feign client http proxy configuration

gistfile1.txt

🔹 application-local.yml


proxy:
  enabled: true
  host: proxy.local.corp
  port: 8080
  auth:
    enabled: true
    username: ${PROXY_USER}
    password: ${PROXY_PASS}
    
    
🔹 application-prod.yml (server)

proxy:
  enabled: true
  host: proxy.prod.corp
  port: 8080
  auth:
    enabled: false
    
 
 
 @Data
@ConfigurationProperties(prefix = "proxy")
public class ProxyProperties {

    private boolean enabled;
    private String host;
    private int port;

    private Auth auth = new Auth();

    @Data
    public static class Auth {
        private boolean enabled;
        private String username;
        private String password;
    }
}


4️⃣ Conditional Apache HttpClient Creation
@Configuration
@RequiredArgsConstructor
public class FeignProxyHttpClientConfig {

    private final ProxyProperties proxyProperties;

    @Bean
    @ConditionalOnProperty(name = "proxy.enabled", havingValue = "true")
    public Client feignClientWithProxy() {

        HttpClientBuilder builder = HttpClients.custom();

        // Configure proxy
        HttpHost proxy = new HttpHost(
                proxyProperties.getHost(),
                proxyProperties.getPort()
        );
        builder.setProxy(proxy);

        // Conditional authentication
        if (proxyProperties.getAuth().isEnabled()) {
            CredentialsProvider credentialsProvider =
                    new BasicCredentialsProvider();

            credentialsProvider.setCredentials(
                    new AuthScope(proxyProperties.getHost(),
                                  proxyProperties.getPort()),
                    new UsernamePasswordCredentials(
                            proxyProperties.getAuth().getUsername(),
                            proxyProperties.getAuth().getPassword()
                    )
            );
            builder.setDefaultCredentialsProvider(credentialsProvider);
        }

        return new ApacheHttpClient(builder.build());
    }
}


@FeignClient(
    name = "hotel-external-client",
    url = "${hotel.service.url}",
    configuration = FeignProxyHttpClientConfig.class
)
public interface HotelExternalClient {

    @GetMapping("/hotels/{id}")
    HotelResponse getHotel(@PathVariable String id);
}