We have a Forge app and we are trying to provide a data migration for our customers this is not technically possible. There is no way to implement your own solution for data migration. Because, migrating to cloud changes all the entity IDs for example issue id, worklog id. We have our own data associated with worklogs and issues through this ID and there is no way to get new IDs for entities. So, suggested workaround, " vendors can provide an app data migration path outside of the Cloud Migration Assistants " is not applicable.
Although Forge apps are not supported, I have updated our server app and implemented automated migration. My idea was, saving the mapping provided to onStartAppMigration method to a JSON file and import this JSON file to our Cloud app manually. But this was also not possible. Migration Assistant insist that our app is not installed to the cloud site, although it is. I think migration assistant needs your app to be a Connect App. Can you remove this check? If you remove this check, we can save mappings to a JSON file in onStartAppMigration method and perform a manual upload to our Forge app.
You are pushing all customers to the Cloud, suggesting vendors to use Forge platform and leaving us without any solution to port our customer data. I hope, I’m missing something here. If so, please suggest a workaround.