Add assetPrefix to next config (e2b-dev#569)

This pr adds `assetPrefix` property to the `next.config ` for production
builds. This makes sure that absolute urls instead of relative ones are
used on asset urls in the html markup, which makes it possible to proxy
this app from our upcoming new next app.

Author: jakubno

apps/web/next.config.mjs

@@ -31,7 +31,7 @@ function getFilesHash(rootPath) {
     shasum.update(delimiter)
   }
 
-  fsWalk.walkSync(rootPath, { stats: true }).forEach(e => {
+  fsWalk.walkSync(rootPath, { stats: true }).forEach((e) => {
     if (!e.stats.isDirectory()) {
       if (e.path.includes('/node_modules/')) return // ignore node_modules which may contain symlinks
       const content = fs.readFileSync(e.path, 'utf8')
@@ -48,17 +48,23 @@ const codeSnippetsDir = path.resolve('./src/code')
 const nextConfig = {
   pageExtensions: ['js', 'jsx', 'ts', 'tsx', 'mdx'],
   basePath: '',
+  assetPrefix:
+    process.env.NODE_ENV === 'production'
+      ? `https://${process.env.VERCEL_URL}`
+      : undefined,
   headers: async () => [
     {
       source: '/:path*',
-      headers: [{
-        // config to prevent the browser from rendering the page inside a frame or iframe and avoid clickjacking http://en.wikipedia.org/wiki/Clickjacking
-        key: 'X-Frame-Options',
-        value: 'SAMEORIGIN'
-      }],
-    }
+      headers: [
+        {
+          // config to prevent the browser from rendering the page inside a frame or iframe and avoid clickjacking http://en.wikipedia.org/wiki/Clickjacking
+          key: 'X-Frame-Options',
+          value: 'SAMEORIGIN',
+        },
+      ],
+    },
   ],
-  webpack: config => {
+  webpack: (config) => {
     const codeFilesHash = getFilesHash(codeSnippetsDir)
     config.cache.version = config.cache.version + delimiter + codeFilesHash
     return config
@@ -71,9 +77,9 @@ const nextConfig = {
           destination: 'https://app.posthog.com/:path*',
           // BEWARE: setting basePath will break the analytics proxy
         },
-      ]
+      ],
     }
-  }
+  },
 }
 
 export default withSearch(
@@ -91,7 +97,7 @@ export default withSearch(
         tunnelRoute: '/monitoring',
         hideSourceMaps: true,
         disableLogger: true,
-      },
-    ),
-  ),
+      }
+    )
+  )
 )