A detailed walkthrough of migrating legacy Drupal 8 PHP monolith websites to Kubernetes, covering the full journey from Dockerfile creation and Helm charts to static asset handling with NFS, Redis and Nginx caching layers, PHP-FPM-based autoscaling with HPA, CronJob isolation on dedicated nodes, and a multi-Ingress DDoS protection architecture. The post also compares total cost of ownership between the legacy and Kubernetes-based setups, noting that infrastructure costs remain similar but maintenance costs rise while reputational risk drops significantly.
Table of contents
Why move a monolith to Kubernetes?Architecture of a typical monolithMigrating to KubernetesImproving Drupal performanceAdding autoscaling to reduce infra costsConfiguring cron jobs in KubernetesProtecting from DDoS attacksConclusion42 Impressions