I'm using feign with spring cloud
I have one micro service that needs to call 3 other micro services, each of these 3 micro services have one end point "/pay" but the implementation is completely different.
This works with feign if I create 3 feign interfaces and call the one I need.
My goal is to create one feign interface and call the service I need (the only thing that changes is the name, since the endpoint is the same for the 3) but I haven't found a way to inject the name in the interface.
This could be done using resttemplate since in runtime I know the service I need to call.
The idea behind this concept is to add more microservices without changing the first microservice.
Related
I have a monolithic Spring boot application that exposes a REST API /getUserList.
Now we are taking the micro service approach, so that we extracted some business code and create /getCountry microservice REST API.
Normally, /getUserList should call /getCountry to get all countries.
Now for testing purpose, I want to use these two REST API in the same server, but separately. What I can think of is to create two seperate JAR and let one call another. I want to know what is the right way to do this :
Should I list /getCountry as a module of /getUserList? Or should I create a separate project ?
You decided to break your monolith into microservices. You started on the right foot, separating the application logic based on the bounded contexts you defined. In this case you describe "countries" context and the "user" context.
Microservices are independently deployable, so you are correct, they have to be separate jars. Your "user" service will call the "countries" service via the network as usual in microservices architecture.
Usually, each microservice has their own repo (project), so that developers who have to work on the service, do not need to familiarize with a large codebase, or figure out why code not related to their service (bounded context) is there.
That being said, if currently your project is quite small you can decide to keep these as separate modules (do not import countries module in the user module) under the same project and break them later.
I am developing a bookstore application based on microservices architecture with Spring and Netflix OSS.
I made a shopping service, with all the stuff necessary to buy a book. But I need to integrate with two services.
One service is a shipping service, this is an internal service. Connected through a Feign client.
The other service is an inventory service, this is an external service. Connected through an external library. This is a problem because it's more difficult to mock.
In order to connect with this services from shopping service, I thought that the adapter pattern was a good idea. I made another service, a shopping adapter service, that is used to connect with the other two services. And with this architecture, I can test the shopping service mocking the adapter service.
But now I think that is a bit awkward solution.
Do you know which is the best architecture to connect with external or internal services?
First, is it correct that’s what I understand?
Compound Service --(use)--> shipping service
----------------------------(use)--> inventory service ( this project uses external
library )
If it is right, I think it is not difficult to mock.
Create an inventory microservice project for wrapping external library.
Because compound service doesn`t need to care what we need to use a certain library for inventory. Your Inventory microservice project just exposes endpoint for using inventory service.
In the microservices world, services are first class citizens. Microservices expose service endpoints as APIs and abstract all their realization details. The internal implementation logic, architecture, and technologies, including programming language, database, quality of services mechanisms, and more, are completely hidden behind the service API.
Then, You can mock Inventory service at your compound service test code.
#Configuration
class MessageHandlerTestConfiguration {
#Bean
public InventoryClient inventoryClient() {
return Mockito.mock(InventoryClient.class);
}
I don't think creating another microservice which you should maintain and monitor and keep resilient and high available etc. just to have a kind of facade or adapter is a good idea. This statement may be proved wrong for some very special cases but generally if you don't have a context to maintain then it is not a good idea to create a new microservice.
What I could recommend would be directly calling shipping service by paying attention to anti corruption layer pattern which keeps your actual domain's service code clean from other microservice's domain entities.
You can find some more information about anti corruption layer here https://softwareengineering.stackexchange.com/questions/184464/what-is-an-anti-corruption-layer-and-how-is-it-used
I am learning NativeScript + Angular2 with ServiceStack in C# as the backend.
For the app, I generated TypeScript classes using the typescript-ref command, for use with the JsonServiceClient in ServiceStack:
>typescript-ref http://192.168.0.147:8080 RestApi
It all looked sweet and dandy, until I discovered that it seems to ignore that the ServiceStack Services and Response DTOs are in different namespaces on the .NET side:
I have different branches of services, where the handlers for each service might differ slightly between the branches. This works well in ServiceStack, the Login and handlers work just as expected.
So, on the app/NativeScript/Angular2-side, I used the typescript-ref and generated the restapi.dtos.ts. The problem is it skips the namespace difference and just creates duplicate classes instead (from VSCode):
The backend WS in ServiceStack is built in this "branched" fashion so I don't have to start different services on different ports, but rather gather all of them on one port and keep it simple and clear.
Can my problem be remedied?
You should never rely on .NET namespaces in your public facing Services Contract. It's supported in .NET Clients but not in any other language which requires that each DTO be uniquely named.
In general your DTOs should be unique within your entire SOA boundary so that there's only 1 Test DTO which maps to a single schema definition which ensures that when it's sent through a Service Gateway, resolved through Service Discovery, published to a MQ Server, etc it only maps to a single DTO contract.
I have a very simple service project (SpringBootApplication) that exposes a REST endpoint via a Spring Boot controller class. The controller maps an /events endpoint that converts a simple incoming event DTO into a slightly different event entity object that is then persisted in a database via a org.springframework.data.repository.CrudRepository instance.
In my controller, I am only mapping the POST operator because I don't want my clients to be able to GET, PUT or DELETE data from the service.
During a security scan today, I discovered that the service is exposing a /eventsEntities endpoint, which appears to be mapping all of the CrudRepository verbs into the REST endpoint.
Any idea how I managed to enable this automatic endpoint and more importantly, how to disable it? I'm using Spring Boot 1.2.2.
After some additional digging, I realized that I had inadvertently included org.springframework.boot:spring-boot-starter-data-rest in my compile dependencies. That starter includes spring-data-rest-webmvc, which exposes JPA data over REST. Removing that dependency resolved the issue.
Hope my realization helps someone else in the future.
Given that one of the main benefits of Spring Data and the related REST repositories is that most of the time the developer doesn't have to worry about the underlying implementations, is there an out-of-the-box way to leverage the Spring Cloud Netflix libraries, specifically the Hystrix annotations in this case, without extending every call in the provided Repository interfaces or creating my own implementation?
Currently you need to wrap calls in another service whose methods are annotated with #HystrixCommand. Because of the way both Spring Data and the Hystrix Aspect work (they both create proxies), there would need to be specific integration in Spring Data for #HystrixCommand. #ccit-spence is right, you really want to put #HystrixCommand on the services calling into a Spring Data REST repository.