backend images_gluster1 {
        .host = "192.168.0.50";
        .port = "82";
        .connect_timeout = 15s;
        .first_byte_timeout = 60s;
        .between_bytes_timeout = 15s;
        # Backend polling: http://varnish.projects.linpro.no/wiki/BackendPolling
        .probe = {
                .url = "/polling/tour_search.png";
                .timeout = 10s;
                .interval = 1m;
                .window = 3;
                .threshold = 1;
        }
}

backend resources_gluster1 {
        .host = "192.168.0.50";
        .port = "83";
        .connect_timeout = 15s;
        .first_byte_timeout = 60s;
        .between_bytes_timeout = 15s;
        # Backend polling: http://varnish.projects.linpro.no/wiki/BackendPolling
        .probe = {
                .url = "/polling/tour_search.png";
                .timeout = 10s;
                .interval = 1m;
                .window = 3;
                .threshold = 1;
        }
}

sub vcl_init {
    # define directors and add backends
    # resources
    new res = directors.round_robin();
    res.add_backend(resources_gluster1);
    res.add_backend(resources_gluster2);
    res.add_backend(resources_gluster3);

    # images
    new img = directors.round_robin();
    img.add_backend(images_gluster1);
    img.add_backend(images_gluster2);
    img.add_backend(images_gluster3);

}

sub vcl_hash {
    hash_data(req.url);
    hash_data(req.http.host);
    if (req.url ~ "^/api/" && req.http.Accept ~ "json" ) {
        hash_data(req.http.Accept);
    }
    return(lookup);
}

sub vcl_hit {
    # Called when a cache lookup is successful.
    if (obj.ttl >= 0s) {
        # A pure unadultered hit, deliver it
        return (deliver);
    }

    if (std.healthy(req.backend_hint)) {
        # Backend is healthy. Limit age to 30s.
        if (obj.ttl + 30s > 0s) {
            #set req.http.grace = "normal(limited)";
            return (deliver);
        } else {
            # No candidate for grace. Fetch a fresh object.
            return(miss);
        }
    } else {
        # backend is sick - use full grace
        if (obj.ttl + obj.grace > 0s) {
            #set req.http.grace = "full";
            return (deliver);
        } else {
            # no graced object.
            return (miss);
        }
    }

    # fetch & deliver once we get the result
    return (miss); # Dead code, keep as a safeguard
}

sub vcl_miss {
    # Called after a cache lookup if the requested document was not found in the cache. Its purpose
    # is to decide whether or not to attempt to retrieve the document from the backend, and which
    # backend to use.

    return (fetch);
}

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.

    # Set server header
#    set req.grace = 3h;
    unset beresp.http.Server;
    set beresp.http.Server = "Apache/2 (CBM-64)";

    # Remove E-Tags from all replies except from json
    if (! (bereq.url ~ "\.json" || bereq.url ~ "\.jsonp")) {
        unset beresp.http.Etag;
    }

    # Don't cache 404 responses
    if (beresp.status == 404) {
	set beresp.ttl = 10s;
        set beresp.uncacheable = true;
        return (deliver);
    }
    else if (beresp.status<300) {
        set beresp.http.X-Varnish-Comment = "Caching rule applied";
        if (bereq.url ~ "^/img/" || bereq.url ~ "^/img2/" ) {
            unset bereq.http.Cookie;
            unset beresp.http.Set-Cookie;
            set beresp.ttl = 31d;
            set beresp.http.Cache-Control = "max-age=2678400";
            return(deliver);
        }
        # If no cookie set: Use default caching time
        if (!bereq.http.Cookie) {
            set beresp.ttl = 15m;
            set beresp.http.Cache-Control = "max-age=900";
            return(deliver);
        } else {
            set beresp.http.X-Varnish-Comment = "Logged in";
            set beresp.uncacheable = true;
            return(deliver);
        }
    } else {
        # Use very short caching time for error messages - giving the system the chance to recover
        set beresp.ttl = 120s;
        unset beresp.http.Cache-Control;
        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.
    if (obj.hits > 0) {
        set resp.http.X-Cache = "HIT";
    } else {
        set resp.http.X-Cache = "MISS";
    }

    set resp.http.X-Cache-Hits = obj.hits;

    return(deliver);
}