Let’s Encrypt has finally announced support for free wildcard subdomain certificate applications in the community. This is a blessing for individuals who need multiple subdomain certificates, because Let’s Encrypt is a CA authority, but this CA authority is free! This means that issuing certificates doesn’t require any fees.

Most companies today customize the original features or rules of frameworks to some extent when using them, making them more suitable for the company’s actual development scenarios.

I’ve been using username and password to log in to Linux servers, but recently I found many failed login attempts in the Linux logs, with many IPs trying to brute force user passwords. For security reasons, I decided to disable password login and use SSH RSA Key for authentication instead.