Spring Boot Starter Echo Proxy

A Spring Boot starter that provides a configurable proxy/mock server . It allows you to easily mock external services or proxy requests to real endpoints.

Features

• Mock HTTP endpoints with configurable responses
• Proxy requests to external services
• Dynamic configuration of endpoints via JSON or programmatic API
• Support for custom response headers
• Response modification capabilities
• Easy integration with Spring Boot applications
• Support for both Spring MVC and WebFlux stacks

Installation

Maven

Add the GitHub Packages repository and dependency to your pom.xml:

<repositories>
    <repository>
        <id>github</id>
        <name>GitHub areguig Apache Maven Packages</name>
        <url>https://maven.pkg.github.com/areguig/spring-boot-starter-echo-proxy</url>
    </repository>
</repositories>

<dependencies>
    <dependency>
        <groupId>io.github.areguig</groupId>
        <artifactId>spring-boot-starter-echo-proxy</artifactId>
        <version>0.1.0-SNAPSHOT</version>
    </dependency>
</dependencies>

Gradle

Add the GitHub Packages repository and dependency to your build.gradle:

repositories {
    maven {
        url = uri("https://maven.pkg.github.com/areguig/spring-boot-starter-echo-proxy")
    }
}

dependencies {
    implementation 'io.github.areguig:spring-boot-starter-echo-proxy:0.1.0-SNAPSHOT'
}

Or with Kotlin DSL (build.gradle.kts):

repositories {
    maven {
        url = uri("https://maven.pkg.github.com/areguig/spring-boot-starter-echo-proxy")
    }
}

dependencies {
    implementation("io.github.areguig:spring-boot-starter-echo-proxy:0.1.0-SNAPSHOT")
}

Configuration

Properties

Available configuration properties in application.properties or application.yml:

Property	Description	Default
echo.proxy.enabled	Enable/disable the proxy	true
echo.proxy.management-base-path	Base path for management endpoints	/echo-proxy
echo.proxy.config-file	Path to JSON configuration file	echo-proxy-config.json

Example:

echo:
  proxy:
    enabled: true
    management-base-path: /echo-proxy
    config-file: my-config.json

JSON Configuration

You can configure proxy endpoints using a JSON file. Create a file named echo-proxy-config.json (or as specified in echo.proxy.config-file):

[
  {
    "urlPattern": "/api/test",
    "mode": "MOCK",
    "method": "GET",
    "responseBody": "{\"message\":\"test\"}",
    "statusCode": 200,
    "responseHeaders": {
      "Content-Type": "application/json",
      "X-Custom-Header": "test-value"
    },
    "active": true
  },
  {
    "urlPattern": "/api/proxy",
    "mode": "PROXY",
    "method": "GET",
    "targetUrl": "http://external-service.com",
    "responseHeaders": {
      "X-Additional-Header": "custom-value"
    },
    "active": true
  }
]

Programmatic Configuration

You can also configure endpoints programmatically:

@Autowired
private ConfigurationStorage configStorage;

// Mock endpoint example
ProxyConfig mockConfig = new ProxyConfig();
mockConfig.setUrlPattern("/api/test");
mockConfig.setMode(ProxyMode.MOCK);
mockConfig.setMethod(HttpMethod.GET);
mockConfig.setResponseBody("{\"message\":\"test\"}");
mockConfig.setStatusCode(200);
mockConfig.setResponseHeaders(Map.of(
    "Content-Type", "application/json",
    "X-Custom-Header", "test-value"
));
mockConfig.setActive(true);
configStorage.addConfig(mockConfig);

// Proxy endpoint example
ProxyConfig proxyConfig = new ProxyConfig();
proxyConfig.setUrlPattern("/api/proxy");
proxyConfig.setMode(ProxyMode.PROXY);
proxyConfig.setMethod(HttpMethod.GET);
proxyConfig.setTargetUrl("http://external-service.com");
proxyConfig.setActive(true);
configStorage.addConfig(proxyConfig);

Management API

The library exposes REST endpoints to manage proxy configurations:

• GET /echo-proxy/configs - List all configurations
• POST /echo-proxy/configs - Create new configuration
• PUT /echo-proxy/configs/{id} - Update existing configuration
• DELETE /echo-proxy/configs/{id} - Delete configuration

Web Stack Support

The library automatically detects and works with both Spring MVC and Spring WebFlux stacks. No additional configuration is needed.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.