1 files changed, 65 insertions, 0 deletions
diff --git a/src/frontend/pages/_document.tsx b/src/frontend/pages/_document.tsx
new file mode 100644
index 0000000..8a68bc0
--- /dev/null
+++ b/src/frontend/pages/_document.tsx
@@ -0,0 +1,65 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+import Document, { DocumentContext, Html, Head, Main, NextScript } from 'next/document';
+import { ServerStyleSheet } from 'styled-components';
+import {context, propagation} from "@opentelemetry/api";
+
+const { ENV_PLATFORM, WEB_OTEL_SERVICE_NAME, PUBLIC_OTEL_EXPORTER_OTLP_TRACES_ENDPOINT, OTEL_COLLECTOR_HOST} = process.env;
+
+export default class MyDocument extends Document<{ envString: string }> {
+  static async getInitialProps(ctx: DocumentContext) {
+    const sheet = new ServerStyleSheet();
+    const originalRenderPage = ctx.renderPage;
+
+    try {
+      ctx.renderPage = () =>
+        originalRenderPage({
+          enhanceApp: App => props => sheet.collectStyles(<App {...props} />),
+        });
+
+      const initialProps = await Document.getInitialProps(ctx);
+      const baggage = propagation.getBaggage(context.active());
+      const isSyntheticRequest = baggage?.getEntry('synthetic_request')?.value === 'true';
+
+      const otlpTracesEndpoint = isSyntheticRequest
+          ? `http://${OTEL_COLLECTOR_HOST}:4318/v1/traces`
+          : PUBLIC_OTEL_EXPORTER_OTLP_TRACES_ENDPOINT;
+
+      const envString = `
+        window.ENV = {
+          NEXT_PUBLIC_PLATFORM: '${ENV_PLATFORM}',
+          NEXT_PUBLIC_OTEL_SERVICE_NAME: '${WEB_OTEL_SERVICE_NAME}',
+          NEXT_PUBLIC_OTEL_EXPORTER_OTLP_TRACES_ENDPOINT: '${otlpTracesEndpoint}',
+          IS_SYNTHETIC_REQUEST: '${isSyntheticRequest}',
+        };`;
+      return {
+        ...initialProps,
+        styles: [initialProps.styles, sheet.getStyleElement()],
+        envString,
+      };
+    } finally {
+      sheet.seal();
+    }
+  }
+
+  render() {
+    return (
+      <Html>
+        <Head>
+          <link rel="preconnect" href="https://fonts.googleapis.com" />
+          <link rel="preconnect" href="https://fonts.gstatic.com" crossOrigin="anonymous" />
+          <link
+            href="https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;1,300;1,400;1,500;1,600;1,700;1,800&display=swap"
+            rel="stylesheet"
+          />
+        </Head>
+        <body>
+          <Main />
+          <script dangerouslySetInnerHTML={{ __html: this.props.envString }}></script>
+          <NextScript />
+        </body>
+      </Html>
+    );
+  }
+}