Migrate from Nhost v1 to v2

This is a guide that explains how to migrate a project from Nhost v1 to Nhost v2.

Upgrading from Nhost v1 to v2 requires database schema and Hasura metadata changes.

Upgrade Steps

Create a new Nhost v2 app locally

Make sure you have the Nhost CLI installed.

Update Config

Update version: 3 to version: 2 in nhost/config.yaml. This will update Hasura's configuration version, and we need to downgrade the version when we export migrations and metadata.

Export current migrations and metadata from Nhost v1

Inside the nhost/ folder of your app, run:

Update Migrations

Make the following changes manually to your migrations.

The migration file is located at nhost/migrations/[timestamp]/up.sql.

• Add OR REPLACE after CREATE for the public.set_current_timestamp_updated_at function
• Delete all auth.* tables and functions (if any).
• Delete public.users table and everything related to the table such as constraints, triggers, etc.
• Update FK references from public.users to auth.users (if any).

Update Metadata

Make the following changes manually to your metadata.

The metadata is located at nhost/metadata/tables.yaml.

• Delete tracking all tables in the auth schema.
• Delete tracking the public.users table.
• Update all references to users from the public to auth schema.

Start nhost

Start Nhost locally using the CLI. From the root of your app, run:

Running nhost -d applies your local database migrations and Hasura metadata.

Restart Auth and Storage Containers

Open Docker UI and restart Hasura Auth and Hasura Storage. Restarting those containers applies new metadata, effectively tracking everything in the auth and the storage schema.

Delete Migrations and Metadata

Delete the local migrations and metadata.

Update Config (again)

Update config: 2 to config: 3 in nhost/config.yaml.

Pull Migrations and Metadata from the Local Instance

In the nhost/ folder, run the following command:

Note: You cannot use port 1337 in the commands above. You have to use the specific port Hasura uses. Go to the Hasura Console under API and look for the port Hasura is using under GraphQL Endpoint.

Done

You now have a Nhost v2 project locally with correct migrations and metadata.

Transfer Data

To fully migrate, you need to transfer data from v1 to v2. This can be done in three steps:

1. Read data from v1
2. Modify data so it can be imported to v2
3. Write data to v2

You can also use TransferGraph, an open source tool from the community that helps you do this.