64 lines
1.8 KiB
JavaScript
64 lines
1.8 KiB
JavaScript
const express = require('express');
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const path = require('path');
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const app = express();
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const PORT = process.env.PORT || 80;
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const BACKEND_URL = process.env.BACKEND_URL;
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app.use(express.json());
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// Serve static React build
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app.use(express.static(path.join(__dirname, 'dist')));
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// Proxy endpoint - fetches identity token and forwards to backend
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app.post('/api/chat/stream', async (req, res) => {
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try {
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// Fetch identity token from GCP metadata server
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const tokenResponse = await fetch(
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`http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/identity?audience=${BACKEND_URL}`,
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{ headers: { 'Metadata-Flavor': 'Google' } }
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);
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const identityToken = await tokenResponse.text();
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// Forward request to backend with auth
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const backendResponse = await fetch(`${BACKEND_URL}/chat/stream`, {
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method: 'POST',
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headers: {
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'Content-Type': 'application/json',
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'Authorization': `Bearer ${identityToken}`,
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},
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body: JSON.stringify(req.body),
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});
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// Stream response back to client
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res.setHeader('Content-Type', 'text/event-stream');
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res.setHeader('Cache-Control', 'no-cache');
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res.setHeader('Connection', 'keep-alive');
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const reader = backendResponse.body.getReader();
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const pump = async () => {
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const { done, value } = await reader.read();
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if (done) {
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res.end();
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return;
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}
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res.write(value);
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pump();
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};
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pump();
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} catch (error) {
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console.error('Proxy error:', error);
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res.status(500).json({ error: 'Proxy error' });
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}
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});
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// SPA fallback - all other routes serve index.html
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app.get('/*', (req, res) => {
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res.sendFile(path.join(__dirname, 'dist', 'index.html'));
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});
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app.listen(PORT, () => {
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console.log(`Server running on port ${PORT}`);
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});
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