Cache content of Ajax Get call in varnish 5.2 - ajax

Question

I am new in varnish and using Varnish 5.2 and want to know why Varnish do not cache AJAX Get request while it does cache the content if same Ajax call is requested through a URL call from browser.
Following is the default.vcl file
vcl 4.0;
import std;
backend default {
.host = "127.0.0.1";
.port = "8080";
}
sub vcl_recv {
# Normalize the header, remove the port (in case you're testing this on various TCP ports)
set req.http.Host = regsub(req.http.Host, ":[0-9]+", "");
# Remove the proxy header (see https://httpoxy.org/#mitigate-varnish)
unset req.http.proxy;
# Normalize the query arguments
set req.url = std.querysort(req.url);
# Allow purging
if (req.method == "PURGE") {
# If you got this stage (and didn't error out above), purge the cached result
return (purge);
}
# Some generic cookie manipulation, useful for all templates that follow
# Remove the "has_js" cookie
set req.http.Cookie = regsuball(req.http.Cookie, "has_js=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "PHPSESSID=[^;]+(; )?", "");
# Remove any Google Analytics based cookies
set req.http.Cookie = regsuball(req.http.Cookie, "__utm.=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "_ga=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "_gat=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "utmctr=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "utmcmd.=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "utmccn.=[^;]+(; )?", "");
# Remove DoubleClick offensive cookies
set req.http.Cookie = regsuball(req.http.Cookie, "__gads=[^;]+(; )?", "");
# Remove the Quant Capital cookies (added by some plugin, all __qca)
set req.http.Cookie = regsuball(req.http.Cookie, "__qc.=[^;]+(; )?", "");
# Remove the AddThis cookies
set req.http.Cookie = regsuball(req.http.Cookie, "__atuv.=[^;]+(; )?", "");
set req.http.Cookie = regsuball(req.http.Cookie, "^;\s*", "");
if (req.http.cookie ~ "^\s*$") {
unset req.http.cookie;
}
if (req.url ~ "^[^?]*\.(7z|avi|bz2|flac|flv|gz|mka|mkv|mov|mp3|mp4|mpeg|mpg|ogg|ogm|opus|rar|tar|tgz|tbz|txz|wav|webm|xz|zip)(\?.*)?$") {
unset req.http.Cookie;
return (hash);
}
if (req.url ~ "^[^?]*\.(7z|avi|bmp|bz2|css|csv|doc|docx|eot|flac|flv|gif|gz|ico|jpeg|jpg|js|less|mka|mkv|mov|mp3|mp4|mpeg|mpg|odt|otf|ogg|ogm|opus|pdf|png|ppt|pptx|rar|rtf|svg|svgz|swf|tar|tbz|tgz|ttf|txt|txz|wav|webm|webp|woff|woff2|xls|xlsx|xml|xz|zip)(\?.*)?$") {
unset req.http.Cookie;
return (hash);
}
if (req.http.X-Requested-With == "XMLHttpRequest"){
return (hash);
}
set req.http.Surrogate-Capability = "abc=ESI/1.0";
return (hash);
}
sub vcl_backend_response {
set beresp.grace = 1200s;
set beresp.ttl = 120s;
if (beresp.http.Surrogate-Control ~ "ESI/1.0")
{ unset beresp.http.Surrogate-Control; // for Varnish >= 3.0 set beresp.do_esi = true; // for Varnish < 3.0 // esi;
}
}
Following is the response of varnishlog command file
* << Request >> 98313
- Begin req 98311 rxreq
- Timestamp Start: 1523473475.288141 0.000000 0.000000
- Timestamp Req: 1523473475.288141 0.000000 0.000000
- ReqStart 192.168.33.1 39288
- ReqMethod GET
- ReqURL /get-test/sf1102505aabc133ddbae?customerId=110250
- ReqProtocol HTTP/1.1
- ReqHeader Host: test-website.test
- ReqHeader Connection: keep-alive
- ReqHeader Pragma: no-cache
- ReqHeader Cache-Control: no-cache
- ReqHeader Accept: */*
- ReqHeader X-Requested-With: XMLHttpRequest
- ReqHeader User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36
- ReqHeader Referer: http://test-website.test/get-widget-110250-ProductID1
- ReqHeader Accept-Encoding: gzip, deflate
- ReqHeader Accept-Language: en,es;q=0.9,en-US;q=0.8
- ReqHeader Cookie: PHPSESSID=e41a91kihnchjn9c4aor07jl3p
- ReqHeader X-Forwarded-For: 192.168.33.1
- VCL_call RECV
- ReqUnset Host: test-website.test
- ReqHeader Host: test-website.test
- ReqURL /get-test/sf1102505aabc133ddbae?customerId=110250
- ReqUnset Cookie: PHPSESSID=e41a91kihnchjn9c4aor07jl3p
- ReqHeader Cookie: PHPSESSID=e41a91kihnchjn9c4aor07jl3p
- ReqUnset Cookie: PHPSESSID=e41a91kihnchjn9c4aor07jl3p
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- ReqHeader Cookie:
- ReqUnset Cookie:
- VCL_return hash
- ReqUnset Accept-Encoding: gzip, deflate
- ReqHeader Accept-Encoding: gzip
- VCL_call HASH
- VCL_return lookup
- VCL_call MISS
- VCL_return fetch
- Link bereq 98314 fetch
- Timestamp Fetch: 1523473475.452031 0.163890 0.163890
- RespProtocol HTTP/1.1
- RespStatus 200
- RespReason OK
- RespHeader Date: Wed, 11 Apr 2018 19:04:35 GMT
- RespHeader Server: Apache/2.4.7 (Ubuntu)
- RespHeader Access-Control-Allow-Origin: *
- RespHeader Access-Control-Allow-Credentials: true
- RespHeader Cache-Control: max-age=300, public
- RespHeader X-Cache-Debug: 1
- RespHeader Pragma: cache
- RespHeader X-Debug-Token: 4dda3e
- RespHeader X-Debug-Token-Link: http://test-website.test/_profiler/4dda3e
- RespHeader Vary: Accept-Encoding
- RespHeader Content-Encoding: gzip
- RespHeader Content-Length: 2039
- RespHeader Content-Type: text/css; charset=UTF-8
- RespHeader X-Varnish: 98313
- RespHeader Age: 0
- RespHeader Via: 1.1 varnish (Varnish/5.2)
- VCL_call DELIVER
- VCL_return deliver
- Timestamp Process: 1523473475.452071 0.163930 0.000039
- RespHeader Accept-Ranges: bytes
- RespHeader Connection: keep-alive
- Timestamp Resp: 1523473475.452225 0.164084 0.000155
- ReqAcct 589 0 589 527 2039 2566
- End
Remember: It gets a HIT if call directly from browser

Answer 1

do you have a varnishlog of the normal GET request - aka from the browser
i suspect that the xmlhttprequest - sends:
- ReqHeader Pragma: no-cache
- ReqHeader Cache-Control: no-cache
you either remove the 2 headers in vcl_recv by unsetting them:
sub vcl_recv {
unset req.http.Pragma;
unset req.http.Cache-Control;
}
or you disable it in the application itself. for example if you are using jquery
$.ajaxSetup({
cache: true
});
but depends on how you do the ajax requests.