Best Practices for Azure Containers

This document outlines recommended best practices for deploying, managing, and optimizing containerized applications on Azure. Adhering to these guidelines will help you build scalable, secure, and cost-effective container solutions.

1. Image Optimization

Efficient container images are crucial for faster deployments and reduced resource consumption.

• Minimize Image Size: Use multi-stage builds to copy only necessary artifacts from the build stage to the runtime stage.
• Use a .dockerignore File: Exclude unnecessary files and directories from being copied into the image build context.
• Choose Lightweight Base Images: Opt for minimal base images like Alpine Linux or Distroless.
• Scan Images for Vulnerabilities: Integrate image scanning tools (e.g., Azure Container Registry's vulnerability scanning, Trivy, Clair) into your CI/CD pipeline.

2. Security

Security must be a primary consideration throughout the container lifecycle.

2.1. Image Security

• Secure Base Images: Use trusted and regularly updated base images from reputable sources.
• Least Privilege Principle: Run containers as non-root users whenever possible. Configure the USER instruction in your Dockerfile.
• Secrets Management: Never hardcode secrets (passwords, API keys) in container images. Use Azure Key Vault, Kubernetes Secrets, or managed identity for secure access.

2.2. Runtime Security

• Network Segmentation: Use network policies (in Kubernetes) or virtual network rules to restrict communication between containers and external services.
• Resource Limits: Define CPU and memory limits for your containers to prevent resource starvation and denial-of-service attacks.
• Runtime Security Tools: Consider tools like Aqua Security or Falco for advanced runtime threat detection.

3. Orchestration and Management

Leverage Azure's orchestration services for robust container management.

3.1. Azure Kubernetes Service (AKS)

• Automate Deployments: Use Helm charts or Kubernetes manifests for declarative deployments and easy management.
• Implement Autoscaling: Configure Horizontal Pod Autoscaler (HPA) and Cluster Autoscaler to dynamically adjust resources based on demand.
• Health Probes: Implement liveness and readiness probes to ensure containers are healthy and ready to serve traffic.
• Use Managed Identities: Grant AKS workloads managed identities to securely access other Azure resources.

3.2. Azure Container Instances (ACI)

• Simplify Serverless Containers: Use ACI for simple container deployments, batch jobs, or event-driven scenarios where full orchestration is not needed.
• Secure Network Access: Configure VNet integration and private endpoints for secure access to your ACI instances.

4. Networking

Design your container networking with scalability and security in mind.

• Choose the Right Networking Plugin: For AKS, select an appropriate network plugin (e.g., Azure CNI for direct VNet integration).
• Ingress Controllers: Use an Ingress controller (like Nginx or Traefik) to manage external access to your services, handle SSL termination, and provide load balancing.
• Service Discovery: Rely on the orchestration platform's service discovery mechanisms (e.g., Kubernetes Services).

5. Monitoring and Logging

Gain visibility into your containerized applications.

• Centralized Logging: Forward container logs to a centralized logging solution like Azure Monitor Logs (Log Analytics) or Elasticsearch.
• Application Performance Monitoring (APM): Integrate APM tools (e.g., Application Insights) to trace requests, identify bottlenecks, and monitor application health.
• Metrics Collection: Collect key metrics (CPU usage, memory, network traffic, request latency) and set up alerts for anomalies.

6. Cost Optimization

Manage your Azure container costs effectively.

• Right-size Resources: Continuously monitor resource utilization and adjust CPU and memory requests/limits to avoid over-provisioning.
• Utilize Spot Instances: For fault-tolerant workloads, consider using AKS node pools with Spot VMs to significantly reduce compute costs.
• Clean Up Unused Resources: Regularly remove unused images, containers, and associated resources.