GitOps and Continuous Delivery

GitOps and Continuous Delivery is a practical engineering guide to using Git as the single source of truth for Kubernetes deployments. It starts from a single observation: the question "what is actually deployed in production, and who put it there?" used to have no clean answer, and GitOps makes it a lookup in the commit history. The book walks through the full discipline — the case for GitOps and the specific problem it solves, the four principles that define the model, Git repository structures and promotion workflows at scale, reconciliation loops and the controller patterns that implement them, Argo CD and Flux in depth, progressive delivery with canary and blue-green releases, the secrets problem and the patterns that solve it, multi-environment and multi-cluster GitOps, policy enforcement and drift detection, observability for the GitOps process itself, migration from imperative CI/CD, supply chain security, and the trends reshaping the field. It covers the failure modes that quietly wreck GitOps installations: a reconciliation loop that fights a legitimate manual change during an incident, a secret committed in plaintext because the developer did not realise the repository was public, an ApplicationSet that generates hundreds of orphaned applications after a template change, a drift that is silently pruned because the manifest was accidentally deleted, a canary analysis that promotes a broken release because the metric was not sensitive enough, a bootstrap procedure that fails halfway and leaves the cluster in an inconsistent state. Each is presented with the failure, the countermeasure, and the operational tradeoff.