coredns/plugin/erratic

erratic

Name

erratic - a plugin useful for testing client behavior.

Description

erratic returns a static response to all queries, but the responses can be delayed, dropped or truncated. The erratic plugin will respond to every A or AAAA query. For any other type it will return a SERVFAIL response (except AXFR). The reply for A will return 192.0.2.53 (RFC 5737), for AAAA it returns 2001:DB8::53 (RFC 3849). For an AXFR request it will respond with a small zone transfer.

Syntax

erratic {
    drop [AMOUNT]
    truncate [AMOUNT]
    delay [AMOUNT [DURATION]]
}

• drop: drop 1 per AMOUNT of queries, the default is 2.
• truncate: truncate 1 per AMOUNT of queries, the default is 2.
• delay: delay 1 per AMOUNT of queries for DURATION, the default for AMOUNT is 2 and the default for DURATION is 100ms.

In case of a zone transfer and truncate the final SOA record isn't added to the response.

Ready

This plugin reports readiness to the ready plugin.

Examples

example.org {
    erratic {
        drop 3
    }
}

Or even shorter if the defaults suit you. Note this only drops queries, it does not delay them.

example.org {
    erratic
}

Delay 1 in 3 queries for 50ms

example.org {
    erratic {
        delay 3 50ms
    }
}

Delay 1 in 3 and truncate 1 in 5.

example.org {
    erratic {
        delay 3 5ms
        truncate 5
    }
}

Drop every second query.

example.org {
    erratic {
        drop 2
        truncate 2
    }
}

See Also

RFC 3849 and RFC 5737.