Set up SmartDNS in Alpine Linux (LXC)

smartdns-banner.png

SmartDNS is a local DNS server that retrieves DNS query results from multiple upstream DNS servers and delivers the fastest results to clients.
It supports secure DNS protocols such as DoT (DNS over TLS) and DoH (DNS over HTTPS), providing enhanced privacy protection, avoiding DNS pollution, and improving network access speed.
Additionally, SmartDNS supports high-performance ad filtering for an overall better browsing experience

• Multiple upstream DNS servers
• Return the fastest IP address
• Support for multiple query protocols
• Domain IP address specification
• Domain name high-performance rule filtering
• Linux/Windows multi-platform support
• Support IPV4, IPV6 dual stack
• DNS64
• High performance, low resource consumption
• DNS domain forwarding

Architecture

architecture.png

Here is how to install SmartDNS on Alpine Linux running in a Proxmox VE LXC container

Download the latest version of SmartDNS from official website

wget https://github.com/pymumu/smartdns/releases/download/Release42/smartdns.1.2023.05.07-1641.x86_64-linux-all.tar.gz

Connecting to github.com (20.205.243.166:443)
Connecting to objects.githubusercontent.com (185.199.111.133:443)
saving to 'smartdns.1.2023.05.07-1641.x86_64-linux-all.tar.gz'
smartdns.1.2023.05.0 100% || 1628k 0:00:00 ETA
'smartdns.1.2023.05.07-1641.x86_64-linux-all.tar.gz' saved

Start to install

tar -zxf smartdns.1.2023.05.07-1641.x86_64-linux-all.tar.gz && cd smartdns/ && chmod +x ./install
./install -i

created directory: '/etc/smartdns'
'usr/sbin/smartdns' -> '/usr/sbin/smartdns'
'etc/smartdns/smartdns.conf' -> '/etc/smartdns/smartdns.conf'
install: can't create '/etc/default/smartdns': No such file or directory

copy the execute file to binaries with superuser (root) privileges directory

cp ~/smartdns/usr/sbin/smartdns /usr/sbin/

backup original SmartDNS configuration file

mv /etc/smartdns/smartdns.conf /etc/smartdns/smartdns.conf.bak

create a new SmartDNS configuration file

Official reference: https://pymumu.github.io/smartdns/en/config/basic-config/

cat >> /etc/smartdns/smartdns.conf << EOF
server-name smartdns
bind :53
bind-tcp :53
cache-size 3096
cache-file /tmp/smartdns.cache
cache-persist yes
tcp-idle-time 120
rr-ttl 600
rr-ttl-min 60
rr-ttl-max 600
rr-ttl-reply-max 60
local-ttl 60
prefetch-domain yes
max-reply-ip-num 1
log-level info
log-size 128K
#-------dns-----------
server-https https://cloudflare-dns.com/dns-query
server-tls 1.1.1.1:853
server-tls 8.8.4.4:853
server-tls 9.9.9.9:853
server-tcp 114.114.114.114:53
server-tcp 223.5.5.5:53
server-tcp 180.76.76.76:53
server-tcp 202.99.160.68:53
server-tpc 8.8.4.4:53                            
server-tpc 9.9.9.9:53        
#----------------            
speed-check-mode ping,tcp:80,tcp:443
response-mode fastest-ip            
serve-expired yes                   
force-AAAA-SOA yes 
EOF

Disable DNS queries from UDHCP

sed -i 's/^RESOLV_CONF/#RESOLV_CONF/' /usr/share/udhcpc/default.script

Update the nameserver to localhost from /etc/resolv.conf in the PVE's LXC

2023-05-11_112825.png

Enable the service to start on boot

echo 'nohup /usr/sbin/smartdns -f -c /etc/smartdns/smartdns.conf >/dev/null 2>&1 &' >> /etc/local.d/smartdns.start
chmod +x /etc/local.d/smartdns.start
rc-update add local

Now Apply setting and functions by reboot

reboot

Create a new systemd service file at /etc/init.d/smartdns

touch /etc/init.d/smartdns
chmod +x /etc/init.d/smartdns

Add the following content to the file:

cat >> /etc/init.d/smartdns << EOF
#!/sbin/openrc-run

name="SmartDNS"
command="/usr/sbin/smartdns"
command_args="-c /etc/smartdns/smartdns.conf"
pidfile="/var/run/smartdns.pid"

depend() {
    need net
    after firewall
}
EOF

Save and exit the text editor.

Enable and start SmartDNS

rc-update add smartdns default
rc-service smartdns start

Now, set to start on boot on your Alpine Linux system.

SmartDNS can block ads by returning SOA for the corresponding domain name.
Official reference: https://pymumu.github.io/smartdns/en/config/ad-block/

Create a script to download the anti-ad-smartdns.conf file from the community URL

cat >> /root/adblock-smartdns-conf.sh << EOF
#!/bin/bash
wget https://github.com/privacy-protection-tools/anti-AD/blob/master/anti-ad-smartdns.conf -O /etc/smartdns/anti-ad-smartdns.conf
EOF

Make the script executable:

chmod +x /root/adblock-smartdns-conf.sh

Open the crontab editor:

crontab -e

Add the following line to the end of the file to run the script every day at 1:00 AM:

0 1 * * * /root/adblock-smartdns-conf.sh

Modify the /etc/smartdns/smartdns.conf file to include the above configuration file:

conf-file /etc/smartdns/anti-ad-smartdns.conf

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