Migrating charts from HELM v2 to v3 seems to be pretty straight forward for environments having minimal charts and revisions. Consider yourself managing clusters with large volume of deployed applications across multiple environments, here comes migration plan to be prepared and approved.

Backup! Backup!

If you are an ops engineer and before making any changes it is an thumb rule to backup. Backing up HELM charts is pretty easy using Velero tool. Refer commands to backup and restore charts just in case if things goes south. It has cloud including community supported providers to store backup charts.

Migrate chart

HELM provides an plugin to migrate chart from v2 to v3 named 2to3. Major functionality of the plugin is to convert chart to v3, but has other three required tasks

• version 2 Configuration migration
• version 2 Release cleanup
• Tiller cleanup

Migrating to HELM3 involves script changes to your CD pipelines. Release pipelines has reference to tiller namespace, environment will need HELM3 installed with configuration migrated and HELM v3 command mandates namespace while deploying charts to cluster. Synchronization of migrating your charts and updating pipeline stage script is the key. There could be situations if you have migrated the chart and not updated pipeline script, HELM 2 charts will be added after last migration baseline release. Now we can reset baseline again by converting chart to v3 but by skipping releases including previous baseline converted chart.