Hi everyone,
I just want to share my quick solution for checking HTTP sites (with perfdata) for proper HTTP/2 support and for sites that redirect with required cookies (e.g. PHPSESSID) using a Classical active and passive Monitoring check with the curl command line tool:
HTTP/2:
Command line:
/usr/bin/curl -s -o /dev/null -w 'HTTP/%{http_version} %{http_code} - %{size_download} bytes in %{time_total} second response time|time=%{time_total}s size=%{size_download}B time_connect=%{time_connect}s time_firstbyte=%{time_starttransfer}s\n' -k --http2-prior-knowledge --resolve $_HOSTFQDN$:443:$HOSTADDRESS$ https://$_HOSTFQDN$
(I have defined FQDN as a Custom Host Attribute so I can use this service definition as a template.)
HTTP/1.1 following redirects while keeping cookies:
Command line:
/usr/bin/curl -s -o /dev/null -w 'HTTP/%{http_version} %{http_code} - %{size_download} bytes in %{time_total} second response time|time=%{time_total}s size=%{size_download}B time_connect=%{time_connect}s time_firstbyte=%{time_starttransfer}s\n' -L -c- --http1.1 --resolve <FQDN>:443:$HOSTADDRESS$ https://<FQDN>
(The magic lies in the -c- switch).
Hope that helps someone with similar problems or maybe someone has an even more elegant solution 
Regards,
Moritz
PS: Old thread on that issue: [Check_mk (english)] Check_http cookie support