerWebExchange exchange);
    
    /**
     * Extracts the remote client IP address from the exchange
     * @param exchange - Server web exchange
     * @return String remote address or null if not available
     */
    public String getRemoteAddress(ServerWebExchange exchange);
    
    /**
     * Extracts a specific header value from the request
     * @param exchange - Server web exchange
     * @param key - Header name to extract
     * @return String header value or null if not present
     */
    public String getHeader(ServerWebExchange exchange, String key);
    
    /**
     * Extracts a URL query parameter value from the request
     * @param exchange - Server web exchange
     * @param paramName - Parameter name to extract
     * @return String parameter value or null if not present
     */
    public String getUrlParam(ServerWebExchange exchange, String paramName);
    
    /**
     * Extracts a cookie value from the request
     * @param exchange - Server web exchange
     * @param cookieName - Cookie name to extract
     * @return String cookie value or null if not present
     */
    public String getCookieValue(ServerWebExchange exchange, String cookieName);
}

Usage Examples:

import com.alibaba.csp.sentinel.adapter.gateway.sc.ServerWebExchangeItemParser;

// Create parser instance
ServerWebExchangeItemParser parser = new ServerWebExchangeItemParser();

// Extract request information (typically done within flow control rules)
String path = parser.getPath(exchange);
String clientIp = parser.getRemoteAddress(exchange);
String userAgent = parser.getHeader(exchange, "User-Agent");
String userId = parser.getUrlParam(exchange, "userId");
String sessionId = parser.getCookieValue(exchange, "JSESSIONID");

// Use in custom SentinelGatewayFilter
@Bean
public GlobalFilter customSentinelFilter() {
    ServerWebExchangeItemParser customParser = new ServerWebExchangeItemParser();
    return new SentinelGatewayFilter(customParser);
}

Integration with Flow Control Rules

Parameter-Based Rules

The extracted request parameters can be used in Sentinel flow control rules for fine-grained traffic control:

// Example: Configure parameter-based flow rule using extracted values
ParamFlowRule rule = new ParamFlowRule()
    .setResource("api-gateway")
    .setParamIdx(0) // First parameter (often path or client IP)
    .setCount(10)   // Limit to 10 requests
    .setDurationInSec(1);

ParamFlowRuleManager.loadRules(Collections.singletonList(rule));

Custom Parameter Extraction

You can extend ServerWebExchangeItemParser for custom parameter extraction logic:

public class CustomServerWebExchangeItemParser extends ServerWebExchangeItemParser {
    
    @Override
    public String getHeader(ServerWebExchange exchange, String key) {
        // Custom header processing logic
        String headerValue = super.getHeader(exchange, key);
        return processCustomHeader(headerValue);
    }
    
    // Add custom extraction methods
    public String getCustomAttribute(ServerWebExchange exchange, String attributeName) {
        return exchange.getAttribute(attributeName);
    }
    
    private String processCustomHeader(String headerValue) {
        // Custom processing logic
        return headerValue != null ? headerValue.toLowerCase() : null;
    }
}

Request Analysis Capabilities

Path Analysis

Extracts clean request path without query parameters
Useful for path-based routing and flow control rules
Returns normalized path value from Spring Cloud Gateway route processing

Client Identification

Extracts remote client IP address from request
Handles proxy scenarios through Spring WebFlux's remote address resolution
Returns null if remote address cannot be determined

Header Processing

Extracts any HTTP header by name
Case-insensitive header name matching
Returns first header value if multiple values exist

Query Parameter Extraction

Extracts URL query parameters by name
Handles URL-encoded parameter values
Returns first parameter value if multiple values exist

Cookie Management

Extracts cookie values by cookie name
Integrates with Spring WebFlux cookie handling
Provides null-safe cookie value extraction

Error Handling

Null Safety

All methods are designed to handle null input gracefully:

Return null when requested information is not available
Do not throw exceptions for missing headers, parameters, or cookies
Safe to use in flow control rule conditions

Exception Scenarios

Network Issues: getRemoteAddress() returns null if remote address cannot be determined
Missing Data: All extraction methods return null for missing data rather than throwing exceptions
Malformed Requests: Parser handles malformed requests gracefully without disrupting gateway processing

Install with Tessl CLI

npx tessl i tessl/maven-com-alibaba-csp--sentinel-spring-cloud-gateway-adapter

docs

request-processing.md

route-matching.md

tile.json

tessl/maven-com-alibaba-csp--sentinel-spring-cloud-gateway-adapter