I am using a spring boot application with #EnableZuulProxy annotation. But I would like to add custom routes during runtime. How is this possible?
Existing documentation only shows static examples, in which routes are defined in the application.yml. Could you point me to code snippets of my use case.
In the ZuulConfiguration I found a possibility to add routes routeLocator().getRoutes().add(route); but they are not applied to the runtime. What am I missing?
Thanks a lot. Cheers
Gerardo
What I did was subclass the SimpleRouteLocator class with my own RouteLocator class. Here is sample of what I did:
public class RouteLocator extends SimpleRouteLocator implements RefreshableRouteLocator {
#Autowired
private ZuulHandlerMapping zuulHandlerMapping;
private Map<String, ZuulRoute> routes = new ConcurrentHashMap<>();
public RouteLocator(TaskExecutor executor, String servletPath, ZuulProperties properties) {
super(servletPath, properties);
executor.execute(new ServiceWatcher());
}
#Override
public Map<String, ZuulRoute> locateRoutes() {
return this.routes;
}
#Override void refresh() {
this.doRefresh();
}
private class ServiceWatcher implements Runnable {
#Override
public void run(){
// Add your routes to this.routes here.
ZuulRoute route1 = new ZuulRoute("/somePath", "http://someResourceUrl:8080");
ZuulRoute route2 = new ZuulRoute("/someOtherPath", "some-service-id");
routes.put("/somePath", route1);
routes.put("/someOtherPath", route2);
zuulHandlerMapping.setDirty(true);
}
}
}
I'm not exactly sure when the ServiceWatcher gets called since in my actual code the ServiceWatcher wraps around a Kubernetes Watcher (since I am running Zuul in an OpenShift environment), but this should provide the gist of how to get started.
Related
I'm learning how to build an API Gateway using Spring Cloud. I've scoured through the documentation on how to pass a parameter and all examples seem to show them as hardcoded in. But what if I have a dynamic value?
For example I have this type of request: http://localhost:8080/people/lookup?searchKey=jdoe,
How do I pass in the "jdoe" part?
I tried the following code and it works only if I hardcode the value in the code.
i.e., .filters(f -> f.addRequestParameter("searchKey", "jdoe") .
That test also proves that my discovery server (Eureka) is working.
I'm not sure how to access the value using the provided builder methods. It's such a simple scenario but I'm surprised to find out there's not a lot of example or documentation for it so it must be just me.
#SpringBootApplication
#EnableEurekaClient
public class ApiGatewayApplication {
public static void main(String[] args) {
SpringApplication.run(ApiGatewayApplication.class, args);
}
#Bean
public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
return builder.routes()
.route("people-service", r -> r.path("/people/active-associates")
.uri("lb://people-service"))
.route(r -> r.path("/people/lookup")
.filters(f -> f.addRequestParameter("searchKey", howDoIPassDynamicValueHere))
.uri("lb://people-service")
.id("addrequestparameter_route"))
.build();
}
This obviously worked when I call the service directly because my microservice controller handles it like this using the #RequestParam...pretty straightforward:
#RestController
#RequestMapping(value = "/people")
public class PersonController {
#Autowired
private PersonService personService;
/**
* Searches by FirstName, Lastname or NetworkId.
*
* #param searchKey
* #return ResponseEntity<List<Person>>
*/
#GetMapping(value = "/lookup")
public ResponseEntity<List<Person>> findPersonsBySearchKey(#RequestParam(name = "searchKey") String searchKey) {
List<Person> people = personService.findActivePersonsByFirstLastNetworkId(searchKey.trim().toLowerCase());
return new ResponseEntity<List<Person>>(people, HttpStatus.OK);
}
}
Thanks to the comments, it started making sense to me. I guess I did overthink when I read the documentation about the filter's addRequestParameter() method. I thought that I would need to use that method if my requests have parameters. Been scratching my head for a day and I can't believe it's that simple. So I got it working by just removing that filter:
#SpringBootApplication
#EnableEurekaClient
public class ApiGatewayApplication {
public static void main(String[] args) {
SpringApplication.run(ApiGatewayApplication.class, args);
}
#Bean
public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
return builder.routes()
.route("people-service", r -> r.path("/people/active-associates")
.uri("lb://people-service"))
.route(r -> r.path("/people/lookup")
.uri("lb://people-service"))
.build();
}
}
I am currently using the spring cloud gateway project to build simple api gateway, the plan was to persist the route in mongodb, then refresh, so that the new route can be available. I have done something simple like this to get my route from mongo.
#Bean
public RouteLocator routeLocator(RouteLocatorBuilder builder){
List<CreateAPIRequest> apiRequestList = repository.findAll();
RouteLocatorBuilder.Builder routeLocator = builder.routes();
for (CreateAPIRequest request: apiRequestList) {
routeLocator
.route(r-> {
r.path("/"+request.getProxy().getListenPath())
.filters(f->f.stripPrefix(1))
.uri(request.getProxy().getTargetUrl())
});
}
return routeLocator.build();
}
I was able to create new route in the db, but I am unable to refresh on the fly.
I need to understand how to refresh the routes on the fly.
Thanks
Whenever you wish to update the routes dynamically send a RefreshRoutesEvent. The following component implements the event sending functionality.
#Component
public class GatewayRoutesRefresher implements ApplicationEventPublisherAware {
ApplicationEventPublisher publisher;
#Override
public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
publisher = applicationEventPublisher;
}
public void refreshRoutes() {
publisher.publishEvent(new RefreshRoutesEvent(this));
}
}
Here is a sample showing how to use the component above:
#Autowired
GatewayRoutesRefresher gatewayRoutesRefresher;
...
public void buildRoutes() {
// build your routes basing on your db entries then refresh the routes in gateway
...
gatewayRoutesRefresher.refreshRoutes();
}
You can find a more complete picture of the concept by looking into the following project code: https://github.com/botorabi/HomieCenter
SCG(Spring Cloud Gateway) has been provided RouteDefinitionRepository, you can write your own RouteDefinitionRepository, and implements RouteDefinitionRepository to override getRouteDefinitions method.
You can refer to this class: InMemoryRouteDefinitionRepository
For example:
#Service
public class MongodbDefinitionRepository implements RouteDefinitionRepository {
#Autowired
private RouteConfigDao routeConfigDao;
#Override
public Flux<RouteDefinition> getRouteDefinitions() {
// todo
List<RouteDefinition> routeConfigs = routeConfigDao.findAll();
return Flux.fromIterable(routeConfigs);
}
#Override
public Mono<Void> save(Mono<RouteDefinition> route) {
return route.flatMap(routeDefinition -> {
// todo
return Mono.empty();
});
}
#Override
public Mono<Void> delete(Mono<String> routeId) {
return routeId.flatMap(id -> {
// todo
int delete = routeConfigDao.delete(routeId);
if (delete > 0) {
return Mono.empty();
}
return Mono.defer(() -> Mono.error(new Exception("delete route definition error, routeId:" + routeId)));
});
}
}
How to refresh the routes on the fly
Enable actuator
place this in your application.yml
management:
endpoints:
web:
exposure:
include: gateway
POST http://ip:port/actuator/gateway/refresh
Publish RefreshRoutesEvent
#Service
public class MyPublishBiz implements ApplicationEventPublisherAware {
protected ApplicationEventPublisher publisher;
#Override
public void setApplicationEventPublisher(ApplicationEventPublisher publisher) {
this.publisher = publisher;
}
public Mono<Void> refresh() {
this.publisher.publishEvent(new RefreshRoutesEvent(this));
return Mono.empty();
}
}
I went quickly to the repo and the open issues.
And it seems that at the moment the only way to refresh the routes is from Actuator via:
/actuator/gateway/refresh
You can check the discussion here: https://github.com/spring-cloud/spring-cloud-gateway/issues/43
Can you use Consul for persisting your route definitions instead of mongo. Then a simple POST call to the actuator's refresh will reload your route definitions on the fly.
I am trying to create a simple spring boot app which takes list of routes and process it parallelly in routebuilder. I am using proceduretemplate to call my routes by defining my startroute: direct start. When i hit i am getting org.apache.camel.component.direct.DirectConsumerNotAvailableException: No consumers available on endpoint: Endpoint[direct://start].Exchange.[]. I am unable to figure out the issue here.below is my code.
TestController.java
#RestController
#RequestMapping(value = "/service")
#Component
public class TestController {
#EndpointInject(uri = "direct:start")
private ProducerTemplate template;
#RequestMapping(value = "/test",method =RequestMethod.GET)
public void getAccountDetails(){
ArrayList<String> callList = new ArrayList<String>();
callList.add("direct:phone");
callList.add("direct:sms");
callList.add("direct:email");
template.sendBody(callList);
}
CamelRoute.java
#Component
public class CamelRoute extends RouteBuilder {
final String BASE_ROUTE = "direct:start";
public void configure() throws Exception {
from(BASE_ROUTE).recipientList(body()).setParallelProcessing(true);
from("direct:phone").log("customer call made");
from("direct:sms").log("phone call made");
from("direct:email").log("email call made");
}
version
camel-spring-boot-starter', version: '2.17.0'
Thanks in advance.
I'm trying to disable a Zuul route to a microservice registered with Eureka at runtime (I'm using spring boot).
This is an example:
localhost/hello
localhost/world
Those two are the registered microservices. I would like to disable the route to one of them at runtime without shutting it down.
Is there a way to do this?
Thank you,
Nano
Alternatively to using Cloud Config, custom ZuulFilter can be used. Something like (partial implementation to show the concept):
public class BlackListFilter extends ZuulFilter {
#Override
public String filterType() {
return "pre";
}
...
#Override
public Object run() {
RequestContext ctx = RequestContext.getCurrentContext();
String uri = ctx.getRequest().getRequestURI();
String appId = uri.split("/")[1];
if (blackList.contains(appId)) {
ctx.setSendZuulResponse(false);
LOG.info("Request '{}' from {}:{} is blocked",
uri, ctx.getRequest().getRemoteHost(), ctx.getRequest().getRemotePort());
}
return null;
}
}
where blackList contains list of application IDs (Spring Boot application name) managed for example via some RESTful API.
After a lot of efforts I came up with this solution. First, I used Netflix Archaius to watch a property file. Then I proceeded as follows:
public class ApplicationRouteLocator extends SimpleRouteLocator implements RefreshableRouteLocator {
public ApplicationRouteLocator(String servletPath, ZuulProperties properties) {
super(servletPath, properties );
}
#Override
public void refresh() {
doRefresh();
}
}
Made the doRefresh() method public by extending SimpleRouteLocator and calling its method in the overridden one of the interface RefreshableRouteLocator.
Then I redefined the bean RouteLocator with my custom implementation:
#Configuration
#EnableConfigurationProperties( { ZuulProperties.class } )
public class ZuulConfig {
public static ApplicationRouteLocator simpleRouteLocator;
#Autowired
private ZuulProperties zuulProperties;
#Autowired
private ServerProperties server;
#Bean
#Primary
public RouteLocator routeLocator() {
logger.info( "zuulProperties are: {}", zuulProperties );
simpleRouteLocator = new ApplicationRouteLocator( this.server.getServletPrefix(),
this.zuulProperties );
ConfigurationManager.getConfigInstance().addConfigurationListener( configurationListener );
return simpleRouteLocator;
}
private ConfigurationListener configurationListener =
new ConfigurationListener() {
#Override
public void configurationChanged( ConfigurationEvent ce ) {
// zuulProperties.getRoutes() do something
// zuulProperties.getIgnoredPatterns() do something
simpleRouteLocator.refresh();
}
}
}
Every time a property in the file was modified an event was triggered and the ConfigurationEvent was able to deal with it (getPropertyName() and getPropertyValue() to extract data from the event). Since I also Autowired the ZuulProperties I was able to get access to it. With the right rule I could find whether the property of Zuul
zuul.ignoredPatterns
was modified changing its value in the ZuulProperties accordingly.
Here refresh context should work (as long as you are not adding a new routing rule or removing a currently existing one), if you are adding or removing routing rules, you have to add a new bean for ZuulProperties and mark it with #RefreshScope, #Primary.
You can autowire refreshEndpoint bean for example and apply refreshEndpoint.refresh() on the listener.
Marking a custom RouteLocator as primary will cause problems as zuul already has bean of same type marked as primary.
I'd like to add a new property source that could be used to read property values in an application. I'd like to do this using Spring. I have a piece of code like this in a #Configuration class:
#Bean
public static PropertySourcesPlaceholderConfigurer placeHolderConfigurer() {
PropertySourcesPlaceholderConfigurer properties = new PropertySourcesPlaceholderConfigurer();
MutablePropertySources sources = new MutablePropertySources();
MyCustomPropertySource propertySource = new MyCustomPropertySource("my custom property source");
sources.addFirst(propertySource);
properties.setPropertySources(sources);
return properties;
}
This seems to work pretty well. However, what it is also doing is overriding other property values (e.g. server.port property in application.properties file used by spring boot) which I don't want to overwrite. So the basic question is what's the best way to add this propertysource but not have it override other properties. Any way to grab the existing propertysources and simply add on to it?
I got this working by adding a custom initiailizer to my spring boot app:
#SpringBootApplication
public class MyApp {
public static void main(String[] args) {
new SpringApplicationBuilder(MyApp.class)
.initializers(new MyContextInitializer()) // <---- here
.run(args);
}
}
Where MyContextInitializer contains: -
public class MyContextInitializer implements
ApplicationContextInitializer<ConfigurableApplicationContext> {
public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
ConfigurableEnvironment environment = configurableApplicationContext.getEnvironment();
// Create map for properites and add first (important)
Map<String, Object> myProperties = new HashMap<>();
myProperties.put("some-prop", "custom-value");
environment.getPropertySources().addFirst(
new MapPropertySource("my-props", myProperties));
}
}
Note, if your application.yaml contains: -
some-prop: some-value
another-prop: this is ${some-prop} property
Then the initialize method will update the some-prop to custom-value and when the app loads it will have the following values at run-time:
some-prop: custom-value
another-prop: this is custom-value property
Note, if the initialize method did a simple System.setProperty call i.e.
public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
ConfigurableEnvironment environment = configurableApplicationContext.getEnvironment();
System.setProperty("some-prop", "custom-value");
}
... then the another-prop would be equal to this is some-value property which is not what we generally want (and we lose the power of Spring config property resolution).
Try setting IgnoreUnresolvablePlaceholders to TRUE. I had a similar problem which I was able to resolve in this way. In my case, I had another placeholderconfigurer, which was working - but properties in the second one were not being resolved unless I set this property to TRUE.
#Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer = new PropertySourcesPlaceholderConfigurer();
propertySourcesPlaceholderConfigurer.setIgnoreUnresolvablePlaceholders(Boolean.TRUE);
propertySourcesPlaceholderConfigurer.setIgnoreResourceNotFound(Boolean.TRUE);
return propertySourcesPlaceholderConfigurer;
}
Yet another possibility (after lots of experimentation, it's what worked for me) would be to declare your PropertySource inside a ApplicationContextInitializer and then inject that one in your SpringBootServletInitializer:
public class MyPropertyInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
private static final Logger logger = LoggerFactory.getLogger(ApplicationPropertyInitializer.class);
#Override
public void initialize(ConfigurableApplicationContext applicationContext) {
MyPropertySource ps = new MyPropertySource();
applicationContext.getEnvironment().getPropertySources().addFirst(ps);
}
}
public class MyInitializer extends SpringBootServletInitializer{
#Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
return super.configure(builder.initializers(new MyPropertyInitializer()));
}
}
You can perhaps add your propertySource straight into environment once it is initialized.
EDIT: As this is done AFTER the class is processed, you cannot expect the #Value annotations to pick up anything from this particular PropertySource in the same #Configuration class - or any other that is loaded before.
#Configuration
public class YourPropertyConfigClass{
#Value("${fromCustomSource}")
String prop; // failing - property source not yet existing
#Autowired
ConfigurableEnvironment env;
#PostConstruct
public void init() throws Exception {
env.getPropertySources().addFirst(
new MyCustomPropertySource("my custom property source"));
}
}
#Configuration
#DependsOn("YourPropertyConfigClass")
public class PropertyUser {
#Value("${fromCustomSource}")
String prop; // not failing
}
You could move the #PostConstruct to a separate #Configuration class and mark other classes using those properties #DependOn("YourPropertyConfigClass") (this works - but perhaps there is a better way to force configuration order?).
Anyway - it is only worth it, if MyCustomPropertySource cannot be simply added using #PropertySource("file.properties") annotation - which would solve the problem for simple property files.
If you implement PropertySourceFactory as such:
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.core.io.support.PropertySourceFactory;
public class CustomPropertySourceFactory implements PropertySourceFactory {
#Override
public PropertySource<?> createPropertySource(String name, EncodedResource resource) {
...
}
}
You can use the following property source:
#PropertySource(name="custom-prop-source", value="", factory=CustomPropertySourceFactory.class)
Kind of hack-ish, but it works.