Laboratory Works on Distributed Systems Programming

Description

E-commerce platform that allows users to buy and sell products. This idea's implementation through distributed systems is suitable because it can be easily separated in distinct components that can be developed independently. Similar platforms that use microservices architecture are Amazon, eBay, AliExpress, etc.

Run Application with Docker

More information about Docker.
To run the application type this command in the root folder.

$ docker compose up

You might have to run this command twice if it doesn't work the first time :)

Run Application with Kubernetes

More information about Kubernetes. Before running next commands move to k8s directory.

$ cd ./k8s

First of all you need to start Redis cluster which will take some time.

$ kubectl apply -f ./redis-cluster.yaml

After that you can use these two commands to check if the cluster has been initialized correctly.

$ kubectl exec redis-cluster-0 -- redis-cli cluster nodes
$ kubectl exec redis-cluster-0 -- redis-cli --cluster check localhost 6379

To start Postgres cluster we'll be using Kubegres.
First we have to install Kubegres Custom Resource Definitions.

$ kubectl apply -f https://raw.githubusercontent.com/reactive-tech/kubegres/v1.17/kubegres.yaml
$ kubectl get all -n kubegres-system

Then we can start Postgres cluster which may take some time.

$ kubectl apply -f postgres-cluster.yaml

To run everything else type these commands one by one in this exact order.

$ kubectl apply -f ./rabbitmq.yaml
$ kubectl apply -f ./postgres.yaml
$ kubectl apply -f ./services.yaml
$ kubectl apply -f ./gateway.yaml

For performance monitoring we'll be using Prometheus Operator.
The first step is to install the operator's Custom Resource Definitions as well as the operator itself with the required RBAC resources.

LATEST=$(curl -s https://api.github.com/repos/prometheus-operator/prometheus-operator/releases/latest | jq -cr .tag_name)
curl -sL https://github.com/prometheus-operator/prometheus-operator/releases/download/${LATEST}/bundle.yaml | kubectl create -f -

To start Prometheus run the following command.

$ kubectl apply -f ./prometheus-operator.yaml

Cleanup Kubernetes Resources

To delete created resources type these commands.

$ kubectl delete -f ./prometheus-operator.yaml
$ kubectl delete -f ./gateway.yaml
$ kubectl delete -f ./services.yaml
$ kubectl delete -f ./postgres.yaml
$ kubectl delete -f ./rabbitmq.yaml
$ kubectl delete -f ./redis-cluster.yaml
$ kubectl delete kubegres warehouse

To also delete Kubegres Custom Resource Definitions.

$ kubectl delete -f https://raw.githubusercontent.com/reactive-tech/kubegres/v1.17/kubegres.yaml

I don't know how to remove Prometheus Operator.

Use the Application

0. Run the application as mentioned above.
1. Access Swagger UI at localhost:3010/api.
2. Register a user with the POST /users/register endpoint.
3. Login with the POST /users/login endpoint. (optional)
4. Copy the access token from the response body.
5. Set the access token in the Authorize button from the top right corner of the Swagger UI.
6. Create a product with the POST /products endpoint.
7. Order a product with the POST /orders/:productId endpoint.

You can find the internal endpoints specification in /proto folder.

Monitor the Application

0. Access Prometheus at localhost:9090.
1. Access Grafana at localhost:3000.
2. Login using credentials: admin and password.
3. Open the Dashboards tab from the left side menu.
4. Select Microservices Metrics dashboard.

System Architecture Diagram

Redis Cluster Diagram

Postgres Cluster Diagram