Prisma can't connect with an IPv6 host (on e.g. Fly.io)

[Fenntasy]

Bug description

In a DATABASE_URL, if the host is an IPv6, Prisma will throw an error, for instance, using this connection string

postgresql://postgres:postgres@[::1]:5432/db

will result in this error

Can't reach database server at `[::1]`:`5433`

I know that locally I could always use localhost or 127.0.0.1 but the bug is more of a problem if you're using a service like Fly that has started populating DATABASE_URL with IPv6 addresses. It just doesn't work out of the box.

psql and the pg node package don't have a problem with them so it's a problem with Prisma.

How to reproduce

Any local PG connection string looking like

postgresql://postgres:postgres@[::1]:5432/db

will create the error

Expected behavior

It should be able to connect.

Prisma information

The schema or queries are irrelevant here since it just doesn't connect.

Environment & setup

• OS: at least macOS and linux
• Database: PostgreSQL
• Node.js version: v18.12.1 (but it doesn't seem linked to that)

Prisma Version

prisma                  : 4.10.1
@prisma/client          : 4.10.1
Current platform        : darwin-arm64
Query Engine (Node-API) : libquery-engine aead147aa326ccb985dcfed5b065b4fdabd44b19 (at node_modules/@prisma/engines/libquery_engine-darwin-arm64.dylib.node)
Migration Engine        : migration-engine-cli aead147aa326ccb985dcfed5b065b4fdabd44b19 (at node_modules/@prisma/engines/migration-engine-darwin-arm64)
Format Wasm             : @prisma/prisma-fmt-wasm 4.10.1-1.80b351cc7c06d352abe81be19b8a89e9c6b7c110
Default Engines Hash    : aead147aa326ccb985dcfed5b065b4fdabd44b19
Studio                  : 0.481.0
Preview Features        : tracing

[cinder-star]

I would like to investigate on this issue

[cinder-star]

After going through the code, I found that the $connect() function uses prisma engine. The implementation is in https://github.com/prisma/prisma-engines

[DAlperin]

Hello from fly.io! As @Fenntasy noted, this bug has an unfortunate effect on prisma apps running on our platform. We'd love to see this fixed. Let me know if any additional information would be useful, or any other way we can help.

[maticzav]

@janpio is there any workaround for this that we could use?

[cinder-star]

@maticzav if you are facing this issue on fly.io, you can attach an ipv4 address to your database and use that. Read here

[maticzav]

@cinder-star sweet, thanks!

And how can I find user, password and dbname of a running database?

[cinder-star]

The dbname, user and password are the same as the connection string with the ipv6 one. You just need to replace the hostname with the ipv4 host. @maticzav

[maticzav]

@cinder-star I tried setting up the IPv4 url and manually changing the postgresql url, but that didn't play well with the Prisma Migrate. I did manage to get it working though.

1. I checked the credentials, which I also found out are only displayed once when you create the PG instance (so you can't use the "automatically" created instance),
2. I manually recreated the PG instance, connected to it from TablePlus and created a database (e.g. dbname).
3. I replaced the IPv6 address with myapp.internal (e.g. postgresql://postgres:password@myapp.internal:5432/dbname).

Some useful links and code chunks that helped me figure out

• https://fly.io/docs/postgres/connecting/app-connection-examples/#connecting-with-prisma-node-js
• https://fly.io/docs/postgres/connecting/connecting-external/

[build]
  dockerfile = "server/Dockerfile"

[deploy]
  release_command = "pnpm migrate:db"

{
  "scripts": {
    "migrate:db": "prisma migrate deploy --schema server/prisma/schema.prisma"
  }
}

Thanks again for helping me again 🙏 !

[cinder-star]

@maticzav i think you need to add sslmode to the url as well.
postgresql://postgres:password@myapp.internal:5432/dbname?sslmode=disabled
Something like that

[Fenntasy]

@maticzav i think you need to add sslmode to the url as well.
postgresql://postgres:password@myapp.internal:5432/dbname?sslmode=disabled
Something like that

It's not needed for the .internal URL.

But in any case, this issue shouldn't be about how to fix the problem with Fly when the problem lies with Prisma.

[VyrekXD]

Is there any fix to this problem?

[alula]

This affects everything that uses IPv6 addresses in URLs directly, not just fly.io, old title was fine