Generate CSR

Trick copyright: The Book of Secret Knowledge <https://github.com/trimstray/the-book-of-secret-knowledge>

( _fd="private.key" ; _fd_csr="request.csr" ; \
openssl req -out ${_fd_csr} -new -key ${_fd} )

click the source code to copy install openssl on any operating system with command-not-found.com