Gateway Example

Minimal demo of foomo/gateway routing — no Docker, no Kubernetes required.

Run

go run main.go

Everything runs in a single process:

Service	Role
Mock contentserver	Resolves URIs to mime types
Page frontend	Handles application/x-sandbox-page
News frontend	Handles application/x-sandbox-news
Error frontend	Handles 404 / 500 (errorFrontend: true)

Try it

# known page URI
curl -i http://localhost:8080/

# another page
curl -i http://localhost:8080/about

# news article (different mime type → different frontend)
curl -i http://localhost:8080/news/article-1

# unknown URI → routed to error frontend
curl -i http://localhost:8080/missing

# built-in gateway endpoints
curl -i http://localhost:8080/robots.txt
curl -i http://localhost:8080/sitemap.xml
curl -i http://localhost:8080/gateway/status

What to look for

• X-Content-Id and X-Mime-Type headers are set on the proxied request — the frontend reads them to fetch page payload and site context in parallel.
• X-Error-Code is set when routing to the error frontend.
• /sitemap.xml, /robots.txt, and /gateway/status are handled by the gateway itself.

Content tree

The mock contentserver (contentTree in main.go) defines the known URIs and their mime types. Edit it to try different routing scenarios.

In a real project the contentserver is a separate service loaded from your CMS. The gateway is unaware of mime type values — it routes whatever string the contentserver returns.