Helmfile is a declarative tool for managing Kubernetes Helm releases across multiple environments. It defines the desired state of releases in version-controlled YAML files and synchronizes the cluster to match that state, acting as both a release manager and a state sync orchestrator. The tool layers environment-specific values, secrets, and lifecycle hooks onto shared release definitions, enabling consistent multi-environment deployments.
Helmfile distinguishes itself through several integrated capabilities: it generates separate dependency lockfiles per environment for staged rollout of chart updates, and it runs user-defined commands at configurable points before and after sync operations to customize deployment workflows. Secrets are injected from external stores like Vault or AWS SSM via plugins, and the tool supports GitOps workflows by rendering manifests for review and automated synchronization. Modular configuration patterns can be packaged into reusable modules distributed through Git or S3, and helmfile includes periodic automation for updating chart versions and reconciling cluster state.
The tool provides a Go template rendering pipeline with helper functions for collection manipulation, data transformation, math, and IP subnet calculation. It supports layered YAML composition, external value sourcing from shell commands or remote URLs, pre-install patching of charts and resources, and deployment from OCI-compliant registries. Release operations include label-based selection, change previews with diff tools, dependency visualization, and validation steps such as linting and chart testing.
