nacrITan, the project :

This project is a backend for a Tactical Interface (IT) in the game Nacridan.
Its purpose is to parse data received from JS user scripts.
It's done by a Python backend (Flask API) querying a MongoDB.

All of this inside Docker containers for portable purposes.
These containers are powered up by Kubernetes.

Actually, it works this way :

(nacritan-nginx) runs the proxy to serve the URLs, and SSL certs
(nacritan-api) runs the Flask app

Optionnal:

(nacritan-backup) runs the DB rotating backups 24h/30d/52w/12m

Which script does what ?

.
├── k8s                               |  
│   ├── deployment-*.yaml             |  Pods deployment files
│   └── service-*.yaml                |  Services deployment files
└── code                            |  
    ├── tests
    │   ├── test_00_vars.py           |  Tests for token presence
    │   ├── test_01_auth.py           |  Tests for token auth by routes
    │   └── test_02_data.py           |  Tests for data returned by routes
    └── app.py                        |  Flask main app

Tech

I used mainy :

docker/docker-ce to make it easy to maintain
kubernetes/kubernetes to make everything smooth
Alpine - probably the best/lighter base container to work with
pallets/flask - Python micro framework for building API
pytest-dev/pytest - Python test framework

And of course GitHub to store all these shenanigans.

Schematics

     +-----------------------------------------------+
     |                  NodePort:30443               |
     +-----------------------+-----------------------+
                             |
                    +--------v--------+
                    |    nginx:443    |
                    +--------+--------+
                             |
                    +--------v--------+
                    |    Flask:5000   |
                    |     (app.py)    |
                    +--------+--------+
                             |
                    +--------v--------+
                    |  Ext.  MongoDB  |
                    +-----------------+

Installation

The core and its dependencies are meant to run in a Docker/k8s environment.
Could work without it, but more practical to maintain this way.

Every part is kept in a different k8s file separately for more details.

$ git clone https://github.com/lordslair/nacritan
$ cd nacritan/k8s
$ kubectl apply -f *

This will create :

The pods : nginx, api (+ backup if needed)

$ kubectl get pods
NAME                       READY   STATUS    RESTARTS       AGE
api-769b969d98-rgmk4       1/1     Running   0              95d
backup-cdddf5787-5742g     1/1     Running   0              95d
nginx-5cc68db8d7-rchxb     2/2     Running   0              33m

The 2 volumes : certbot-certs, certbot-www

$ kubectl get pvc
NAME               STATUS  VOLUME                   CAPACITY  [...]
certbot-certs-pvc  Bound   pvc-[...]-5312025190d9   1Gi       [...]
certbot-www-pvc    Bound   pvc-[...]-d6ab9d74cf8b   1Gi       [...]

The 3 services : nginx, api

$ kubectl get services
NAME          TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)                      AGE
api-svc       ClusterIP   10.3.223.39    <none>        5000/TCP                     155d
nginx-svc     NodePort    10.3.140.182   <none>        80:30080/TCP,443:30443/TCP   31m

Disclaimer/Reminder

The project is not mono-container, but could. Minimal setup would be one pod (Flask app without nginx).

Todos

Add a container for Discord integration