Kubernetes for Application Developers

Kubernetes is the de facto container orchestration platform. For many application developers, the goal is not to manage clusters but to write reliable manifests, understand lifecycle hooks, and use platform standards (Helm charts, GitOps) to ship safely.

Core concepts

• Pod: the smallest deployable unit that runs one or more containers.
• Deployment: declarative updates for pods.
• Service: stable network endpoint for a set of pods.
• ConfigMap/Secret: configuration and secret storage for apps.
• Namespace: logical partitioning within a cluster.

Local development and CI

• kind and k3d are fast, container-based local clusters suitable for CI.
• Keep manifests small in dev and use partial overrides for production configs.

Deployments and update strategies

• Rolling updates are the default; consider canary or blue/green for safer rollouts.
• Use readiness probes to prevent traffic to warming pods, and liveness probes to recycle unhealthy containers.

Example readiness probe (HTTP):

readinessProbe:
  httpGet:
    path: /health
    port: 8080
  initialDelaySeconds: 5
  periodSeconds: 10

Configuration and secrets

• Keep secrets in Kubernetes Secret objects or integrate with external secret stores (Vault, AWS Secrets Manager) via CSI drivers.

Packaging and Helm

• Use Helm charts or Kustomize to templatize deployments. Publish charts in an internal registry for reuse.

Observability and troubleshooting

• Ship application metrics (Prometheus), logs (Fluentd/Fluent Bit → central store), and traces (Jaeger/OTel).
• Use kubectl describe and kubectl logs for quick debugging; rely on dashboards for historical context.

Security

• Run containers with minimal privileges and set PodSecurityPolicies or the newer Pod Security Admission.
• Use NetworkPolicies to limit east-west traffic.

Internal links

• Docker primer: Docker Basics for Developers
• Pillar: Practical Cloud Computing for Developers
• Related: Getting Started with Google Cloud Platform (GCP) for Developers
• Related: CI/CD in the Cloud

References

• Kubernetes docs: https://kubernetes.io/docs/home/
• Helm: https://helm.sh/

Related articles

GitOps workflows for Kubernetes clusters