Varnish Check

default.vcl

backend default {
    .host = "127.0.0.1";
    .port = "8080";
}

sub vcl_recv {
    if (req.http.host ~ "^cdn\.myapiservice\.com") {
        set req.http.host = "api.myapiservice.com";
        set req.url = regsub(req.url, "^/", "/v1/images/");
    }

    if (!req.backend.healthy||req.http.host ~ "^cdn\.myapiservice\.com"||req.url ~ "^.*v1/images/.*") {
        if (req.request == "GET" ||
#            req.request == "OPTIONS" ||
                req.request == "HEAD" 
           ) { 
            unset req.http.Authorization;
            unset req.http.Cookie;

            return (lookup);
        }
    }

}

sub vcl_deliver {
    if (obj.hits > 0) {
        set resp.http.X-Varnish-Cache = "HIT";
    }
    else {
        set resp.http.X-Varnish-Cache = "MISS";
    }

    return (deliver);
}

sub vcl_fetch {
#set beresp.ttl = 6s;

    if (beresp.ttl <= 0s) {
        set beresp.http.X-Cacheable = "NO:Not Cacheable";
        /*
         * Mark as "Hit-For-Pass" for the next 2 minutes
         */
        /** **/
        set beresp.http.X-Varnish-Api = "API";
        unset beresp.http.set-cookie;

        set beresp.ttl = 120 s;
        return (deliver);
        /** **/

        /**
        return (hit_for_pass);
        **/
 
    } elsif (req.http.Cookie ~ "(UserID|_session)") {
        set beresp.http.X-Cacheable = "NO:Got Session";
        return(hit_for_pass);
    } elsif (beresp.http.Cache-Control ~ "private") {
        set beresp.http.X-Cacheable = "NO:Cache-Control=private";
        return(hit_for_pass);
    }

    if (beresp.status >= 500 && beresp.status <= 599) {
        set beresp.http.X-Cacheable = "NO: 500";
        return(hit_for_pass);
    }

    if (beresp.status >= 400 && beresp.status <= 499) {
        set beresp.http.X-Cacheable = "NO: 400";
        set beresp.ttl = 0s;
        return (hit_for_pass);
    }

    if (req.http.host ~ "^cdn\.myapiservice\.com"||req.url ~ "^.*v1/images/.*") {
        set beresp.ttl = 730h;
        unset beresp.http.set-cookie;
        return (deliver);
    }

    return (deliver);
}

sub vcl_error {
    set obj.http.Content-Type = "application/json";
    synthetic {"{error: "} + obj.status + " " + obj.response + {"}"};
    return (deliver);
}

sub vcl_hit {
    if (req.request == "PURGE") {
        set obj.ttl = 0s;
        error 200 "Purged.";
    }

    return (deliver);
}

sub vcl_miss {
    if (req.request == "PURGE") {
        error 404 "Not in cache.";
    }

    return (fetch);
}