Small business: microservices

Project description

Create a single API that seamlessly exposes the data of three different systems: Warehouse, Accounting, Sales. The system should be available 24/7, scalable, resilient to failures, and the data should be available through different offices around the world.

Mian requirements

~~Design the architecture of the new system and explain your reasons to use it~~
~~Code at least three microservices with the best code quality possible and expose them via a REST API~~
~~The software artifacts should be covered by unit tests~~
~~The software artifacts should be easy to package and deploy~~

Extra requirements

~~Provide any document or diagram useful to explain your proposal~~
Applications covered by acceptance tests suites
~~Define the software technologies that should be used to build a system that’s scalable, reliable, and distributed.~~
Describe your ideal development workflow considering stability, security, and agility from the beginning.
Define a versioning policy and a strategy to deploy in production
Automatically generated documentation
Mention the software technologies to build your ideal CI/CD environment
~~Fully functional CI workflow~~
Fully functional CD workflow

Design

Stack: Python, Django, Postgres, Kubernetes, NGINX

Why Django? Personal curiosity, because I've never worked with it.

Why Kubernetes? Kubernetes allows easily scale services and make clear intra-service communication.

Why Postgres? This is the most common enterprise DB solution.

Why NGINX? It provides the ability to run API Gateway in Kubernetes Cluster

What is planned to be Done:

The whole system is supposed to be deployed in a Kubernetes cluster and have cluster API Gateway to all the services.

What is Done at the moment

Service	Deploy
Each service has several layers, which are flexible to extend and replace.	Each service(django project) has the following files to be able to work with other services within a Kubernetes cluster:

Intra-service communication

At the moment, the is only one intra-service communication between Sales and Warehouse which is accessible via the following endpoint:

curl "http://<GATEWAY_IP>:<GATEWAY_PORT>/sales/sold_items"

Running services under Docker:

This will run 3 separate services with databases

sh small_business_ms/k8s/run_services.sh

Use warehouse.init_data.sql, accounting.init_data.sql and sales.init_data.sql scripts to fill in some data (I'm using DBeaver)
Use the corresponding Postman collections to run.

Local Cluster setup:

You may use any local kubernetes services you like, but this project was run under Docker Desktop Kubernetes. Do the following steps to use it:
1. From the Docker Dashboard, select the Settings.
2. Select Kubernetes from the left sidebar.
3. Next to Enable Kubernetes, select the checkbox.
4. Select Apply & Restart to save the settings and then click Install to confirm.
  
  More information about Kubernetes under Docker Desktop you may find following the link.
Please, make sure you have kubectl installed. If not, use the instructions to install
Using git bash or terminal(macOS) run the following commands:
1. Choose a directory you want to clone a project and run:
```
git clone git@github.com:BarabanovaIrina/small_business_ms.git
```
1. Without changing the directory run build all services necessary images:
```
sh small_business_ms/k8s/build_images.sh
```
1. Build NGINX API Gateway and enable port forwarding:
```
sh small_business_ms/k8s/deploy_all.sh
```
1. If you face issues like Internal error occurred, please, run the previous step again. That might happen when parts take some time to deploy.
2. As a final result you should see port forwarding messages:
```
Forwarding from 127.0.0.1:8080 -> 80
Forwarding from [::1]:8080 -> 80
Forwarding from 127.0.0.1:8443 -> 443
Forwarding from [::1]:8443 -> 443
```

There is a Postman collection with all the available(at the moment) requests you may test.

What is yet to be Done:

~~Replace dummy Dict database with a real Postgres database~~
~~Extend CRUD for other services~~
Come up with a scenario of using message bus in intra-service communication
~~Create CD pipelines~~
Add auto-documentation
Fix imports in test or divide services into separate repositories

BarabanovaIrina/small_business_ms