Accessing resources on Caddy server causes VM to die

[DanKuehling]

Hi. I’m trying to set up what I thought was a pretty simple web server using Caddy on Ubuntu 18.04 but I’m running into a very strange problem. The intent of the server is as a software repo for the Munki software management tool for Macs, as well as running the Munkireport-PHP app for reporting info about the clients.

If I access the hosted files/pages from a Mac using Safari or from any command line tools on a Mac (curl or the Python-based Munki tools), the Ubuntu VM running Caddy locks up dead. It ceases to respond on the network at all and the console also stops responding. The only recourse I have is to reboot the VM from VMware. If I access the same resources from other browsers (Chrome, Firefox, IE 11, Edge), the VM stays up and content is served as expected.

My Caddyfile (anonymized):

munki.mydomain.org/munki_repo {
    root /usr/local/munki_repo
    tls email@mydomain.org
	basicauth / username password
}
munki.mydomain.org/munkireport {
	root /usr/local/munkireport/public
	tls email@mydomain.org
	# PHP-FPM Configuration for Caddy
     fastcgi / /run/php/php7.2-fpm.sock php {
         ext .php
         split .php
         index index.php
     }	
}

I suspected the PHP setup at first, but this happens even with the entire /munkireport site not running (commented out).

Thank you for any help you can provide. I haven’t been in the Linux game for a while (our server environment here is basically 100% Windows) so I apologize in advance for my lack of knowledge.

[Whitestrake (Matthew Fay)]

Wow, that’s certainly an impressive result from a simple HTTP connection from a Mac. Can’t say I’ve ever seen that kind of behaviour, personally. A few questions:

Which Caddy version are you running?

Does this error occur with a very simple Caddyfile, e.g:

http://
status 200 /

Does it go down only when provoked by one Mac in particular, or have you tested with multiple Macs?

Does curl from another Linux distro have the same effect? How about a Powershell Invoke-WebRequest?

If you take down Caddy and run Apache serving a simple page on the same ports, does that change the outcome?