I have a spring webapp that communicates with external service over kafka. IS it possible to somehow test contract between those services?
Yes you can. Spring Cloud Contract supports CDC with messaging. If you're using Spring Cloud Stream - the work to be done is trivial. If not then you'll have to implement your own as presented in this issue - Spring Cloud Contract and plain Spring AMQP . Summing it up it's enough for both consumer and producer to implement a custom org.springframework.cloud.contract.verifier.messaging.MessageVerifier bean that will be responsible for receiving and sending of messages via Kafka
Related
Following documentation, there are multiple ways to integrate Google Cloud PubSub events with Spring application:
Spring Cloud GCP has several modules for sending messages to Pub/Sub
topics and receiving messages from Pub/Sub subscriptions using the
Spring Framework. You can use these modules independently or combine
them for different use cases:
Spring Cloud GCP Pub/Sub Starter lets you send and receive messages
using helper classes and call the Pub/Sub Java client library for more
advanced scenarios.
Spring Integration Channel Adapters for Pub/Sub
let you connect Spring Integration Message Channels with Pub/Sub.
Spring Cloud Stream Binder for Pub/Sub lets you use Pub/Sub as
messaging middleware in Spring Cloud Stream applications.
I don't have full understanding - what are those different use cases mentioned, and how to determine, which module is best for which use case?
Application (Dockerized Spring Boot app, deployed to Kubernetes in GCP) I am working on is rather simple, it is expected to act upon received PubSub event, it is not going to publish any events itself.
Spring Cloud GCP Pub/Sub Starter module contains the java client classes for pub sub which will be used by your spring application to perform administrative and functional operations (ie. sending and receiving messages).
Spring Integration Channel Adapters for Pub/Sub module is utilized when your spring application uses Message Channels. This module will help routing message between message channel and pub/sub using channel adapters.
Spring Cloud Stream Binder for Pub/Sub module is used in Spring Cloud Stream Applications in order to utilize cloud Pub/Sub API.
Since, your application requirements are basic you can easily go for Spring Cloud GCP Pub/Sub Starter module. For more information you can refer to this Google documentation.
I'm trying to build an application with a couple of services. One service publishes details to a rabbitMQ queue, another spring boot application has to consume them and send the correct details to the correct user. The front end is developed in reactJS. How can I implement the spring boot consuming and sending to the subscribed user part? Any reference is appreciated. Can I use the web socket in spring boot to this?
I have worked with spring cloud data flow and rabbitmq and kafka but i would like to know if it would be possible to install scdf with google pub/sub.
I don't want to create a stream (new app spring cloud stream) with source or sink to gcp i want google pub/sub over spring cloud data flow server to use as an intermediate messaging broker.
Any suggestions?
Yes, you can use Spring dataflow and GCP Pub Sub link.
Through the use of one of many Spring Cloud Stream Binders, many
different messaging middleware products can be used. The following
popular platforms are among the list supported by Spring Cloud Data
Flow:
1.Kafka Streams
2.Amazon Kinesis
3.Google Pub/Sub
4.Solace PubSub+
5.Azure Event
Hubs You can find more information like the the current list of Spring
Cloud Stream Binders here library as a dependency to the application.
Spring Cloud Stream supports Google PubSub (partner maintained) binder implementation link.
Here you can find a related SO question Spring dataflow and GCP Pub Sub.
I'm trying to use the baggage propagation offered by Spring Cloud Sleuth. In the calls that use the Feign client I don't have any kind of problem, I can propagate custom fields, while while using JmsTemplate of Spring JMS I can't propagate the same fields.
My application is a Spring Boot application, version 2.1.5, with Spring Cloud version Greenwich.SR1.
In order to put the custom fields, I use
ExtraFieldPropagation.set("communicationId", "123456");
while, inside my application.properties, I put
spring.sleuth.baggage-keys= communicationId
I expect that the same functionality present for the Feign client, is also present for the producer JMS. Where am I wrong?
I am new to Microservice and JMS likes to know how can I
create a subscription
read the subscription
Using Spring Boot and JMS
To get started with Spring Boot and JMS use this getting started guide https://spring.io/guides/gs/messaging-jms/
Once you have that sorted then adding the microservices is just a matter of adding the Spring MVC and Rest components which you could first experiment as a standalone project and then integrate with the JMS application.
To get started with Spring Book and Microservices use the getting started guide https://spring.io/guides/gs/rest-service/
JMS not part of Java SE. You need Java EE or Spring.
I'm not sure queues are the best way to solve the problem.
I'd recommend Spring Boot.
Subscription maintenance isn't something that the queue would do.
A simple REST service would manage this nicely. You'll need a persistence layer to save subscription information.