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OpenNIC DNS updater script

opennic-resolve-up-

This script will fetch a current list of DNS servers from api.opennicproject.org, filter them by countries if desired, sort by percentage, and write the result to files readable by various resolvers.

Thoroughly tested and in daily use on Archlinux & Debian stable.
This version requires name resolution to be already working when executed.
OpenNIC's geoip sorting is known to be unreliable, therefore this script attempts to fetch a larger list, then sort it by reliability percentage, and optionally filter by countries. It is capable of writing different formats (systemd, resolvconf) to multiple files.
Systemd unit files (service and timer) are provided.

Installation-up-

For ArchLinux compatible distros, opennic-resolve is will soon be in the AUR.

Users of other distros can run ./install.sh -h for installation options.

After installation, execute the service with

systemctl start opennic-resolve.service

And start the timer with

systemctl enable --now opennic-resolve.timer

--help output-up-

This script will fetch a current list of DNS servers from api.opennicproject.org,
filter them by countries if desired, sort by percentage, and write the result
to files readable by various resolvers.
It will then restart some systemd services if they are active. If the systemctl
executable is not found in PATH, the script will gracefully exit instead.

The script takes no command line options (except "-h" which produces this
output, everything else is discarded), but searches for a config file in
"$HOME/.config/opennic-resolve/opennic-resolve.conf"
"/etc/opennic-resolve/opennic-resolve.conf"
"@[_symlinks/opennic-resolve_README.md].conf" i.e. the full path to the script + .conf
"$PWD/opennic-resolve.conf" i.e. in the present working directory
Whichever is encountered first will be the only one to parse.

Defaults and possible configuration:

countries=  Provide a comma-separated list of 2-letter country codes.
            Nameservers from other countries won't be added to the file.
            Empty by default - no filtering by country.

max=        Maximum number of entries to write to a file. Default: 5
            Must be between 2 and 50, although it appears that the API rarely
            returns more than 20 results anyhow.

min=        Minimum number of entries to write to a file. Default: 2
            If fewer nameservers are found no file will be overwritten.

timeout=    Timeout in s for data fetching from api.opennicproject.org. default: 10

out=        Comma-separated list of actions. Possible values:
            resolvconf
                each line is either a comment starting with "#" or
                "nameserver " followed by the IP of the nameserver
            resolved
                starts with "[Resolve]", after which each line is either a
                comment starting with "#" or "DNS=" followed by the IP
                of the nameserver
            networkd
                starts with "[Network]", after which each line is either a
                comment starting with "#" or "DNS=" followed by the IP
                of the nameserver
            Overrides the default, which is "resolvconf,resolved"

resolvconf= Write to this file instead of /etc/resolv.conf
networkd=   Write networkd syntax to this file (no default)
resolved=   Write to this file instead of /etc/systemd/resolved.conf.d/dns.conf

services=   Comma-separated list of systemd services to restart, if active.
            Overrides the default, which is:
            "systemd-networkd.service,systemd-resolved.service"

More information:
https://notabug.org/ohnonot/opennic https://framagit.org/ohnonot/opennic

Keep in mind that various software can override nameservers defined in this way, e.g.:
NetworkManager, netctl, dnsmasq, openresolv, resolvconf, systemd-resolvconf ...
So you might want to disable these.

If you rely only on dhcpcd to connect to the internet:

dhcpcd-up-

It typically relies on /etc/resolv.conf for name resolution. No service restart is required in this case, but make sure that nothing overwrites this file:

  • Add the option nohook resolv.conf to /etc/dhcpcd.conf.
  • Make sure /etc/dhcpcd.conf does not define any nameservers.
  • Make sure dhcpcd triggers no other software that might overwrite /etc/resolv.conf.

Further reading: https://wiki.archlinux.org/index.php/Dhcpcd#/etc/resolv.conf

Dependencies-up-

  • jq to parse json
  • curl
  • coreutils