I came across signature invalid error when trying to update Debian packages from packages.sury.org. It turned out to be a known expired key issue occurred recently. The following commands should fix it.
It's always nice to have a blog to capture what you've done over time. After researching around I eventually went with Google Cloud WordPress Click to Deploy for my blog website because Google offers $300 free trial and it is fairly easy to setup. I also need to secure my website with SSL/HTTPS so I went with Let's Encrypt as it is free. To make sure that I don't need to manually renew certificates (the virtue of being lazy 😉 ), I also set up a cron job to renew certificates automatically. Let's see how all these were set up!…