I would suggest you not to use @ConditionalOnExpression annotation for this.
Consider using @PreAuthorize instead. Yes, it's from spring-security.
With that you can protect each service from usage if it isn't enabled and dynamically toggle enabled/disabled state for it:
@SpringBootApplication
public class So44462763Application {
public static void main(String[] args) {
SpringApplication.run(So44462763Application.class, args);
}
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true) // <-- this is required for PreAuthorize annotation to work
public static class SecurityConfiguration extends WebSecurityConfigurerAdapter {
@Override
protected void configure(HttpSecurity http) throws Exception {
http.csrf().disable();
}
}
interface CxProperties {
boolean isServiceAEnabled();
boolean isServiceBEnabled();
boolean isServiceCEnabled();
boolean enableService(String service);
boolean disableService(String service);
}
@Component("cx")
public static class CxPropertiesImpl implements CxProperties {
private static final ConcurrentHashMap<String, Boolean> services = new ConcurrentHashMap<>(); //could be database/redis/property file/etc
@PostConstruct
private void init() {
//services.put("serviceA", true); //initial population from property file/network resource/whatever
}
public boolean isServiceAEnabled() {
return services.getOrDefault("serviceA", false);
}
public boolean isServiceBEnabled() {
return services.getOrDefault("serviceB", false);
}
public boolean isServiceCEnabled() {
return services.getOrDefault("serviceC", false);
}
//just a sample how you can dynamically control availability for each service
@Override
public boolean enableService(String service) {
services.put(service, true);
return services.getOrDefault(service, false);
}
@Override
public boolean disableService(String service) {
services.put(service, false);
return services.getOrDefault(service, false);
}
}
interface BusinessService {
String doSomething();
}
@Service("serviceA")
@PreAuthorize("@cx.serviceAEnabled")
public static class ServiceA implements BusinessService {
@Override
public String doSomething() {
return this.getClass().getSimpleName() + " doing some work";
}
}
@Service("serviceB")
@PreAuthorize("@cx.serviceBEnabled")
public static class ServiceB implements BusinessService {
@Override
public String doSomething() {
return this.getClass().getSimpleName() + " doing some work";
}
}
@Service("serviceC")
@PreAuthorize("@cx.serviceCEnabled")
public static class ServiceC implements BusinessService {
@Override
public String doSomething() {
return this.getClass().getSimpleName() + " doing some work";
}
}
@RestController
@RequestMapping("/api/work")
public static class WorkApi {
private static final Logger log = LoggerFactory.getLogger(WorkApi.class);
private final List<BusinessService> businessServices;
@Autowired
public WorkApi(final List<BusinessService> businessServices) {
this.businessServices = businessServices;
}
@GetMapping
public String doWork() {
final StringJoiner joiner = new StringJoiner(",");
for (BusinessService service : businessServices) {
try {
joiner.add(service.doSomething());
} catch (AccessDeniedException e) {
log.warn("Service {} is disabled.", service);
}
}
return joiner.toString();
}
}
@RestController
@RequestMapping("/api/control")
public static class ControlApi {
private final CxProperties cxProperties;
@Autowired
public ControlApi(final CxProperties cxProperties) {
this.cxProperties = cxProperties;
}
@PostMapping("{service}/enable")
public boolean enable(@PathVariable("service") String serviceName) {
return cxProperties.enableService(serviceName);
}
@PostMapping("{service}/disable")
public boolean disable(@PathVariable("service") String serviceName) {
return cxProperties.disableService(serviceName);
}
}
}
And here is a sample usage:
$ curl -u user:123 -XGET 'localhost:8080/api/work'
$ curl -u user:123 -XPOST 'localhost:8080/api/control/serviceC/enable'
true%
$ curl -u user:123 -XGET 'localhost:8080/api/work'
ServiceC doing some work%
$ curl -u user:123 -XPOST 'localhost:8080/api/control/serviceA/enable'
true%
$ curl -u user:123 -XGET 'localhost:8080/api/work'
ServiceA doing some work,ServiceC doing some work%
Using this approach you can control accessibility of services even without restart.
And all of this can be done without spring-security as well but involves a little bit more of manual work and might slightly decrease overall readability of your code.
