Replace the resolvectl-only fips-dns.service with a detection script
that configures whichever DNS resolver is available:
1. systemd dns-delegate (systemd >= 258, declarative drop-in)
2. systemd-resolved via resolvectl (most systemd distros)
3. dnsmasq (standalone)
4. NetworkManager with dnsmasq plugin
5. Warning with manual instructions if none found
Service reloads are non-fatal — config is written and the backend
is recorded even if the reload fails, preventing state file cleanup
issues under set -e.
Teardown reads the recorded backend from /run/fips/dns-backend and
reverses the configuration, or cleans up all possible backends if
the state file is missing.
Includes a Docker-based test harness (testing/dns-resolver/test.sh)
covering all five backends across Debian 12, Debian 13, Fedora,
and bare systems.
Fixes#52.
The fips-dns.service unit had three issues:
1. Wants=systemd-resolved.service caused systemd to start systemd-resolved
on systems that weren't using it, breaking existing DNS by rewriting
/etc/resolv.conf to the stub resolver at 127.0.0.53.
2. The ExecStart busy-wait loop for fips0 had no timeout, hanging forever
if fips.service failed to create the TUN device.
3. Installers unconditionally enabled fips-dns.service regardless of whether
systemd-resolved was present.
Fix by replacing Wants= with ConditionPathExists=/run/systemd/resolve (skips
cleanly if resolved isn't running), adding Requires=fips.service (won't start
without the daemon), bounding the fips0 wait loop to 30 seconds, and making
the installers conditional on systemd-resolved being active.
Packaging directory structure:
- packaging/common/ — shared config (fips.yaml) used by all formats
- packaging/systemd/ — systemd-specific installer and service units
Systemd packaging includes:
- build-tarball.sh: builds release binaries and creates a self-contained
install tarball with stripped binaries
- fips.service: systemd unit running the daemon with security hardening
- fips-dns.service: oneshot unit configuring resolvectl to route .fips
domain queries to the FIPS DNS shim on 127.0.0.1:5354
- install.sh: deploys binaries to /usr/local/bin, installs systemd units,
creates fips group for non-root control socket access
- uninstall.sh: removes service and binaries, optional --purge for
config and identity key files
- README.install.md: installation and configuration guide
Default config enables UDP (2121), TCP inbound (8443), TUN, and DNS
resolver. Identity is ephemeral by default for privacy; operators can
uncomment persistent: true to maintain a stable npub for static peer
publishing. Ethernet transport is commented out for per-node setup.
Johnathan CorganandGitHub