Unbound automatic bash install script for proxmox

unbound-install.sh

#!/bin/bash

n='([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])'
m='([0-9]|[12][0-9]|3[012])'

echo -n "Updating repos: "
apt -q update &> /dev/null
echo "done"

echo -n "Updating system: "
apt -q -y upgrade &> /dev/null
echo "done"

echo -e "Installing unbound: (1/2)"
apt -q -y install unbound &> /dev/null
echo -e "\rInstalling unbound: (2/2)"
apt -q -y install apparmor &> /dev/null
echo -e "\rInstalling unbound: done"

echo -n "Getting DNS ROOT Servers: "
wget https://www.internic.net/domain/named.root -qO- | tee /var/lib/unbound/root.hints &> /dev/null
echo "done"

echo -e "\nUser variables:\n "
read -p "Enter listen ip (def: 127.0.0.1):> " DNS_IP

if ! [[ $DNS_IP =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
  read -p "False, listen ip (def: 127.0.0.1):> " DNS_IP
fi

read -p "Enter listen port (default: 5335):> " DNS_PORT

if ! [[ $DNS_PORT =~ ^[0-9]+$ ]]
then
    read -p "False, please enter only numbers:> " DNS_PORT
elif [[ ${#DNS_PORT} -gt 5 ]]
then
   read -p "False, please enter an max lenght of 5:> " DNS_PORT
fi

read -p "Enter private ip (CIDR/range):> " DNS_PRIV
if ! [[ $DNS_PRIV =~ ^$n(\.$n){3}/$m$ ]]; then
    read -p "False, enter in CIDR/range:> " DNS_PRIV
fi

read -p "Enable logging? (y/N):> " DNS_LOG
if [ $DNS_LOG == "y" ] || [ $DNS_LOG == "Y" ]; then

        echo "Please enter path+name for logfile (leave empty for default)"

        read -rp "Default? /var/log/unbound/unbound.log:> " DNS_LOG_DEF
        if [[ ${#DNS_LOG_DEF} -lt 1 ]]; then
                DNS_LOG_FILE="/var/log/unbound/unbound.log"
        else
                DNS_LOG_FILE=$DNS_LOG_DEF
        fi

        read -rp "Enter Loglevel (1-5):> " DNS_LOG_LVL
        if [[ ${DNS_LOG_LVL} -gt 5 ]] || [[ ${DNS_LOG_LVL} -lt 1 ]]; then
                read -rp "False, valid between 1 and 5:> " DNS_LOG_LVL
        fi
else
        DNS_LOG_STAT="# logfile:"
        DNS_LOG_FILE="/var/log/unbound/unbound.log"
        DNS_LOG_LVL=0
fi

echo -n "Checking for log directory: "
DNS_LOG_STAT="logfile:"
DNS_LOG_PATH="$(dirname ${DNS_LOG_FILE})"

if [ -d ${DNS_LOG_PATH} ]; then
    if ! [ -f ${DNS_LOG_FILE} ]; then
        touch ${DNS_LOG_FILE}
        echo "Logfile created."
    else
        echo "Logfile exists."
    fi
else
    mkdir -p ${DNS_LOG_PATH}
    touch ${DNS_LOG_FILE}
    echo "Logfile and directory created."
fi

echo -n "Chowning logfile: "
chown unbound:unbound ${DNS_LOG_FILE} &> /dev/null
echo "done"

PICONF="/etc/unbound/unbound.conf.d/pi-hole.conf"

echo -n "Generate config file: "
cat <<EOF >${PICONF}
server:
    # If no logfile is specified, syslog is used
    ${DNS_LOG_STAT} "$DNS_LOG_FILE"

    # Level 0 means no verbosity, only errors
    # Level 1 gives operational information
    # Level 2 gives  detailed operational  information
    # Level 3 gives query level information
    # Level 4 gives  algorithm  level  information
    # Level 5 logs client identification for cache misses
    verbosity: ${DNS_LOG_LVL}

    # Answer queries from
    # The local machine
    interface: 127.0.0.1
    interface: ::1
    # The local machine on the network
    interface: ${DNS_IP}

    # Default DNS port
    port: ${DNS_PORT}
    
    # Save in cache for an hour to a day
    cache-min-ttl: 3600
    cache-max-ttl: 86400

    # Enable IPv4, IPv6, UDP and TCP requests
    do-ip4: yes
    do-ip6: no        # May be set to yes if you have IPv6 connectivity
    do-udp: yes
    do-tcp: yes

    # You want to leave this to no unless you have *native* IPv6. With 6to4 and
    # Terredo tunnels your web browser should favor IPv4 for the same reasons
    prefer-ip6: no

    # Use this only when you downloaded the list of primary root servers!
    # If you use the default dns-root-data package, unbound will find it automatically
    root-hints: "/var/lib/unbound/root.hints"

    # Trust glue only if it is within the server's authority
    harden-glue: yes

    # Require DNSSEC data for trust-anchored zones, if such data is absent, the zone becomes BOGUS
    harden-dnssec-stripped: yes

    # Don't use Capitalization randomization as it known to cause DNSSEC issues sometimes
    # see https://discourse.pi-hole.net/t/unbound-stubby-or-dnscrypt-proxy/9378 for further details
    use-caps-for-id: no

    # Reduce EDNS reassembly buffer size.
    # IP fragmentation is unreliable on the Internet today, and can cause
    # transmission failures when large DNS messages are sent via UDP. Even
    # when fragmentation does work, it may not be secure; it is theoretically
    # possible to spoof parts of a fragmented DNS message, without easy
    # detection at the receiving end. Recently, there was an excellent study
    # >>> Defragmenting DNS - Determining the optimal maximum UDP response size for DNS <<<
    # by Axel Koolhaas, and Tjeerd Slokker (https://indico.dns-oarc.net/event/36/contributions/776/)
    # in collaboration with NLnet Labs explored DNS using real world data from the
    # the RIPE Atlas probes and the researchers suggested different values for
    # IPv4 and IPv6 and in different scenarios. They advise that servers should
    # be configured to limit DNS messages sent over UDP to a size that will not
    # trigger fragmentation on typical network links. DNS servers can switch
    # from UDP to TCP when a DNS response is too big to fit in this limited
    # buffer size. This value has also been suggested in DNS Flag Day 2020.
    edns-buffer-size: 1232

    # Perform prefetching of close to expired message cache entries
    # This only applies to domains that have been frequently queried
    prefetch: yes

    # One thread should be sufficient, can be increased on beefy machines. In reality for most users running on small networks or on a single machine, it should be unnecessary to seek performance enhancement by increasing num-threads above 1.
    num-threads: 1

    # Ensure kernel buffer is large enough to not lose messages in traffic spikes
    so-rcvbuf: 1m
    
    # Privacy
    # Hide identity and version
    hide-identity: yes
    hide-version: yes

    # Ensure privacy of local IP ranges
    # Localhost
    private-address: 127.0.0.1
    private-address: ::1
    # Windows
    # private-address: 169.254.0.0/16
    # private-address: 172.16.0.0/12
    # Network
    private-address: ${DNS_PRIV}
    # private-address: 2001:db8::/108
    # Vpn
    # private-address: 10.0.0.0/8
    # private-address: fd00::/8

    # Prevent from resolving network IPs
    do-not-query-address: ${DNS_PRIV}
    do-not-query-localhost: yes

    # Launch in a deamon (temporarily disabled)
    # do-daemonize: yes

    # Access control
    # Deny all the Internet (temporarily refuse)
    access-control: 0.0.0.0/0 refuse
    access-control: ::0/0 refuse
    # Allow localhost
    access-control: 127.0.0.1 allow
    access-control: ::1 allow
    # Allow from network CIDR
    access-control: ${DNS_PRIV} allow_snoop
    
    # Prefetch old-cached DNS responses
    prefetch: yes
EOF
echo "done"
echo ""
echo -n "Restarting unbound service: "
service unbound restart
echo "done"

echo -n "Testing configuration: "

        TESTENV="$(dig pi-hole.net @${DNS_IP} -p ${DNS_PORT} | grep status | cut -d ':' -f3 | cut -d ',' -f1)"

        if [[ "${TESTENV}" -eq "NOERROR" ]]; then
                echo "success"
        else
                echo "failed! Please recheck configuration."
        fi

echo -n "Checking for piHole on local server: "
if ! command -v pihole &> /dev/null
then
    echo "not found."
    echo ""
    echo "Please add \"edns-packet-max=1232\" into \"/etc/dnsmasq.d/99-edns.conf\" on your piHole server."
    echo ""
else
    echo "found."
    echo -n "Inform piHole(FTL/dnsmasq): "
    touch /etc/dnsmasq.d/99-edns.conf
    echo "edns-packet-max=1232" > "/etc/dnsmasq.d/99-edns.conf"
    echo "done"
fi

echo -n "Disable openresolver: "
systemctl disable unbound-resolvconf.service &> /dev/null
systemctl stop unbound-resolvconf.service &> /dev/null
echo "done"

echo -n "Apply appamor settings: "
echo "/var/log/unbound/unbound.log rw," >> "/etc/apparmor.d/local/usr.sbin.unbound"
apparmor_parser -r /etc/apparmor.d/usr.sbin.unbound &> /dev/null
echo "done"

echo -n "Restarting unbound: "
service unbound stop &> /dev/null
sleep 1
service unbound start &> /dev/null
echo "done"

echo ""
echo -e "Finally, configure Pi-hole to use your recursive DNS server\nby specifying 127.0.0.1#5335 as the Custom DNS (IPv4):\n"
echo ">>> https://docs.pi-hole.net/images/RecursiveResolver.png"