Varnish 4.0 Simple Configuration

default.vcl

#
# This is an example VCL file for Varnish.
#
# It does not do anything by default, delegating control to the
# builtin VCL. The builtin VCL is called when there is no explicit
# return statement.
#
# See the VCL chapters in the Users Guide at https://www.varnish-cache.org/docs/
# and http://varnish-cache.org/trac/wiki/VCLExamples for more examples.

# Marker to tell the VCL compiler that this VCL has been adapted to the
# new 4.0 format.
vcl 4.0;

# Default backend definition. Set this to point to your content server.
backend default {
    .host = "localhost";
    .port = "8080";
}

sub vcl_recv {
    # Happens before we check if we have this in cache already.
    #
    # Typically you clean up the request here, removing cookies you don't need,
    # rewriting the request, etc.

    set req.backend_hint = default;

    unset req.http.Cookie;
        
    return(hash);
}

sub vcl_miss {
    
    # Just pass the request along to the subroutine which will fetch something from the backend.
    return(fetch);
}

sub vcl_hit {
    
    # Pass the request along to the subroutine which will deliver a result from the cache.
    return(deliver);
}

sub vcl_backend_response {
    # Happens after we have read the response headers from the backend.
    #
    # Here you clean the response headers, removing silly Set-Cookie headers
    # and other mistakes your backend does.
    # Get the response. Set the cache lifetime of the response to 1 hour.
    set beresp.ttl = 1h;

    # Indicate that this response is cacheable. This is important.
    set beresp.http.X-Cacheable = "YES";
    
    # Now pass this backend response along to the cache to be stored and served.
    return(deliver);
}

sub vcl_deliver {
    # Happens when we have all the pieces we need, and are about to send the
    # response to the client.
    #
    # You can do accounting or modifying the final object here.
    return(deliver);

}