Consul key value pair use for configuration in Spring-boot - spring-boot

I tried to change my registration server from "Eureka" to "Consul" and also Consul as my config server. Service discovery with Consul is a success.But I can't understand how to get key/value pair option to bootstrap my application. Is there any possible way I can do that?
I use spring boot with below dependancies
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
and this is my spring boot app ConsuleDemoApplication.class
#EnableDiscoveryClient
#SpringBootApplication
#RestController
public class ConsuleDemoApplication {
#RequestMapping("/")
public String home() {
return "Hello world";
}
public static void main(String[] args) {
SpringApplication.run(ConsuleDemoApplication.class, args);
}
}
and my bootstrap.yml is
spring:
cloud:
consul:
discovery:
healthCheckInterval: 15s
instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}
application:
name: consul_demo

spring boot configuration are ok. then go to consul ui using localhost:8500 and select key/value and add key value like below
then create it.then create configuration are like below
then restart your springboot application. your port change to 8084.
note: you can use YMAL or GIT2consul for more configuration

Related

Spring boot/Cloud Eureka DiscoveryClient - No such host is known

I want to try out microservices using 2.5.4 spring boot and getting problems in discovery
Steps:
Created a RestTemplate with #LoadBalanced, and trying to call the service using "application name in the url"
I have the register and fetch registry true in properties (thought this should get available services?)
Error: No such host is known
I am trying
#Autowired
private DiscoveryClient discoveryClient;
and do
discoveryClient.getInstances("myappservice-name").forEach((ServiceInstance s) -> {
System.out.println(ToStringBuilder.reflectionToString(s));
});
But all examples tell to use an endpoint? or commandLineRunner. Both I'm looking for auto loading
https://spring.io/guides/gs/service-registration-and-discovery/
https://spring.io/blog/2015/01/20/microservice-registration-and-discovery-with-spring-cloud-and-netflix-s-eureka
Not ok to call the below for each app
#RequestMapping("/service-instances/{applicationName}") public
List<ServiceInstance> serviceInstancesByApplicationName(
How can I register automatically?
EDIT: More detailed question
(1) SERVICE App
bootstrap - spring.application.name=pluralsight-toll-service
application props
server.port=0
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
eureka.instance.instance-id=${spring.application.name}:${random.int}
eureka.instance.hostname=localhost
management.endpoints.web.exposure.include=*
App
#SpringBootApplication
#EnableEurekaClient
public class PluralsightEurekaTollrateServiceApplication {
I see app registered in eureka server
(2) Client
bootstrap
spring.application.name=pluralsight-tollrate-billboard
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
application.props
server.port=8081
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
management.endpoints.web.exposure.include=*
App
#SpringBootApplication
#EnableEurekaClient
#EnableDiscoveryClient
public class PluralsightEurekaTollrateBillboardApplication {
Controller
#LoadBalanced
#Bean
public RestTemplate restTemplate(RestTemplateBuilder builder) {
return builder.build();
}
#Autowired
RestTemplate restTemplate;
#RequestMapping("/dashboard")
public String GetTollRate(#RequestParam int stationId, Model m) {
TollRate tr = restTemplate.getForObject("http://pluralsight-toll-service/tollrate/" + stationId, TollRate.class);
Error: pluralsight-toll-service host is unknown
How can call service from client using the name
Fixed the issue
Its all down to client project dependencies
<!-- <dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-netflix-eureka-client</artifactId>
<version>3.0.3</version>
</dependency> -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
The names are too close
spring-cloud-netflix-eureka-client is wrong
spring-cloud-starter-netflix-eureka-client is the right one
Because of the wrong one, I had to add eureka-client of com.netflix.eureka. Cleaned all and it works
(Also I was missing spring-cloud , as I was creating from eclipse. In future will use initializ only )

Load balancer does not contain an instance for the service

I want to use Eureka client with spring-cloud-starter-loadbalancer. But when I added configuration I get error. When I remove #LoadBalancerClient(name = "mail-service", configuration = LoadBalancerConfiguration.class) and LoadBalancerConfiguration class configuration it's working fine. I tried this code:
#FeignClient(name = "mail-service")
#LoadBalancerClient(name = "mail-service", configuration = LoadBalancerConfiguration.class)
public interface EmailClient {
#RequestMapping(method = RequestMethod.POST, value = "/engine/emails/register")
void setUserRegistration(CreateUserDTO createUserDTO);
}
#Configuration
public class LoadBalancerConfiguration {
#Bean
public ServiceInstanceListSupplier discoveryClientServiceInstanceListSupplier(ConfigurableApplicationContext context) {
return ServiceInstanceListSupplier.builder()
.withBlockingDiscoveryClient()
.withSameInstancePreference()
.withHealthChecks()
.build(context);
}
}
application.yml:
feign:
client:
config:
default:
connectTimeout: 5000
readTimeout: 5000
loggerLevel: basic
eureka:
client:
serviceUrl:
defaultZone: ${EUREKA_URI:http://localhost:8761/eureka}
fetchRegistry: true
healthcheck:
enabled: true
instance:
preferIpAddress: true
leaseRenewalIntervalInSeconds: 10
POM.xml dependencies
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>com.netflix.eureka</groupId>
<artifactId>eureka-core</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-loadbalancer</artifactId>
</dependency>
I get this error when I have only one target service.
[503] during [POST] to [http://mail-service/engine/emails/register] [EmailClient#setUserRegistration(CreateUserDTO)]: [Load balancer does not contain an instance for the service mail-service]
I use Release Train Version: 2020.0.3
Do you know what could be the problem?
Any application using load balancer should follow the below order
Start the Eureka Server
Start the instances of the Service one by one which have dependency
Any application relies on information from a service registry (i.e. Eureka). Until the application is registered with it's instances by the serviceId , the Eureka server will not be able to pick that instance while load-balancing.
In the code you have shared, the bean ServiceInstanceListSupplier is created in the configuration class along with the health checks ( .withHealthChecks() ). This is causing the application to fail as service has not been registered yet.
Also, the LoadBalancer config should not be in a #Configuration-annotated class instead, it should be a class passed for config via #LoadBalancerClient or #LoadBalancerClients annotation, as described here.
The only bean you need to instantiate is the ServiceInstanceListSupplier (if you add spring-cloud-starter-loadbalancer, LoadBalancerClientFactory etc. will be instantiated by the starter itself).
So your LoadBalancer configuration class should look like code below.
It should not be in the #Configuration class:
public class LoadBalancerConfiguration {
#Bean
public ServiceInstanceListSupplier instanceSupplier(ConfigurableApplicationContext context) {
return ServiceInstanceListSupplier.builder()
.withDiscoveryClient()
.withHealthChecks()
.build(context);
}
}
As explained in this link, the actual #Configuration class , will have the following annotation: #LoadBalancerClients(defaultConfiguration = LoadBalancerConfiguration .class).
Then, if you enable health-checks in the instances, it should work without any issues.

Why X-RateLimit-Remaining -1 in response header while using spring cloud api gateway ratelimit with redis?

I implemented ratelimit with redis in my spring cloud api gateway. Here is part of application.yml:
spring:
cloud:
gateway:
httpclient:
ssl:
useInsecureTrustManager: true
discovery:
locator:
enabled: true
routes:
- id: test-rest-service
uri: lb://test-rest-service
predicates:
- Path=/test/**
filters:
- RewritePath=/test/(?<path>.*), /$\{path}
- name: RequestRateLimiter
args:
key-resolver: "#{#userRemoteAddressResolver}"
redis-rate-limiter.replenishRate: 2
redis-rate-limiter.burstCapacity: 3
I called a GET API via postman and checked response header.
X-RateLimit-Remaining -1
X-RateLimit-Burst-Capacity 3
X-RateLimit-Replenish-Rate 2
The rate limit is not working. Why am I getting negative value for X-RateLimit-Remaining? What does it mean? How do I fix it?
This happened to me because there was no Redis instance launched. You have two options:
1) Download and run a Redis instance using docker:
docker run --name redis -d redis
2) You can use in testing an Embedded Redis Server as it is explained in the following article by adding the maven dependency:
<dependency>
<groupId>it.ozimov</groupId>
<artifactId>embedded-redis</artifactId>
<version>0.7.2</version>
<scope>test</scope>
</dependency>
And including the following snippet:
#TestConfiguration
public class TestRedisConfiguration {
private RedisServer redisServer;
public TestRedisConfiguration() {
this.redisServer = new RedisServer(6379);
}
#PostConstruct
public void postConstruct() {
redisServer.start();
}
#PreDestroy
public void preDestroy() {
redisServer.stop();
}
}
I faced the same issue recently. In my case, there was an older version of Redis installed which caused X-RateLimit-Remaining to be set to -1 constantly.
redis-cli shutdown

Spring boot 2 yaml property work but highlights in IDE

I have yaml config in my Spring boot app with my properties:
#app configs
my.messages.max_count: 5
my.messages.delay: 100
my.schedulers.charge_delay: 5000
It work but IntellijIDE highlights this lines and say:
Cannot resolve configuration property 'my.schedulers.charge_delay' less... (Ctrl+F1)
Checks Spring Boot application .yaml configuration files. Highlights unresolved and deprecated configuration keys and invalid values. Works only for Spring Boot 1.2 or higher
try this:
my:
messages:
max_count: 5
delay: 100
charge_delay: 5000
....
....
you are not using the yml syntax.
EDIT:
You can write your own Config class like this:
Config class:
#Configuration
#EnableConfigurationProperties
#ConfigurationProperties(prefix = "my")
public class YamlConfig {
private String delay;
public String getDelay() {
return url;
}
public void setDelay(String delay) {
this.delay = delay;
}
}
pom:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
yml:
my:
delay: 5
best regards

Spring Cloud Feign/Ribbon with corporate proxy

I want to consume a REST service from the outside world behind a corporate proxy with authentication.
How do I configure Spring Boot + Spring Cloud Feign/Ribbon to use our proxy?
I believe you're looking for something like this:
import feign.Feign;
import okhttp3.OkHttpClient;
import java.net.InetSocketAddress;
import java.net.Proxy;
...
Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("proxy-url", 1234));
OkHttpClient okHttpClient = new OkHttpClient.Builder().proxy(proxy).build();
Feign.builder()
.client(new feign.okhttp.OkHttpClient(okHttpClient))
.target(...);
You just have to additionally add compile 'io.github.openfeign:feign-okhttp:9.5.0' to your project.
The target clause contains your defined Interface. Further reference: https://github.com/OpenFeign/feign
Turns out there is actually a much easier solution.
The following information will be helpful (also for more advanced use cases):
Spring Cloud Commons HTTP Factories
Overriding Feign Defaults
OpenFeign Client can run with several HTTP Clients.
By default it uses java.net.URLConnection, but you can also use ApacheHttpClient or OkHttpClient.
Using Apache Http Client
Here is what you can do to set a proxy using ApacheHttpClient:
Add the following two dependencies to your pom.xml:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<!-- Dependency to switch HttpClient implementation from java.net.URLConnection to Apache HTTP Client -->
<!-- See also: FeignAutoConfiguration for details. -->
<!-- See also: https://cloud.spring.io/spring-cloud-commons/reference/html/#http-clients -->
<!-- See also: https://cloud.spring.io/spring-cloud-openfeign/reference/html/#spring-cloud-feign-overriding-defaults -->
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-httpclient</artifactId>
</dependency>
In your app expose the following bean:
// see: https://cloud.spring.io/spring-cloud-commons/reference/html/#http-clients
#Bean
public HttpClientBuilder proxiedHttpClient() {
String proxyHost = "client-envoy";
Integer proxyPort = 80
String proxyScheme = "http";
return HttpClientBuilder.create()
.setProxy(new HttpHost(proxyHost, proxyPort, proxyScheme));
}
That's it - nothing else needs to be configured in application.yaml since ApacheHttpClient will be used by default, if it is on the classpath.
Using Ok Http Client
To set a proxy using OkHttpClient you do a similar thing:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-okhttp</artifactId>
</dependency>
In your application.yml make sure to enable OkHttpClient and disable ApacheHttpClient:
spring:
cloud:
httpclientfactories:
ok:
enabled: true
apache:
enabled: false
feign:
okhttp:
enabled: true
httpclient:
enabled: false
Instead of HttpClientBuilder expose a bean of type OkHttpClient.Builder.
Spring cloud feign supports three underlying implementations:
Default
Apache HttpClient
OkHttpClient
If using Default:
Create this spring bean (say by defining inside class with #Configuration annotation), no changes required in application properties/yml:
#Bean
public Client feignClient() {
return new Client.Proxied(
null, null, new Proxy(Proxy.Type.HTTP, new InetSocketAddress(proxyHost, proxyPort)));
}
If using Apache HttpClient:
that means you have feign.httpclient.enabled: true in application.yml and below in your pom.xml or build.gradle:
pom.xml
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-httpclient</artifactId>
</dependency>
build.gradle
implementation 'io.github.openfeign:feign-httpclient'
Create this spring bean (say by defining inside class with #Configuration annotation):
#Bean
public CloseableHttpClient feignClient() {
return HttpClientBuilder.create().setProxy(new HttpHost(proxyHost, proxyPort)).build();
}
If using OkHttpClient:
that means you have feign.okhttp.enabled: true in application.yml and below in your pom.xml or build.gradle:
pom.xml
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-okhttp</artifactId>
</dependency>
build.gradle
implementation 'io.github.openfeign:feign-okhttp'
Create this spring bean (say by defining inside class with #Configuration annotation):
#Bean
public OkHttpClient feignClient() {
return new OkHttpClient.Builder()
.proxy(new Proxy(Proxy.Type.HTTP, new InetSocketAddress(proxyHost, proxyPort)))
.build();
}

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