Unknown property ‘AddRequestHeader’ for type in Spring Cloud Gateway Service

The error message you’re encountering, Unknown property 'AddRequestHeader' for type 'org.springframework.cloud.gateway.filter.FilterDefinition', indicates that the property AddRequestHeader is not being recognized as a valid filter in the Spring Cloud Gateway configuration. This could be due to a few reasons, such as incorrect syntax or a missing filter configuration.

Here’s how you can properly use the AddRequestHeader filter in Spring Cloud Gateway.

1. Correct Use of AddRequestHeader in application.yml

The correct way to configure AddRequestHeader in the Spring Cloud Gateway application.yml file is as follows:

spring:
  cloud:
    gateway:
      routes:
        - id: product_route
          uri: http://localhost:8081
          predicates:
            - Path=/products/**
          filters:
            - AddRequestHeader=X-Request-Source, My-Gateway  # Proper syntax for AddRequestHeader filter

In this example:

• AddRequestHeader: This is the filter you’re using to add a custom header to the request.
• X-Request-Source: The name of the header.
• My-Gateway: The value of the header.

This filter adds the header X-Request-Source with the value My-Gateway to all requests that pass through this route.

2. Ensure the Correct Dependency is Included

Make sure that the Spring Cloud Gateway dependency is included in your pom.xml or build.gradle file. For Maven, your pom.xml should include:

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>

If you’re using Gradle, add this to your build.gradle:

implementation 'org.springframework.cloud:spring-cloud-starter-gateway'

Ensure that you are using a compatible version of Spring Cloud Gateway that supports this filter. For example, AddRequestHeader has been supported since Spring Cloud Gateway 2.x.

3. Check Spring Cloud Version Compatibility

Ensure that your Spring Cloud version is compatible with the configuration you’re using. For instance, if you’re using the Spring Cloud Hoxton or Greenwich release, AddRequestHeader should work. Check your project’s spring-cloud-dependencies version in your pom.xml:

spring:
  cloud:
    gateway:
      routes:
        - id: product_route
          uri: http://localhost:8081
          predicates:
            - Path=/products/**
          filters:
            - AddRequestHeader=X-Request-Source, My-Gateway
    

4. Proper YAML Syntax

Ensure the YAML file has the correct indentation and syntax. YAML is sensitive to indentation, so the filter configurations must be indented properly.

5. Verify IDE Cache

Sometimes IDEs like VSCode or IntelliJ may have stale caches that trigger false warnings. Try:

• Invalidating the cache and restarting your IDE.
• Running mvn clean install or gradle clean build to ensure your dependencies and configuration are correct.

Full Example of application.yml:

spring:
  cloud:
    gateway:
      routes:
        - id: product_route
          uri: http://localhost:8081
          predicates:
            - Path=/products/**
          filters:
            - AddRequestHeader=X-Request-Source, My-Gateway

This should resolve the issue, and AddRequestHeader will work correctly for your gateway routing configuration.

If the problem persists after these steps, ensure that your dependencies and Spring Cloud versions are up-to-date and compatible.