Upgrading Pulumi Providers

The Principle

A provider upgrade is a translation, not a change request.

The user's infrastructure intent hasn't changed - they still want the same bucket, the same function, the same cluster. What changed is how the provider's API expresses that intent. Your job is to translate their existing code into the new API so that Pulumi sees no difference between what the code says and what already exists.

There are four layers to keep in mind:

1. User intent - what the user wants in the cloud (unchanged during an upgrade)
2. Code - how the program expresses that intent using the provider API (may need updating)
3. Pulumi state - Pulumi's stored representation of what exists (may need reconciliation)
4. Real cloud - the actual infrastructure (should not change during an upgrade)