Hello,

The private network is not available during build -

https://docs.railway.app/guides/private-networking#caveats

Please run the migrations during runtime before starting your application.

As long as you use a readiness type health check Railway wont switch over traffic until your application is ready to handle traffic.

Brody, thank you!

I'll adjust accordingly

Hi Brody,

Thanks again for the clarification regarding the unavailability of the private network during the build phase. I understand that I need to run the migrations during runtime before starting the application.

However, I have a follow-up question: how can I conditionally use different database URLs during build time and runtime? For instance, during the build phase, when the internal database is unavailable, I want to use the DATABASE_PUBLIC_URL (to leverage Next.js' static route optimization). Here’s a code snippet that illustrates what I have in mind:

```

db: postgresAdapter({

pool: {

connectionString: process.env.IS_BUILD === 'true'

? env.DATABASE_PUBLIC_URL

: env.DATABASE_URL,

}

}),

```

This setup would allow the build process to use the public URL, avoiding the need for export const dynamic = 'force-dynamic'; in my Next.js page.tsx files. Once the application is deployed, it would switch to using DATABASE_URL to prevent egress fees and utilize Next.js' revalidation mechanisms for caching generated HTML.

Could you advise on whether this approach is feasible on Railway and, if so, any best practices for managing this conditional logic in the environment variables?

Thanks for your help!

Hey @brianfryer! Not Brody, but they can add some additional info when they see your message..

To answer the main question, it is totally acceptable to use the public URL during build and the internal URL at deployment, and some of our customers already do this. In the future, private network will be available at build time as well so you'll not have to manage this condition forever.

I think your ternary operator would do great!

In your package.json you can prefix your build script with IS_BUILD=true so that your code uses the correct URL with that ternary operator.

@melissa — awesome! thank you for letting me know!

@body — and thank you for chiming in as well.

Unfortunately, I'm getting an error when attempting to implement such logic.

In my environment, I have these variables set:

DATABASE_URL="${{Postgres.DATABASE_URL}}"
DATABASE_PUBLIC_URL="${{Postgres.DATABASE_PUBLIC_URL}}"

Here is my railway.json config file:

{
  "build": {
    "buildCommand": "IS_BUILD=true pnpm install --frozen-lockfile && pnpm run build || pnpm run payload migrate:down",
    "startCommand": "sleep 3 && pnpm run start"
  },
  "variables": {
    "NIXPACKS_NODE_VERSION": "18"
  }
}

And here is the relevant part of the logs:

#12 57.66 [23:05:40] ERROR: Error: cannot connect to Postgres. Details: getaddrinfo ENOTFOUND postgres.railway.internal
#12 57.66     err: {
#12 57.66       "type": "Error",
#12 57.66       "message": "getaddrinfo ENOTFOUND postgres.railway.internal",
#12 57.66       "stack":
#12 57.66           Error: getaddrinfo ENOTFOUND postgres.railway.internal
#12 57.66               at /app/node_modules/.pnpm/pg-pool@3.7.0_pg@8.11.3/node_modules/pg-pool/index.js:45:11
#12 57.66               at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
#12 57.66               at connectWithReconnect (/app/node_modules/.pnpm/@payloadcms+db-postgres@3.0.0-beta.116_payload@3.0.0-beta.116_graphql@16.9.0_monaco-editor@0._abenlmjs4wylc4gdw7q644nbea/node_modules/@payloadcms/db-postgres/src/connect.ts:22:14)
#12 57.66               at Object.connect (/app/node_modules/.pnpm/@payloadcms+db-postgres@3.0.0-beta.116_payload@3.0.0-beta.116_graphql@16.9.0_monaco-editor@0._abenlmjs4wylc4gdw7q644nbea/node_modules/@payloadcms/db-postgres/src/connect.ts:65:7)
#12 57.66               at BasePayload.init (/app/node_modules/.pnpm/payload@3.0.0-beta.116_graphql@16.9.0_monaco-editor@0.52.0_react-dom@19.0.0-rc-3edc000d-20240_evsx4covwley5xhuggvt42bcri/node_modules/payload/src/index.ts:518:7)
#12 57.66               at migrate (/app/node_modules/.pnpm/payload@3.0.0-beta.116_graphql@16.9.0_monaco-editor@0.52.0_react-dom@19.0.0-rc-3edc000d-20240_evsx4covwley5xhuggvt42bcri/node_modules/payload/src/bin/migrate.ts:45:3)
#12 57.66               at async start (file:///app/node_modules/.pnpm/payload@3.0.0-beta.116_graphql@16.9.0_monaco-editor@0.52.0_react-dom@19.0.0-rc-3edc000d-20240_evsx4covwley5xhuggvt42bcri/node_modules/payload/bin.js:30:7)
#12 57.66       "errno": -3008,
#12 57.66       "code": "ENOTFOUND",
#12 57.66       "syscall": "getaddrinfo",
#12 57.66       "hostname": "postgres.railway.internal"
#12 57.66     }

As you can see here, the build is failing because it couldn't connect to postgres.railway.internal (the non-public database URL) even though IS_BUILD=true is set in the buildCommand setting.

Any ideas on what I might be doing wrong?

Please don't run install commands in the build command, it's redundant as pnpm i --frozen-lockfile is already being ran in the install phase.

Try moving IS_BUILD=true into the build script in your package.json.

Aha! Thank you @brody, that did the trick.

Wow, this is awesome.

Awesome, glad you got it working!

Awesome, glad you got it working!

Similar issue but I have a remix app with the following vite.config.ts
where i inline environment variables at build time. is there any workaround?

export default defineConfig({
  define: {
    "process.env.API_URL": JSON.stringify(process.env.API_URL),
    "process.env.WS_API_URL": JSON.stringify(process.env.WS_API_URL),
  },
});

For Vite don't the variables need to be prefixed with VITE_ ?

For Vite don't the variables need to be prefixed with VITE_ ?

Wow that must be new

That's what their docs say -

https://vite.dev/guide/env-and-mode