Kubernetes Flask PostgreSQL Dashboard

This project demonstrates how to:

1. Create a Kubernetes namespace.
2. Provision a Flask app and PostgreSQL database in the namespace.
3. Automatically fetch and store running pod names in the PostgreSQL database.

---

Prerequisites

• Kubernetes cluster (e.g., Minikube, Kind, or a cloud-based cluster)
• Docker
• kubectl
• Python 3.x

---

Setup

1. Clone the Repository

Clone this repository to your local machine:

git clone https://github.com/your-username/kubernetes-flask-postgres.git
cd kubernetes-flask-postgres

2. Apply Kubernetes Manifests

Apply the Kubernetes manifests to create the namespace, pods, and services.

Create the Namespace

Create the nrp namespace:

kubectl apply -f namespace.yaml

Deploy the PostgreSQL Database

Deploy the PostgreSQL pod and service:

kubectl apply -f postgres-pod.yaml
kubectl apply -f postgres-service.yaml

Deploy the Flask App

Deploy the Flask app pod and service:

kubectl apply -f flask-pod.yaml
kubectl apply -f flask-service.yaml

Set Up RBAC (Role-Based Access Control)

Grant the Flask app permission to list pods in the nrp namespace:

kubectl apply -f pod-reader-role.yaml
kubectl apply -f pod-reader-rolebinding.yaml

3. Access the Flask App

Use kubectl port-forward to access the Flask app locally.

Port Forwarding

Forward port 5000 from the flask-app pod to your local machine:

kubectl port-forward pod/flask-app -n nrp 5000:5000

Test the /pods Endpoint

Fetch the list of running pods: You can also use Postman to test this route after port forwarding This route does not give us pods that we store in our database through store-pods..This only gives the list of running pods on our namespace..This is because we can store pods in our databse that might not even be running on our namespace...

curl http://localhost:5000/pods

Expected Response:

["flask-app", "postgres-db"]

Test the /store-pods Endpoint

Before doing this first create table:

kubectl exec -it postgres-db -n nrp -- psql -U admin -d nrp_db
CREATE TABLE pods (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL
);
\dt

Store pod names in the PostgreSQL database: You can also use postman for this

curl -X POST http://localhost:5000/store-pods -H "Content-Type: application/json" -d "{\"pod_names\": [\"flask-app\", \"postgres-db\"]}"

Expected Response:

{"message": "Pod names stored successfully"}

4. Verify Data in PostgreSQL

Connect to the PostgreSQL pod and query the pods table to confirm the data was stored.

Connect to PostgreSQL

kubectl exec -it postgres-db -n nrp -- psql -U admin -d nrp_db

Query the pods Table

SELECT * FROM pods;

Expected Output:

 id |    name
----+------------
  1 | flask-app
  2 | postgres-db
(2 rows)