Argo CD GitOps Continuous Delivery

Overview

Declarative GitOps CD for Kubernetes: Git is the source of truth, a controller reconciles cluster state toward it. Vocabulary you must be exact about: target state (Git), live state (cluster), sync (make live match target), OutOfSync (they differ), health (per-resource readiness, distinct from sync), refresh (recompare Git vs live), AppProject (RBAC/resource boundary grouping Applications).

Two facts that trip up most newcomers, stated up front:

• OutOfSync ≠ unhealthy, and Healthy ≠ InSync. They are orthogonal axes. A perpetually-OutOfSync-but-Healthy app almost always means a controller mutates a field after apply — fix with ignoreDifferences (see Expert Practices), not by re-syncing.
• Argo CD only inflates manifests (helm template, kustomize build) — it never runs helm install. helm ls/helm rollback show nothing.

When Argo CD vs Flux

Both are CNCF-graduated GitOps controllers; the choice is architectural, not feature-parity.