We are going to setup new certificate from Let’s Encrypt and use Apache as web server. We need to install the following packages beforehand. Server OS is Ubuntu 18.04.
ss is an useful Linux command line untility to get detailed information about TCP, UDP sockets and packets. It can display more information compare to
netstat according to man page.
Apache may sometime crash or stop for some other reasons. I had this issue with one of the server where Let’s Encrypt post hook does start Apache for whatever reasons.
GitLab(9.5) recently introduced GPG commit verification. On Ubuntu 16.04.x gpg2 is installed and can be used instead of gpg which is in the latest docs published for GPG with 9.5 release.