I've got the following project structure:
project
- serviceA
- serviceB
- serviceC
- serviceD
And I would like to have a common kafka connector in all the project services. Something like this:
public class CommonProcessor {
private final CommonService commonService;
public CommonProcessor(final CommonService commonService) {
this.commonService= commonService;
}
#Incoming("channel-name")
public CompletionStage<Void> process(final Message<CommonMessage> message) {
final CommonMessage commonMessage = message.getPayload();
commonService.commonMethod(commonMessage.getAttribute());
return message.ack();
}
}
With its corresponding configuration:
mp.messaging.incoming.channel-name.connector=smallrye-kafka
mp.messaging.incoming.channel-name.topic=channel-name
mp.messaging.incoming.channel-name.value.deserializer=foo.bar.CommonDeserializer
How could I share this CommonProcessor (and its configuration) between all services?
Can I put it in a common jar and add it as a dependency in all services? I've tried this option but it does not work because of the configuration. When starting the service with the dependency it says Impossible to bind mediators, some media
tors are not connected: [foo.bar.CommonProcessor#process]
Can it be done through an extension? In this case, I have the same question, how can I share the configuration in application.properties?
Related
I have a simple boot application where I have added open api swagger dependency
springdoc-openapi-ui
along with these properties
springdoc.swagger-ui.disable-swagger-default-url=true
springdoc.swagger-ui.configUrl=/v3/api-docs/swagger-config
springdoc.swagger-ui.path=/swagger-ui.html
I am getting these error (when calling http://localhost:8080/swagger-ui/index.html):
No API definition provided.
this is my controller :
#RestController
public class HelloWorld {
#GetMapping("sayHi")
public String sayHi(){
return "Hi Beno";
}
}
Any idea ?
When using a different endpoint to serve the OpenAPI Config, you'll need to set two properties
// This will set UI to fetch the config's URL from "somePath"
springdoc.swagger-ui.configUrl=somePath
// You also need to serve the config file from the endpoint at "somePath"
springdoc.api-docs.path=somePath
Thanks for Spring Boot Admin!
I am using it with Spring Cloud Kubernetes, our k8s pods only get discovered when we start the Spring Boot Admin, after the service pods have been started.
It seems looking at InstanceDiscoveryListener, the discovery of clients,
will happen based on events. Like ApplicationReadyEvent (When starting) and i.e. InstanceRegisteredEvent.
Is it correct to say, that Spring Boot Admin, will not try to discover periodically? If so how do I make sure an event is fired from the application to Spring boot admin picks it up and registers the instance?
Especially to make sure, that instanced are registered when they are started after spring boot admin, was started. (The order in which k8s pods are started is arbitrary/hard to control, something in general we don't want to do).
Thank You!
Christophew
Version:
springBootAdminVersion = '2.0.1'
springCloudVersion = 'Finchley.RELEASE'
springCloudK8s = '0.3.0.RELEASE'
Not sure if this is the best way to solve it but seems to work:
class TimedInstanceDiscoveryListener extends InstanceDiscoveryListener {
private static final Logger log = LoggerFactory.getLogger(TimedInstanceDiscoveryListener.class);
public TimedInstanceDiscoveryListener(DiscoveryClient discoveryClient, InstanceRegistry registry, InstanceRepository repository) {
super(discoveryClient, registry, repository);
log.info("Starting custom TimedInstanceDiscoveryListener");
}
#Scheduled(fixedRate = 5000)
public void periodicDiscovery() {
log.info("Discovering new pod / services");
super.discover();
}
}
#Bean
#ConfigurationProperties(prefix = "spring.boot.admin.discovery")
public InstanceDiscoveryListener instanceDiscoveryListener(ServiceInstanceConverter serviceInstanceConverter,
DiscoveryClient discoveryClient,
InstanceRegistry registry,
InstanceRepository repository) {
InstanceDiscoveryListener listener = new TimedInstanceDiscoveryListener(discoveryClient, registry, repository);
listener.setConverter(serviceInstanceConverter);
return listener;
}
I am currently integrating Spring Cloud Vault Config into a Spring Boot application. From the home page:
Spring Cloud Vault Config reads config properties from Vaults using the application name and active profiles:
/secret/{application}/{profile}
/secret/{application}
/secret/{default-context}/{profile}
/secret/{default-context}
I would like to instead provide my own location from which to pull properties from Vault which does not start with /secret (e.g. /deployments/prod). I've been looking through the reference documentation but I haven't found anyway to specify this -- is it possible?
I was able to use the Generic Backend properties to massage the paths into what I was looking for. Something like:
spring.cloud.vault:
generic:
enabled: true
backend: deployments
profile-separator: '/'
default-context: prod
application-name: my-app
This will also unfortunately pickup Vault locations like deployments/my-app and deployments/prod/activeProfile so be careful not to have any properties in these locations that you don't want to be picked up.
It looks like there is a desire (and an implementation) to allow for these paths to be specified more programmatically.
It should be done this way.
Have a Configuration class
#Configuration
public class VaultConfiguration {
#Bean
public VaultConfigurer configurer() {
return new VaultConfigurer() {
#Override
public void addSecretBackends(SecretBackendConfigurer configurer) {
configurer.add("secret/my-app/path-1");
configurer.add("secret/my-app/path-2");
configurer.registerDefaultGenericSecretBackends(false);
}
};
}
}
This way you can scan your secrets placed in custom path
Regards
Arun
I solved the same problem in my Kotlin project. But it works in Java too.
Problem
I wanted to specify vault paths in yaml config, so i ended up with the following solution, that allows you to specify paths directly in bootstrap.yml using clear syntax, as:
spring:
cloud:
vault:
paths: "secret/your-app"
Solution:
Create VaultConfig class in your project, with the following content:
package com.your.app.configuration
import org.springframework.beans.factory.annotation.Value
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty
import org.springframework.cloud.vault.config.VaultConfigurer
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
#Configuration
#ConditionalOnProperty(
prefix = "spring.cloud.vault", value = ["paths"],
matchIfMissing = false
)
class VaultConfig {
#Value("\${spring.cloud.vault.paths}")
private lateinit var paths: List<String>
#Bean
fun configurer(): VaultConfigurer {
return VaultConfigurer { configurer ->
paths.forEach {
configurer.add(it)
}
configurer.registerDefaultGenericSecretBackends(false)
configurer.registerDefaultDiscoveredSecretBackends(false)
}
}
}
Create spring.factories file in src/main/resources/META-INF/spring.factories with a content:
org.springframework.cloud.bootstrap.BootstrapConfiguration=com.your.app.configuration.VaultConfig
Don't forget to specify valid reference to your config instead of
com.your.app.configuration.VaultConfig
spring.factories allows your VaultConfig
happen in the bootstrap context, as documentation says.
Now you can specify desired paths in your bootstrap.yml, as follows:
spring:
cloud:
vault:
paths:
- "secret/application"
- "secret/your-app"
And it should work.
I have service which runs some init scripts after application startup (implemented with ApplicationListener<ApplicationReadyEvent>). In this scripts I need to call another services with RestTemplate which is #LoadBalanced. When the call to service is invoked there's no information about instances of remote service because discovery server was not contacted at that time (I guess).
java.lang.IllegalStateException: No instances available for api-service
at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.execute(RibbonLoadBalancerClient.java:79)
So is there way how to get list of available services from discovery server at application startup, before my init script will execute?
Thanks
edit:
The problem is more related to fact, that in current environment (dev) all services are tied together in one service (api-service). So from within api-service I'm trying to call #LoadBalanced client api-service which doesn't know about self? Can I register some listener or something similar to know when api-service (self) will be available?
here are the sample applications. I'm mainly interested how to have working this method
edit2:
Now there could be the solution to create EurekaListener
public static class InitializerListener implements EurekaEventListener {
private EurekaClient eurekaClient;
private RestOperations restTemplate;
public InitializerListener(EurekaClient eurekaClient, RestOperations restTemplate) {
this.eurekaClient = eurekaClient;
this.restTemplate = restTemplate;
}
#Override
public void onEvent(EurekaEvent event) {
if (event instanceof StatusChangeEvent) {
if (((StatusChangeEvent) event).getStatus().equals(InstanceInfo.InstanceStatus.UP)) {
ResponseEntity<String> helloResponse = restTemplate.getForEntity("http://api-service/hello-controller/{name}", String.class, "my friend");
logger.debug("Response from controller is {}", helloResponse.getBody());
eurekaClient.unregisterEventListener(this);
}
}
}
}
and then register it like this:
EurekaEventListener initializerListener = new InitializerListener(discoveryClient, restTemplate);
discoveryClient.registerEventListener(initializerListener);
However this is only executed only when application is registered to discovery service first time. Next time when I stop the api-service and run it again, event is not published. Is there any other event which can I catch?
Currently, in Camden and earlier, applications are required to be registered in Eureka before they can query for other applications. Your call is likely too early in the registration lifecycle. There is an InstanceRegisteredEvent that may help. There are plans to work on this in the Dalston release train.
I am trying Ribbon configuration with RestTemplate based on bookmark service example but without luck, here is my code:
#SpringBootApplication
#RestController
#RibbonClient(name = "foo", configuration = SampleRibbonConfiguration.class)
public class BookmarkServiceApplication {
public static void main(String[] args) {
SpringApplication.run(BookmarkServiceApplication.class, args);
}
#Autowired
RestTemplate restTemplate;
#RequestMapping("/hello")
public String hello() {
String greeting = this.restTemplate.getForObject("http://foo/hello", String.class);
return String.format("%s, %s!", greeting);
}
}
with error page as below:
Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.
Tue Mar 22 19:59:33 GMT+08:00 2016
There was an unexpected error (type=Internal Server Error, status=500).
No instances available for foo
but if I remove annotation #RibbonClient, everything will be just ok,
#RibbonClient(name = "foo", configuration = SampleRibbonConfiguration.class)
and here is SampleRibbonConfiguration implementation:
public class SampleRibbonConfiguration {
#Autowired
IClientConfig ribbonClientConfig;
#Bean
public IPing ribbonPing(IClientConfig config) {
return new PingUrl();
}
#Bean
public IRule ribbonRule(IClientConfig config) {
return new AvailabilityFilteringRule();
}
}
Is it because RibbonClient can not work with RestTemplate together?
and another question is that does Ribbon configuration like load balancing rule could be configured via application.yml configuration file?
as from Ribbon wiki, seems we can configure Ribbon parameters like NFLoadBalancerClassName, NFLoadBalancerRuleClassName etc in property file, does Spring Cloud also supports this?
I'm going to assume you're using Eureka for Service Discovery.
Your particular error:
No instances available for foo
can happen for a couple of reasons
1.) All services are down
All of the instances of your foo service could legitimately be DOWN.
Solution: Try visiting your Eureka Dashboard and ensure all the services are actually UP.
If you're running locally, the Eureka Dashboard is at http://localhost:8761/
2.) Waiting for heartbeats
When you very first register a service via Eureka, there's a period of time where the service is UP but not available. From the documentation
A service is not available for discovery by clients until the
instance, the server and the client all have the same metadata in
their local cache (so it could take 3 heartbeats)
Solution: Wait a good 30 seconds after starting your foo service before you try calling it via your client.
In your particular case I'm going to guess #2 is likely what's happening to you. You're probably starting the service and trying to call it immediately from the client.
When it doesn't work, you stop the client, make some changes and restart. By that time though, all of the heartbeats have completed and your service is now available.
For your second question. Look at the "Customizing the Ribbon Client using properties" section in the reference documentation. (link)