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Preview and Deploy Native Helm Value Overrides

· 2 min read
Erik Osterman
Erik Osterman
Founder @ Cloud Posse

An urgent image rollback, a temporary feature flag, or a one-off chart setting should not require editing a stack manifest just to make one deployment. Yet a preview is only useful when it renders the exact values that the later deployment will use. When temporary values live in a shell wrapper or are applied only at deploy time, teams cannot reliably see the change before it reaches a cluster.

The Problem​

Native Helm components already resolve chart values from inherited stack configuration, component value files, and inline values. Before this update, there was no Helm-compatible command-line override surface for those resolved values. Operators had to commit a temporary configuration change, use a separate wrapper around Helm, or accept that a diff did not necessarily match the subsequent deployment.

The Fix​

Native Helm now accepts repeatable Helm-compatible -f/--values, --set, --set-string, --set-file, --set-json, and --set-literal flags on template/render, diff/plan, and apply/deploy. The overrides apply only to the current invocation and take precedence over the resolved component values; they never modify stack configuration.

The new atmos helm values command prints the final, masked value map as formatted YAML. It lets you inspect the value set that a preview or deployment will consume, including temporary command line overrides, without contacting Kubernetes.

How to Use It​

Use the same override arguments for inspection, preview, and deployment:

atmos helm values monitoring -s plat-ue2-dev \
  -f incident-values.yaml \
  --set image.tag=2026.09.09

atmos helm diff monitoring -s plat-ue2-dev \
  -f incident-values.yaml \
  --set image.tag=2026.09.09

atmos helm apply monitoring -s plat-ue2-dev \
  -f incident-values.yaml \
  --set image.tag=2026.09.09

Atmos layers command-line value files and each supported --set variant over the component's resolved values using Helm's normal parsing and precedence rules. That includes nested paths, list indexes, typed values, string and literal handling, JSON input, and file-backed values.

Get Involved​

See the native Helm command reference for the complete override reference and the values command guide. Have feedback? Open an issue or join the Cloud Posse community Slack.