resolved - DNS server

A typical usage of resolved will look like:

sudo /path/to/resolved --cache-size 1000000     \
                       -Z /path/to/config/zones \
                       -A /path/to/your/hosts   \
                       -Z /path/to/your/zones

See --help for a full listing of command-line options (most of which can also be specified via environment variables), and also the configuration documentation and guides.

Monitoring

Prometheus metrics are exposed at http://127.0.0.1:9420/metrics by default.

Logs are emitted to stdout. Control the log level with the RUST_LOG environment variable:

• RUST_LOG=trace - verbose messages useful for development, like "entered function X"
• RUST_LOG=debug - warns about strange but recoverable situations, like "socket read error"
• RUST_LOG=info - gives top-level information, like "new connection" or "reloading configuration"
• RUST_LOG=warn - warns about recoverable internal errors and invalid configuration, like "could not serialise message" or "invalid record in cache"
• RUST_LOG=error - warns about fatal errors and then terminates the process, like "could not bind socket"

You can also set the log level per component. A good default RUST_LOG definition is dns_resolver=info,resolved=info.

Set the log format with the RUST_LOG_FORMAT environment variable, which is a sequence of comma-separated values:

• One of full (default), compact, pretty, or json - see the tracing_subscriber crate
• One of ansi (default), no-ansi
• One of time (default), no-time

If running under systemd (or some other processor supervisor which automatically adds timestamps), a good default RUST_LOG_FORMAT definition is json,no-time.

Permissions

DNS uses port 53 (both UDP and TCP). So resolved must be run as root or with the CAP_NET_BIND_SERVICE capability.

Signals

SIGUSR1 - reload the configuration