Issue

Got connection timed out when trying to get the gpg key. For example,

gpg --keyserver keyserver.ubuntu.com --recv-keys 04EE7237B7D453EC

Solution

This is usually caused by your firewall blocking the port 11371. You could unblock the port in your firewall. In case you don't have access to the firewall, you could force gpg to use port 80 instead of 11371. For example,

gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 04EE7237B7D453EC 648ACFD622F3D138