learningbyexample/kotlin-event-driven-petstore

An example of a Kotlin Event Drive Pet Store

go-microservice

An educational project for creating an event-driven pet store in Kotlin

Domain diagram

Pets Domain components

TBC

TBC

kotlin-event-driven-petstore's Issues

Initial reading

This is a place holder issue with videos and examples to read

CQRS by Martin Fowler
https://martinfowler.com/bliki/CQRS.html

Event Sourcing by Martin Fowler
https://martinfowler.com/eaaDev/EventSourcing.html

Introduction to Domain Driven Design, CQRS and Event Sourcing by Kenneth Truyers
https://www.kenneth-truyers.net/2013/12/05/introduction-to-domain-driven-design-cqrs-and-event-sourcing/

The Future of Event-driven Microservices with Spring Cloud Stream by Kenny Bastani
https://www.youtube.com/watch?v=M9i8ORKqXQI

Event Sourcing and CQRS with Spring Stream by Jakub Pilimon
https://www.youtube.com/watch?v=eqPMmotEfsA

Spring PetClinic Sample Application Build Status by Pivotal
https://github.com/spring-projects/spring-petclinic

[FEATURE] add error mapping to insertIfNotExist

Describe the feature
We should add error mapping to insertIfNotExist

[FEATURE] Add the components for the domain

Describe the feature
We need to create the components defined in the domain,

Additional context

[FEATURE] Find pet by id

Describe the feature
Create an endpoint to be able to find a pet by id.

[FEATURE] Install Kafka operator in kubernets

Describe the feature
We have to install and configure a kafka in Kubernetes

Useful link: https://strimzi.io/quickstarts/

[FEATURE] Create a service to initialise the database

Describe the feature
Create a service to initialise the database, it should be able to be called to perform that action.

[FEATURE] Test infra code

Describe the feature
We should have tests for the code that creates the infra.

[FEATURE] Create a library for DTO validation

Describe the feature
Create a new library for DTO validation using reactor.

[FEATURE] Remove stored procedures

Describe the feature
Currently, we use stored procedures to insert categories, breeds, vaccines and tags, we should remove then and do normal SQLs

[FEATURE] Make pet-stream to be a rest service that executes a task on a startup

Describe the feature
The pet-stream service should have a rest service in order to be able to add health checks in a future.
The service should also be able to run a task on the startup.

[FEATURE] Move sql files to separate folder

Describe the feature
We should move the sql files used to initializate the database to a separate folder and run them only on test.

[FEATURE] Get pet details from database

Describe the feature
We should get the pet details from a postgresql.

[FEATURE] Adding Ktlint

Describe the feature
In order to have a consistent code formatting we should include Ktlint

Additional context
We could use the maven plugin : https://github.com/gantsign/ktlint-maven-plugin

Projects to add this :

• reactor-dto-validator
• pet-commands
• command-producer-consumer

[FEATURE] Retry and Failure

Describe the feature
When we listen to messages from Kafka we will need to handle retries and failures

[FEATURE] Add ktlint to pet-stream service

Describe the feature
Add the ktlint tool to format and verify the code

[FEATURE] Create pet-stream service

Describe the feature
Create the new pet-stream service.

[BUG] Change diagram

Describe the bug
The name of the services is wrong.

Additional context
The correct names of the services are: pet-commands, pet-stream and pet-queries.

[FEATURE] Error handling in pet-queries

Describe the feature
We should handle errors and return json messages.

[FEATURE] Add a Diagram for the Domain Mode

Describe the feature
We need a diagram that shows the domains for our application

[FEATURE] Upgrade depencies

Describe the feature
Update dependencies for:

• dto-validator
• comand-producer-consumer
• pet-commands
• pet-streams

Additional context

• spring-boot-starter-parent : 2.3.2.RELEASE
• test-containers: 1.14.3

[FEATURE] allow to configure the CommandsConsumer to have a timeout

Describe the feature
When we use the CommandsConsumer if Kafka is not available we will wait forever.

Additional context
We should be able to configure how long we will wait that is available before subscribing to get commands.

[FEATURE] add diagram for the pets domain architecture

Describe the feature
We need to create a diagram that shows the Pets domain architecture

[FEATURE] Create the command producer-consumer library

Describe the feature
Create a library to produce and consume command messages from a Kafka queue using reactor.

[FEATURE] Create pet-queries service

Describe the feature
Create the pet-queries service with its dependencies:

• R2DBC
• PostgresQL
• Webflux
• Ktlint plugin

[FEATURE] improve working with list ussing commands

Describe the feature
Improve the usage on list with commands

Additional context
Commands allows to work with list, we could do :

val command = command("example command") {
        "attribute1" value listOf("one", "two", "three")
 }

val list = command.get<List<String>>("attribute1")

However this is not working very will if we do this

val command = command("example command") {
        "attribute1" value listOf("one", "two", "three")
 }

val list = command.get<List<Int>>("attribute1")

Even if we have specified to return a List<Int> we will get a List<String> since the type assurance is just in List.

We need a new function to do that, something like

val command = command("example command") {
        "attribute1" value listOf("one", "two", "three")
 }

val list = command.getList<Int>("attribute1")

Them we could raise failures if we can not get that kind of list.

Finally we could make a new dsl infix named values to make it more clear that we are setting a List in our attribute.

[FEATURE] Install postgreSQL in kubernetes

Describe the feature
We have to install and configure a postgreSQL database in Kubernetes

[FEATURE] Move master branch to main

Describe the feature
We need to move the master branch to main

Additional context
See this link :
https://www.hanselman.com/blog/EasilyRenameYourGitDefaultBranchFromMasterToMain.aspx

[FEATURE] Upgrade spring version to 2.3.1

Describe the feature
We should upgrade the spring version to use the latest one.

• command-producer-consumer
• pet-commands
• reactor-dto-validator

[FEATURE] Add new pet

Describe the feature
We have to implement the post request to add a new pet in the store.

• This feature should generate a command to perform the pet creation.

Additional context
https://petstore.swagger.io/#/pet/addPet

[FEATURE] Create service component to process commands and save pets in a database

Describe the feature
We have to create a new service component so that we can process commands and save pets in a postgresql database

[BUG] Error creating database cluster

Describe the bug
When launching the service that set up all the infrastructure, we get an error creating the database cluster when the operator installation takes too much time.

To Reproduce
Steps to reproduce the behaviour:

1. Run the service with go run
2. Check the logs to see the error
3. See error
   Error running the set up, error installing database, error creating database cluster "petstore-pets-cluster": error 'exit status 1' in "/usr/local/bin/kubectl" "error: unable to recognize "pets-db.yml": no matches for kind "postgresql" in version "acid.zalan.do/v1"\n"

Expected behaviour
The database cluster should be created without errors.

[FEATURE] Refactor to use transactions during pets creation

Describe the feature
Currently we are manually rollbacking when failure creating a pet. We should change this in order to use transactions so that the rollback happens automatically.

Additional context
https://docs.spring.io/spring-data/r2dbc/docs/1.0.x/reference/html/#r2dbc.datbaseclient.transactions

[FEATURE] adding timeout configuration to the producer

Describe the feature
Currently, when we send a command we will wait forever to the broker been available, we need somehow been able to specify a timeout for sending the command.

Additional context
Probably a setting in the CommandsProducerConfig we will be required

Setup Github Project

We need to set-up the Github Project, we need :

• Readme
• Code of Conduct
• Projects
• Tags