Lets Encrypt with Certbot on Raspbian Jessie

sudo nano /etc/apt/sources.list

deb http://ftp.debian.org/debian jessie-backports main

gpg --keyserver pgpkeys.mit.edu --recv-key 8B48AD6246925553
gpg -a --export 8B48AD6246925553 | sudo apt-key add -

gpg --keyserver pgpkeys.mit.edu --recv-key 7638D0442B90D010
gpg -a --export 7638D0442B90D010 | sudo apt-key add -

sudo a2enmod ssl

sudo apt-get update

sudo apt-get install python-certbot-apache -t jessie-backports -y

sudo certbot --apache certonly

When not working, this may work instead:
sudo certbot certonly --authenticator standalone --installer apache --pre-hook "systemctl stop apache2" --post-hook "systemctl start apache2"
#https://community.letsencrypt.org/t/solution-client-with-the-currently-selected-authenticator-does-not-support-any-combination-of-challenges-that-will-satisfy-the-ca/49983/15


#References
#https://letsencrypt.org/getting-started/
#https://certbot.eff.org/#debianjessie-apache
#https://backports.debian.org/Instructions/
#http://raspberrypi.stackexchange.com/questions/12258/where-is-the-archive-key-for-backports-debian-org

Unifi on Pi

sudo apt-get update
sudo apt-get -y upgrade

#Unifi

sudo sh -c 'echo "deb http://www.ubnt.com/downloads/unifi/debian stable ubiquiti" >> /etc/apt/sources.list'

sudo apt-get install -y dirmngr

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv C0A52C50

sudo apt-get update

sudo apt-get install -y unifi

#Configs:
/var/lib/unifi/
#https://help.ubnt.com/hc/en-us/articles/204952144-UniFi-How-can-I-restore-a-backup-configuration-

#Uninstall:
sudo apt-get remove --purge unifi

#http://www.lowefamily.com.au/2016/06/02/installing-ubiquiti-unifi-controller-5-on-raspberry-pi/
#https://help.ubnt.com/hc/en-us/articles/220066768-UniFi-Debian-Ubuntu-APT-howto
#https://help.ubnt.com/hc/en-us/articles/204952144-UniFi-How-can-I-restore-a-backup-configuration-

#Reset
https://help.ubnt.com/hc/en-us/articles/205143490-UniFi-How-to-reset-the-UniFi-Access-Point-to-factory-defaults