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Running Preflight Checks for Helm Installations

You can run Helm preflight checks before running helm install and during the installation of an application. Additionally, your preflight checks can include one or more specification types and resources.

Prerequisite​

Customers must install the preflight plug-in, which is a client-side utility that adds a single binary to their path.

To install the preflight plug-in:

  1. Log in to the registry where the Helm chart and preflight specification were pushed to:

    helm registry login REGISTRY_DOMAIN --username USERNAME --password PASSWORD

    Replace:

    • REGISTRY_DOMAIN with the registry domain that contains the Helm chart.
    • USERNAME with the username that has access to the registry.
    • PASSWORD with the password for the registry.

  2. Run the following command to install the preflight plug-in using krew:

    curl https://krew.sh/preflight | bash

Run Preflight Checks​

Before running the helm install command, your customers run the preflight checks to verify that their environments meet the installation requirements before they run the actual installation.

The output shows the success, warning, or fail message for each preflight check, depending on how they were configured. You can ask customers to send you the results of the preflight checks if needed.

  • To run the basic preflight command:

    helm template oci://REGISTRY/APP_NAME/CHANNEL/CHART | kubectl preflight -

  • If preflight checks are dependent on customer values, run the preflights using the values file to override chart defaults:

    helm template oci://REGISTRY/APP_NAME/CHANNEL/CHART --values FILENAME.yaml | kubectl preflight -

    Replace:

    • REGISTRY with the registry domain where your Helm chart is located. This can be the Replicated registry or a custom domain.
    • APP_NAME with the name of the application.
    • CHANNEL with the release channel.
    • CHART with the name of the Helm chart.
    • FILENAME with the name of the values file.