If you started an instance from the official CentOS AMI on AWS, you are running kernel 3.1 as of this writing, while you could easily take advantage of improved security features of newer kernels that are already available in a stable release. Renowned Linux kernel maintainer Greg Kroah-Hartman released the new Linux Kernel 4.14.15, which includes important fixes for Spectre & Meltdown. Here is how to update your Linux kernel from 3.1 to 4.14.15 in place.
The AWS Command Line Interface (CLI) is a set of tools AWS provides to allow you to administer your AWS cloud infrastructure and other services in the command line on Windows, Mac and Linux. Installing them is quick and easy. Here is a quick guide to get you started.
In order to figure out how many days your letsencrypt certificates have left, you could check an online services such as:
However, that won’t work for a mail server that’s not also running a web server using the same certificate.
In this case, your best bet is to check the certificate file directly using the openssl command as follows:
openssl x509 -noout -dates -in /etc/letsencrypt/live/smtp.yourmailserverdomainname.com/cert.pem
Your users want to access a web server instance as a staging or production environment for DevOps… They want access to the web server document root of the sites they manage. Your job is to maintain the integrity of the whole system in terms of cyber security.
If you happen to be running a web server on Linux—for example in EC2 on Amazon AWS—and need to provide site owners remote access in a secure and responsible manner, here is how to do it.
Logs that grow in size uncontrollably can cause unintended consequences. If you keep ignoring the situation, it will only get worse until you run our of disc space, the system starts being unresponsive or processes begin to crash.