Sad about manually updating your TXT-Records every 3 months?
Sad about complicated installations?
Let's start changing this!!!

Some words why doing it this way:

I installed letsencrypt on my webserver-vm but don't want to run a DNS server on the same machine. So i decided to split it up. Sure you can install bind also local or combined with letsencrypt on a single vm and so on.

1. Install new VM

• Debian (512MB to 1GB RAM / 1 CPU / 2GB Disk - 512MB Swap)
• Bind9 # apt-get install -y bind9
• make IP of VM static and notice

Configure Bind9:

/etc/bind/zones.rfc1918 add

_acme-challenge IN NS ns1.midworld.de.
_acme-challenge IN NS ns2.midworld.de.

/etc/bind/named.conf add

zone "_acme-challenge.DOMAIN1.de" {
        type master;
        file "/var/bind/dyn/_acme-challenge.DOMAIN1.de.zone";
        allow-query { any; };
        allow-update { localhost; };
        
};

zone "_acme-challenge.DOMAIN2.de" {
        type master;
        file "/var/bind/dyn/_acme-challenge.DOMAIN2.de.zone";
        allow-query { any; };
        allow-update { localhost; };
        
};

You have to add all domains you want to auto-update the certificates.

# service bind9 restart

2. Edit VM with Letsencrypt installation

• # mkdir /opt/letsencrypt
• copy the 2 files from repository (scripts/letsencrypt) to /opt/letsencrypt
• dns-auth.sh: change line 11 to your above new created VM-IP
• auto-renew.sh: change email and domain to your needs in every line. You have to add 1 line for every domain you want to auto-update the certs. This have to be similar with the above /etc/bind/named.conf
• # chown +x /opt/letsencrypt/dns-auto.sh
• # chown +x /opt/letsencrypt/auto-renew.sh
• # crontab -e
• add 35 3 1 * * /bin/bash /opt/letsencrypt/auto-renew.sh >/dev/null 2>&1

3. Edit Proxmox Server (optional)

If you want to run your new installed VM only on certificate-update get through the following steps:

• # mkdir /opt/cronvm
• copy the 1 file from repository (scripts/proxmox) to /opt/cronvm
• # chown +x /opt/cronvm/controlvm.sh
• # crontab -e
• add and edit [XXX] to the ID of your in step 1 installed VM

30 3 1 * * bash -x /opt/cronvm/controlvm.sh start XXX >/dev/null 2>&1
59 3 1 * * bash -x /opt/cronvm/controlvm.sh shutdown XXX >/dev/null 2>&1