Add compression to some endpoints.

Consideration will be given to adding (conditional) compression
to all endpoints.

lib/www/server/api/middleware/compress/index.js

@@ -0,0 +1,16 @@
+const compression = require('compression');
+
+const compress = compression({
+	level: 6, // Balance speed vs. ratio (1-9)
+	threshold: 512, // Compress only if response >512 bytes to avoid overhead on small bundles
+	filter: (req, res) => { // Ensure bundles are compressed
+		if (req.get("Accept") == "application/vnd.aaltronav.dougal+octet-stream") {
+			return true;
+		}
+
+		// fallback to standard filter function
+		return compression.filter(req, res)
+	}
+});
+
+module.exports = compress;