How to SSL Cert Check using open source.

Any Linux flavour would work well. I recommend you start with Ubuntu. Download a Desktop edition and it has the UI.

Thanks but do you know how to implement it and eventually create a cron job to spit the SSL Certs that are going to expire ? Thanks

You can setup something like Nagios (https://www.nagios.org/projects/nagios-core) to automate the monitoring etc...What do you mean by implement? You can simply put it on a cron and run it as such, this is just a bash script.

That is my problem "simply do this on Linux"

You can install it into a VMware Workstation or Virtual Box.

Or if you have Windows 10OS you use something like this:
https://msdn.microsoft.com/en-us/commandline/wsl/about

How do you wish to proceed?

Plus one from me on OVH.

Hah! Recently I took on a new hosting client + dropped their monthly hardware bill from $2K/month to $200/month with massively faster hardware. I should be on the OVH payroll as must as I pump their biz. :)

I do have windows 7 though.

You can use Virtual Box or VMware Workstation in that case to install a virtual machine with Ubuntu on it.

When you setup an SSL cert, this relates to a public site on a public IP, resolvable via DNS.

You're saying you have some machine deployed at a hosting company running Windows 7, which you're using to host your site?

The problem is that SolarWinds does not have an alert for SSL Certs that are going to expire. It does monitor them though. So, I was googling and found the ssl-check open source.

Not sure which SolarWinds you have but there is an out of box function for this:
https://www.solarwinds.com/topics/ssl-certificate-monitor

Or for older versions:
https://support.solarwinds.com/Success_Center/Server_Application_Monitor_(SAM)/Monitor_SSL_certificate_expiration_date

Yes it does monitor but does not have alerting.