Although HAProxy is not a web server, it does have Small Object Caching so files can be cached on the proxy. https://www.haproxy.com/blog/whats-new-haproxy-1-8/#http-sma...

It can proxy and cache them.

There is a hacky way to serve single page static files directly via haproxy, by creating a http file (including headers) and add it to a custom back-end. This is really only useful if you have one or two pages you need to serve and don't want to run another web server. Some people use this for outage or maintenance pages.

    acl landing path_beg /demo
    use_backend landing if landing

    backend landing
        mode http
        fullconn        10000
        errorfile 503 /opt/ha/landing_page.http
        http-request    set-log-level silent


    # cat landing_page.http

    HTTP/1.1 200 Ok
    Cache-Control: no-cache, no-store
    Connection: close
    Content-Type: text/plain

    This is a static text file served directly from HAproxy 1.9

    I will catch grief for showing this.

Then use acl's to send specific requests to that page. Obviously change/add headers as required for the content in the file and use-case. Perhaps useful for outage or maintenance pages. Use your imagination for other use cases where you might want to automatically serve such a page.

Here it is in use: [1]

[1] - https://tinyvpn.org/demo