Let’s Encrypt on Centos 7

Install required packages

# sudo yum install epel-release
# sudo yum install httpd mod_ssl python-certbot-apache

Request an SSL Certificate

# sudo certbot --apache -d andeby.dk -d www.andeby.dk

Setup renewal cron

# sudo contab -e

Add the following

30 1 * * 1 /usr/bin/certbot renew >> /var/log/letsencrypt-renew.log

Check your certificate:
https://www.ssllabs.com/ssltest/analyze.html?d=morten.io&latest

Factor Exponent Prefix

---------------------------------------------------
1 000 000 000 000 000 000 000 000...10^24....yotta
1 000 000 000 000 000 000 000...10^21....zetta
1 000 000 000 000 000 000...10^18....exa
1 000 000 000 000 000...10^15....peta
1 000 000 000 000...10^12....tera
1 000 000 000...10^9.....giga
1 000 000...10^6.....mega
1 000...10^3.....kilo
100...10^2.....hecto
10...10^1.....deka
0.1...10^-1....deci
0.01...10^-2....centi
0.001...10^-3....milli
0.000 001...10^-6....micro
0.000 000 001...10^-9....nano
0.000 000 000 001...10^-12...pico
0.000 000 000 000 001...10^-15...femto
0.000 000 000 000 000 001...10^-18...atto
0.000 000 000 000 000 000 001...10^-21...zepto
0.000 000 000 000 000 000 000 001...10^-24...yocto
---------------------------------------------------

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