Debug varnish cache

main.vcl

vcl 4.0;
import directors;
import var;
import std;

backend main {
    .host = "${VARNISH_BACKEND_HOST}";
    .port = "${VARNISH_BACKEND_PORT}";
    .first_byte_timeout = ${VARNISH_BACKEND_TIMEOUT};
}

sub vcl_init {
}

sub vcl_recv {
    if (req.method == "BAN") {
        ban("req.url ~ ."); // ban everything
        return(synth(200, "Ban added"));
    }

    var.set_real("req_start", std.time2real(now, 0));
    unset req.http.x-cache;
    set req.http.x-cache-path = "none";
    set req.backend_hint = main;

   # these are not handled
   if (req.method != "GET" &&
       req.method != "HEAD" &&
       req.method != "PUT" &&
       req.method != "POST" &&
       req.method != "OPTIONS" &&
       req.method != "DELETE") {
        return (synth(405)); /* not implemented */
    }

    # work only with GET or HEAD
    #
    # all other should be passed to the backend servers
    #
     if (req.method != "GET" && req.method != "HEAD") {
        set req.http.x-cache-path = "pass";
        return (pass);
    }

    # cache getRecordCover calls
    if (
        req.url ~ "^/AJAX/JSON\?method=getRecordCover" ||
        req.url ~ "^/AJAX/JSON\?method=getObalkyKnihWithoutSolr" ||
        #req.url ~ "^/AJAX/JSON\?.*&method=getACSuggestions" ||
        # req.url ~ "^/AJAX/JSON\?.*&method=getSideFacets" ||
        req.url ~ "^/themes" ||
        req.url ~ "^/robots.txt"
    ) {
        set req.http.x-cache-path = "hash-cacheable";
        return (hash);
   }

    set req.http.x-cache-path = "default-pass";
    return (pass);
}

sub vcl_hit {
       var.set_string("Cache-Action", "hit");

}

sub vcl_miss {
        var.set_string("Cache-Action", "miss");
}

sub vcl_pass {
        var.set_string("Cache-Action", "pass");
}

sub vcl_pipe {
        var.set_string("Cache-Action", "pipe");
}

sub vcl_synth {
        var.set_string("Cache-Action", "synth");
}


sub vcl_backend_fetch {
    var.set_real("bereq_start", std.time2real(now, 0));
}

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.

    var.set_real("generated_time", std.time2real(now, 1) - var.get_real("bereq_start"));
    set beresp.http.X-Backend-Time = var.get_real("generated_time");

  if (beresp.status == 404) {
        unset beresp.http.Expires;
        set beresp.http.Cache-Control = "public, max-age=900";
        unset beresp.http.Set-Cookie;
        set beresp.ttl = 60s;
        set beresp.grace = 30s;
        return (deliver);
  }

  if (beresp.status != 200) {
      set beresp.uncacheable = true;
      return (deliver);
  }

  if (
        bereq.url ~ "^/AJAX/JSON\?method=getRecordCover" ||
        bereq.url ~ "^/AJAX/JSON\?method=getObalkyKnihWithoutSolr" ||
        #bereq.url ~ "^/AJAX/JSON\?.*&method=getACSuggestions" ||
        #bereq.url ~ "^/AJAX/JSON\?.*&method=getSideFacets" ||
        bereq.url ~ "^/themes" ||
        bereq.url ~ "^/robots.txt"
   ) {
        unset beresp.http.Cache-Control;
        unset beresp.http.Pragma;
        unset beresp.http.Expires;
        unset beresp.http.Set-Cookie;
        set beresp.http.Cache-Control = "public, max-age=900";
        set beresp.ttl = 3600s;
        set beresp.grace = 90s;
        return (deliver);
  }

  set beresp.uncacheable = true;
  return (deliver);
}



sub vcl_deliver {
    var.set_real("processing_time", std.time2real(now, 1) - var.get_real("req_start"));
    set resp.http.X-Cache-Processing-Time = var.get_real("processing_time");

    if (obj.hits > 0) {
        set resp.http.X-Cache-Hit = "HIT, count=" + obj.hits;
    }

    // set resp.http.x-cache-path = req.http.x-cache-path;
    set resp.http.X-Cache-Action = var.get_string("Cache-Action");
    set resp.http.X-Dispatched-By = "${HOSTNAME}";
}