So,
I used to install puppet module via http://forge.puppetlabs.com without any issues. But then all of a sudden I am getting an error 301 Moved Permanently when trying to install any modules.
I would run the following command
puppet module install --module_repository http://forge.puppetlabs.com puppetlabs-dism
Now this appears to fail.
I have used both 3.4.2 and 3.8.7 (updated thinking their was an issue with the version)
I also have a similar command for ubuntu which works fine, but this is without the module_repository parameter.
The reason for the --module_repository flag is to get around the ssl certificate issue not being valid.
So the question being, has this functionality been removed, or does anyone know how to get the ssl certificate to be valid.
The url is in the process of being changed to https://forge.puppet.com as explained in ticket FORGE-327. Try using the updated url and see if that works for you.
As for the ssl error, see the documentation here and look at the first bullet point. It describes the reason this is happening and solutions for it.