eventflow-example

eventflow showcase project

This is an example of usage of eventflow and implementation of event sourcing pattern in go.

Payments HTTP REST API (json) implemented using CQRS and Event Sourcing pattern.

CQRS gives us separation of concerns for our writes and reads. This way we can easily scale traffic for creations and queries independently.

Event Sourcing gives us all information about changes that happened in our service. This way we've got detailed view what's changes in our system (audit log). We can create state at particular time if needed or re-apply from beginning to get current state

Notice

This demo does not implement all unit and/or integration/e2e tests. Some of them are just for showing of how the may look like.

How to run

Command part uses postgres as underlying storage. Run docker image:

docker run --rm --name es-postgres -d -e POSTGRES_DB=events -e POSTGRES_USER=usr -e POSTGRES_PASSWORD=pwd -p 5432:5432 postgres:11.2

Query part uses mongodb as underlying storage. Run docker image:

docker run --rm --name es-mongo -d -e MONGO_INITDB_ROOT_USERNAME=usr -e MONGO_INITDB_ROOT_PASSWORD=pwd -p 27017:27017 mongo:3.4

Build and run

# build
$ go build
# run 
$ ./eventflow-example

Payments REST API

Command Part

# returns 'id' in response header: 'Location'
curl -X POST http://localhost:8080 -d '{"type":"instant", "attributes":{"amount":"100.50","currency":"EUR","beneficiary_party":{"account_name":"Ben","account_number":"123"},"debtor_party":{"account_name":"Deb","account_number":"987"},"payment_id":"92aaf311-a2fe-4022-86ef-162f314149df","payment_type":"credit_card","processing_date":"2019-03-13T21:20:57+01:00","reference":"f1eef151-87c0-4aac-afbc-3e68c8f5807c"}}' -v

curl -X PUT http://localhost:8080/7db061e8-81c5-499d-9f93-321cde3575be/beneficiary-party -d '{"account_name":"Mr. Ben","account_number":"123456789"}' -v

curl -X PUT http://localhost:8080/7db061e8-81c5-499d-9f93-321cde3575be/debtor-party -d '{"account_name":"Account Inc.","account_number":"987654321"}' -v

curl -X DELETE http://localhost:8080/7db061e8-81c5-499d-9f93-321cde3575be -v

Query Part

curl -X GET http://localhost:8081/7db061e8-81c5-499d-9f93-321cde3575be -v

# use query 'page' and 'limit' for paging
curl -X GET http://localhost:8081?page=1&limit=10 -v