Spring Cloud Integration test, embedded kafka vs testcontainers - apache-kafka

I have a Spring cloud stream application which I need to make an integration test for (to be specific using cucumber). The application communicate with other services using Kafka message broker. From what I know I could make this work using either a kafka testcontainers or using spring provided embedded kafka. But what I don't know is which one would be the best solution so are there anything that the testcontainer could do but embedded can't or the other way around? (use cases or example would be appreciate!)
p.s This integration should be able to run on ci/cd pipeline.

It is called embedded for a reason. It really can be only accessed from the process which spawned it. With Testcontainers you really can reuse existing container and have access to it from the other process. But that's probably to exotic.
I guess with properly configured Testcontainers you can reach as much as possible similarities with the prod you'd deploy your solution. The embedded Kafka might be limited in some areas, e.g. SSL configuration or so.

Related

Are there any ways to write integration tests for Reactive Kafka in Spring?

I need to write integration tests and mock reactive Kafka consumer. I see there're ways to do it with blocking Kafka, like using #EmbeddedKafka but was not able to find information about reactive
As linked in the comments, reactor-kafka project themselves use TestContainers for integration tests. If you don't run tests in an environment with Docker, then spring-kafka-test's EmbeddedKafka, or junit-kafka project should still work with Reactive-based Kafka clients since you really only need bootstrap.servers property to point at any valid broker server.
Regarding mocks, you don't need an actual broker; that's the point of mocking. Their source code does include mock classes, too.

Is there an integration between Spring Batch and Spring Cloud Stream?

My project has a lot of Spring Batch Jobs.
I have requirement to create externalized configuration for message brokers (example Kafka, rabbitMQ etc.).
I want to use spring cloud stream since it has various binders to solve this problem.
Hence i wanted to understand if there is an integration between the two frameworks, please explain.

Spring boot Kogito Mongodb integration

I'm working on creating a kogito bpm spring boot project. I'm very happy to see reduced level of complexity on integration on jbpm in spring boot with the help of KOGITO. I'm struggling to find answers for my question, so posting them here,
Kogito is a open source cloud offering for jbpm. I'm I correct?
I see only mongodb or infinispan can only be used or supported with Kogito. I can't integrate psql with kogito. I'm I correct?
I successfully created the spring boot kogito mongodb project and when I placed a .bpmn file in the resource folder, automatically endpoints got created. I was able to access, run the process and get response. But I don't see any entries created in MONGODB :| I don't even see the table being created. The .bpmn contains a simple hello world flow with start+scripttask+end nodes. Please explain help me understand this. Is the RuntimeMangar configured for per request stratergy? How can I change it?
Answers inline.
Kogito is a open source cloud offering for jbpm. I'm I correct?
Kogito is open-source and has jBPM integrated into its codebase to run on a cloud-native environment. In addition, a lot has been made to make it also run with native compilation if used with Quarkus.
I see only mongodb or infinispan can only be used or supported with Kogito. I can't integrate psql with kogito. I'm I correct?
To this date, Kogito has the following add-ons to support persistence:
Infinispan
Postgres
MongoDB
JDBC (so you can extend to support any database you wish)
See more about it here https://docs.jboss.org/kogito/release/latest/html_single/#con-persistence_kogito-developing-process-services.
But I don't see any entries created in MONGODB
Do you mind sharing a reproducer? Have you taken a look at the examples in https://github.com/kiegroup/kogito-examples/tree/stable/process-mongodb-persistence-springboot? This example shows a call to a sub-process that relies on a user task. Hence the process must be persisted to fire up again on a new request to solve the task. However, since your process starts and ends in one request, there's nothing to be persisted in the DB:
Runtime persistence is intended primarily for storing data that is required to resume workflow execution for a particular process instance. Persistence applies to both public and private processes that are not yet complete. Once a process completes, persistence is no longer applied. This persistence behavior means that only the information that is required to resume execution is persisted.

Zookeeper/Kafka with Tomcat - Possible At All?

I was wondering if someone has used zookeeper/kafka embeeded within Tomcat. I know that Kafka requires Zookeeper, but does it mean that I have to run Kafka and Zookeeper as separate instances? So far I cannot see any use cases where everything has been bolt in. Could anyone advise?
My question is more around the concept of using zookeeper and kafka as a jar within the same tomcat web application.
Both Kafka and Zookeeper are meant to be used in a stand-alone fashion, run as separate processes.
They should even be on different machines/vms/containers than the tomcat web application.
You also probably want a Zookeeper cluster of 3-5 machines, rather than a single one, at least for production.
Both of them have Java clients though, for you to interact from the web application with them, and those are OK to include.

Micro services with JBOSS

I am new to Jboss, want to know if micro services architecture is a right choice on JBOSS. I cannot change the application server as it is decided by client architect and I have no choice.
Want to know whether we can develop micro services with underlying JBOSS application server.
I understand Spring boot comes with embedded tomcat container, which makes it flexible to stop and start, deploy individual service with no impact to other services.
However will that architecture works with JBoss too.
Please suggest.
Thanks,
I actually developed a feasibility study to investigate the solution you mentioned. My conclusion is that it is totally viable to use Micro Service principles in a JBoss Platform.
I used the combination of JBoss \ Spring Boot \ Netflix to create successful Micro Service stack, I personally do that to find a solution to the transaction problem (multiple micro services collaborating) and the fan out problem which caused because excessive Network communication and Serialization costs.
I also wrote a blog about the subject, you might find more details there if you like to, here is the link.
Micro Services – Fan Out, Transaction Problems and Solutions with Spring Boot/JBoss and Netflix Eureka
By the definition what micro services are, then conceptually yes. A micro service is a service that is an independent unit, it could deployed, updated, and undeployed independently without affecting any unrelated part of your application. So that would mean having multiple instances of JBoss for MS and your application calling them through some sort of gateway or any other mechanism depending on your use case. If you plan to deploy all your MS in the same JBoss instance then it defeats the very purpose of a MS. Given that, JBoss wouldn't be a right choice for MS deployment because it will only make your MS deployment infrastructure quite heavy.
Depending on what your client's requirements are, your could possibly keep your webapp in JBoss and deploy your MS containers separately.
It depends on what you want to get out of microservices.
Some of the developers at my organisation looked at Spring Boot but concluded that it's best off being run as a standalone container rather than in JBoss, otherwise you've effectively got two container frameworks competing (SB and JBoss) and a range of associated issues.
Deploying microservices in JBoss won't give you the same flexibility as a true container system like Docker. With Docker you create standalone packages for your microservices that contain all the code, system tools, runtime environment, etc. It can be as small or large as it needs to be. JBoss on the other hand is a large container running a single JVM designed to hold multiple applications. The level of isolation is not the same, and it's not efficient to have JBoss as a container for a single microservice so you have to appropriately size and then deploy to the instance to make use of the resources it has available.
If you're looking at microservices as a way to gain greater control over service lifecycle management (deployment, versioning, deprecating, etc.) as opposed to an automated, web-scale component deployment model a la Netflix or LinkedIn, you could do this adequately with JBoss.
I'm actually looking to do something along these lines here. It won't be true microservices but by packaging and deploying individual, properly versioned APIs rather than monolithic applications and following most of the other principles of microservice development (componentisation, business function focus, stateless etc.) we will be hopefully better able to manage and benefit from our APIs.
Our APIs will all be behind an API gateway and load balancer so we can choose how we distribute the microserves distributed across the JBoss instances and balance resource usage as required. Note that our organisation is relatively small and has relatively low and predictable traffic so this approach should work fine. Your needs however may be different.