Mohammad Waseem

Posted on Feb 3

Zero-Budget Kubernetes: Automating Authentication Flows Without Breaking the Bank

#kubernetes #devops #automation

Automating Authentication Flows on a Zero Budget Using Kubernetes

In modern software development, seamless and secure authentication flows are critical, especially for microservices-based architectures. However, not every team has the luxury of budget to incorporate expensive third-party identity providers or commercial solutions. As a seasoned DevOps specialist, I’ve faced the challenge of implementing automated, secure auth flows on a zero-budget setup—mainly leveraging free, open-source tools and Kubernetes' native capabilities.

The Challenge

The goal is to create a lightweight, scalable, and automated authentication process within Kubernetes that can handle user sign-in, token management, and dynamic identity flow without external paid services. This approach must work with minimal resources and avoid relying on external cloud-based identity providers.

The Approach

The core idea involves self-hosted solutions, leveraging Kubernetes features, and open-source tools for identity and secret management. Key components include:

OAuth2 Proxy: As an open-source reverse proxy that provides OAuth2 authentication and cookie-based session management.
JWT tokens: For secure token handling and stateless session management.
Kubernetes Secrets: To securely store credentials and tokens.
Ingress Controller: To route external requests and integrate with OAuth2 Proxy.

Implementation Steps

1. Deploy OAuth2 Proxy

OAuth2 Proxy allows integrating with various identity providers or custom authentication systems. Here, we'll configure it with a basic self-managed identity system, such as a simple username-password database.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: oauth2-proxy
spec:
  replicas: 1
  selector:
    matchLabels:
      app: oauth2-proxy
  template:
    metadata:
      labels:
        app: oauth2-proxy
    spec:
      containers:
      - name: oauth2-proxy
        image: quay.io/oauth2-proxy/oauth2-proxy:latest
        ports:
        - containerPort: 4180
        args:
        - --provider=generic
        - --http-address=0.0.0.0:4180
        - --client-id=YOUR_CLIENT_ID
        - --client-secret=YOUR_CLIENT_SECRET
        - --cookie-secret=YOUR_COOKIE_SECRET
        - --upstream=http://your-backend-service:80
        - --email-domain=*
        - --cookie-secure=false
        - --skip-provider-button=true

2. Configure Ingress Route

Set up an NGINX ingress (or any other ingress controller) to route external traffic through OAuth2 Proxy.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: app-ingress
  annotations:
    nginx.ingress.kubernetes.io/auth-url: "http://oauth2-proxy.default.svc.cluster.local:4180/auth"
    nginx.ingress.kubernetes.io/auth-signin: "http://oauth2-proxy.default.svc.cluster.local:4180/start"

spec:
  rules:
  - host: yourdomain.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: your-backend-service
            port:
              number: 80

3. Secure Secret Management

Kubernetes Secrets hold sensitive information such as API keys and secrets for OAuth2 (client secrets, cookie secrets).

kubectl create secret generic oauth2-secrets \
  --from-literal=client-id=YOUR_CLIENT_ID \
  --from-literal=client-secret=YOUR_CLIENT_SECRET \
  --from-literal=cookie-secret=$(openssl rand -base64 32)

And reference these in your OAuth2 proxy deployment via environment variables.

4. Custom Authentication Backend

Without external services, implement a simple username-password verification system using an internal database or environment variables, or even leveraging ConfigMaps for prototyping. For production, consider integrating with LDAP or an external identity directory hosted internally.

apiVersion: v1
kind: ConfigMap
metadata:
  name: auth-db
data:
  users: |
    alice:password123
    bob:securepass

5. Automate and Extend

Leverage Kubernetes’ native capabilities like Horizontal Pod Autoscaler, ConfigMaps, and Secrets for scaling and automation, and set up CI/CD pipelines to update credentials and configurations automatically.

Final Thoughts

Implementing authentication flows in Kubernetes on a zero budget is achievable by harnessing free and open-source tools combined with Kubernetes’ native features. This approach emphasizes self-hosted, lightweight components, and secure secret management. While it requires careful configuration and security considerations, it provides a resilient, flexible, and cost-effective solution to automate auth flows in your Kubernetes environment.

Moving forward, consider augmenting this setup with custom sidecars for enhanced security, audit logging, and advanced identity federation, all without incurring additional costs, ensuring your cluster remains agile and secure at minimal resource expenditure.

Tags: devops, kubernetes, automation

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