fix(docker): use next-runtime instead of accessing next_public vars directly (#746)

Author: waleedlatif1

apps/sim/lib/env.ts

@@ -1,6 +1,17 @@
 import { createEnv } from '@t3-oss/env-nextjs'
+import { env as runtimeEnv } from 'next-runtime-env'
 import { z } from 'zod'
 
+/**
+ * Universal environment variable getter that works in both client and server contexts.
+ * - Client-side: Uses next-runtime-env for runtime injection (supports Docker runtime vars)
+ * - Server-side: Falls back to process.env when runtimeEnv returns undefined
+ * - Provides seamless Docker runtime variable support for NEXT_PUBLIC_ vars
+ */
+const getEnv = (variable: string): string | undefined => {
+  return runtimeEnv(variable) ?? process.env[variable]
+}
+
 export const env = createEnv({
   skipValidation: true,
 
@@ -131,18 +142,20 @@ export const env = createEnv({
   },
 
   experimental__runtimeEnv: {
-    NEXT_PUBLIC_APP_URL: process.env.NEXT_PUBLIC_APP_URL,
-    NEXT_PUBLIC_VERCEL_URL: process.env.VERCEL_URL,
-    NEXT_PUBLIC_SENTRY_DSN: process.env.NEXT_PUBLIC_SENTRY_DSN,
-    NEXT_PUBLIC_GOOGLE_CLIENT_ID: process.env.NEXT_PUBLIC_GOOGLE_CLIENT_ID,
-    NEXT_PUBLIC_GOOGLE_API_KEY: process.env.NEXT_PUBLIC_GOOGLE_API_KEY,
-    NEXT_PUBLIC_GOOGLE_PROJECT_NUMBER: process.env.NEXT_PUBLIC_GOOGLE_PROJECT_NUMBER,
-    NEXT_PUBLIC_SOCKET_URL: process.env.NEXT_PUBLIC_SOCKET_URL,
-    NODE_ENV: process.env.NODE_ENV,
-    NEXT_TELEMETRY_DISABLED: process.env.NEXT_TELEMETRY_DISABLED,
+    NEXT_PUBLIC_APP_URL: getEnv('NEXT_PUBLIC_APP_URL'),
+    NEXT_PUBLIC_VERCEL_URL: process.env.VERCEL_URL, // Keep as-is (server-only)
+    NEXT_PUBLIC_SENTRY_DSN: getEnv('NEXT_PUBLIC_SENTRY_DSN'),
+    NEXT_PUBLIC_GOOGLE_CLIENT_ID: getEnv('NEXT_PUBLIC_GOOGLE_CLIENT_ID'),
+    NEXT_PUBLIC_GOOGLE_API_KEY: getEnv('NEXT_PUBLIC_GOOGLE_API_KEY'),
+    NEXT_PUBLIC_GOOGLE_PROJECT_NUMBER: getEnv('NEXT_PUBLIC_GOOGLE_PROJECT_NUMBER'),
+    NEXT_PUBLIC_SOCKET_URL: getEnv('NEXT_PUBLIC_SOCKET_URL'),
+    NODE_ENV: process.env.NODE_ENV, // Keep as-is (build-time)
+    NEXT_TELEMETRY_DISABLED: process.env.NEXT_TELEMETRY_DISABLED, // Keep as-is (build-time)
   },
 })
 
 // Needing this utility because t3-env is returning string for boolean values.
 export const isTruthy = (value: string | boolean | number | undefined) =>
   typeof value === 'string' ? value === 'true' || value === '1' : Boolean(value)
+
+export { getEnv }