http://nginx.org/en/linux_packages.html#Debian

echo "deb http://nginx.org/packages/debian $(lsb_release -cs) nginx" | tee /etc/apt/sources.list.d/nginx.list
echo -e "Package: *\nPin: origin nginx.org\nPin: release o=nginx\nPin-Priority: 900\n" | tee /etc/apt/preferences.d/99nginx
curl -o /etc/apt/trusted.gpg.d/nginx_signing.asc https://nginx.org/keys/nginx_signing.key