Spring Boot 3.0 이상, Spring Security에서 CORS 설정

@Configuration
@EnableWebSecurity
public class SecurityConfig {
    
	//  CORS 설정
    CorsConfigurationSource corsConfigurationSource() {
        return request -> {
            CorsConfiguration config = new CorsConfiguration();
            config.setAllowedHeaders(Collections.singletonList("*"));
            config.setAllowedMethods(Collections.singletonList("*"));
            config.setAllowedOriginPatterns(Collections.singletonList("http://localhost:3000")); // ⭐️ 허용할 origin
            config.setAllowCredentials(true);
            return config;
        };
    }

    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        http
                .cors(corsConfigurer -> corsConfigurer.configurationSource(corsConfigurationSource()))
                .csrf(AbstractHttpConfigurer::disable)
                .authorizeHttpRequests(authorize ->
                        authorize
                                .requestMatchers("/login").permitAll()
                );

        return http.build();
    }
}