Install vSphere 4 client on Windows 10

I ran into a number of errors attempting to install an older vSphere client in Windows 10. The first error says "This product can only be installed on Windows XP SP2 and above".  This issue is described in this VMware KB article.  I fixed this by right-clicking the installer executable and selecting to run it in Windows XP SP3 compatibility mode.  After that the installer seemed to run but would ultimately silently fail without installing anything.  It turns out that the installer requires .NET 3.5 to be installed.  These instructions from Microsoft show how to install this prerequisite in Windows 10, and it did not require a reboot for me.  Once vSphere 4 was installed I was able to successfully run it as well as update to later version when connecting to vCenter servers on newer ESXi.

Spiceworks HTTPS Redirect Breaks Stuff

We recently moved our Spiceworks installation to HTTPS.  While there's a handy setting in the options to force user connections to the portal to use HTTPS, this doesn't affect the backend used by admin and helpdesk staff.  There's a lot of bad advice out there about how to accomplish this redirect. Many threads like this one suggest adding a 302 redirect to a port 80 virtualhost to redirect to https.  While this does appear to work initially you will find that incoming emails no longer generate tickets.   If you view the production.txt log in C:\Program Files(x86)\Spiceworks\log\ you'll see an entry like this:

I[08:12:09.44 9b1030] scheduled call to check for ticket email url_ping: /tickets/check_email (http://127.0.0.1:80/tickets/check_email)
W[08:12:09.44 9b1030] check for ticket email url_ping: /tickets/check_email => unexpected response: Net::HTTPMovedPermanently

Yep, that's right - Spiceworks uses an internal API on port 80.  What's worse is that it does not follow the 302 redirect correctly, so if you go this route it will not work.  Luckily there are a number of other threads like this one on the Spiceworks forum that have a better suggestion - using Apache mod_rewrite to accomplish the task.  Specifically you will need to add the following directives to the httpd.conf file in C:\Program Files(x86)\Spiceworks\httpd\conf:

RewriteEngine On
RewriteCond %{REMOTE_HOST} !^127\.0\.0\.1
RewriteCond %{HTTPS} !=on
RewriteRule ^/?(.*) https://%{SERVER_NAME}/$1 [R,L]

This will also require that you have the directive:

LoadModule rewrite_module modules/mod_rewrite.so

somewhere in the config but this appears to happen by default.  Essentially this will rewrite any HTTP requests to HTTPS with the exception of 127.0.0.1, the loopback addressed used by Spiceworks for internal API calls.