Add Let’s Encrypt SSL Certificate to Nagios 4.x running on CentOS 7

The easiest way to install Let’s Encrypt client by cloning github repository. To install git on your system you must enable Epel repositories with the following command

yum -y install epel-release

Install git client

yum -y install git

Change directory and go to /usr/src

cd /usr/src/

Clone Let’s Encrypt Client from Github

git clone 
cd /usr/src/letsencrypt

Run letsencrypt-auto script with your domain name

./letsencrypt-auto --apache -d FullyQualifiedDomainName

This Script will download and install all necessary packages.

Answer following questions.

- Enter email address ( Used for urgent renewal and security notices)
- Please read the Terms of Service and Accept it
- Would you be willing to share your email.....
- Select ssl.conf

IMPORTANT NOTES: – Congratulations! Your certificate and chain have been saved at:   /etc/letsencrypt/live/ YourFullDomainName/fullchain.pem   Your key file has been saved at:   /etc/letsencrypt/live/YourFullDomainName /privkey.pem   Your cert will expire on 2017-11-12. To obtain a new or tweaked   version of this certificate in the future, simply run   letsencrypt-auto again with the “certonly” option. To   non-interactively renew *all* of your certificates, run   “letsencrypt-auto renew” – Your account credentials have been saved in your Certbot   configuration directory at /etc/letsencrypt. You should make a   secure backup of this folder now. This configuration directory will   also contain certificates and private keys obtained by Certbot so   making regular backups of this folder is ideal.

Certificate has been installed successfully.

Let’s Encrypt certificate is only valid for 90 days. To renew automatically add following line to your corn job.

0 1 12 * * /usr/src/letsencrypt/certbot-auto renew