Reinstalling the same version

The install_asm script calls istioctl install to deploy the Anthos Service Mesh control plane components (istiod and istio-ingressgateway) for installs, upgrades, and Istio migrations. Because the script uses istioctl install, if you need to customize Anthos Service Mesh to enable an optional feature, you have to reinstall the control plane with the new configuration.

A change was made to the install_asm script so that you can reinstall the same version of Anthos Service Mesh. When you reinstall the same version to enable an optional feature, the existing control plane configuration is overwritten. Because of this, if you customized the existing installation, you need to include the same --option and/or --custom_overlay options from from the previous installation and the --option and/or --custom_overlay options for the feature(s) that you want to enable or configure.

If you specify more than one IstioOperator custom resource (CR) in a YAML file, install_asm splits the file into multiple temporary YAML files, one for each CR. The script splits the CRs into separate files because istioctl install only applies the first CR in a YAML file containing more than one CR.

When you reinstall the same version, you specify --mode install just like for new installations. For information on installing using the script, see Installing Anthos Service Mesh.

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