coredns/plugin/erratic
Miek Gieben 898b1ef316 server: actually scrub response (#2225)
* server: actually scrub response

Did all the worked, hooked it up wrongly :(

This also needs test, but those are hard(er) because we only receive
packets after they have been decoded; i.e. we never see the wirefmt.

Signed-off-by: Miek Gieben <miek@miek.nl>

* Add tests

Add a test for checking is compression pointers are set in the packet.
This also adds an undocumented 'large' feature to the erratic plugin to
send large responses that should be compressed.

Commenting the Scrub out in server results in:

=== RUN   TestCompressScrub
--- FAIL: TestCompressScrub (0.00s)
    compression_scrub_test.go:41: Expected returned packet to be < 512, got 839
FAIL
exit status 1
FAIL    github.com/coredns/coredns/test 0.036s

Actually checking the size might be easier, but lets be thorough here
and check the pointers them selves.

Signed-off-by: Miek Gieben <miek@miek.nl>

* Fix tests

Signed-off-by: Miek Gieben <miek@miek.nl>

* plugin erratic: fix e.large

always put an rr in the reply, fix e.large in erractic and add test to
check for it.

Signed-off-by: Miek Gieben <miek@miek.nl>
2018-10-23 09:55:40 -07:00
..
autopath.go Remove the word middleware (#1067) 2017-09-14 09:36:06 +01:00
erratic.go server: actually scrub response (#2225) 2018-10-23 09:55:40 -07:00
erratic_test.go server: actually scrub response (#2225) 2018-10-23 09:55:40 -07:00
health.go plugin/health: implement dyn health checks (#1214) 2017-11-13 09:52:40 +00:00
log_test.go Clean up tests logging (#1979) 2018-07-19 16:23:06 +01:00
OWNERS Add OWNERS file (#1486) 2018-02-08 10:55:51 +00:00
README.md plugin/erratic: add axfr support (#1977) 2018-07-20 10:25:54 +01:00
setup.go server: actually scrub response (#2225) 2018-10-23 09:55:40 -07:00
setup_test.go just use setup (#1574) 2018-02-28 19:56:14 -08:00
xfr.go plugin/erratic: add axfr support (#1977) 2018-07-20 10:25:54 +01:00

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. The reply for A will return 192.0.2.53 (see RFC 5737, for AAAA it returns 2001:DB8::53 (see RFC 3849) and for an AXFR request it will respond with a small zone transfer.

erratic can also be used in conjunction with the autopath plugin. This is mostly to aid in testing.

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.

Health

This plugin implements dynamic health checking. For every dropped query it turns unhealthy.

Examples

. {
    erratic {
        drop 3
    }
}

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

. {
    erratic
}

Delay 1 in 3 queries for 50ms

. {
    erratic {
        delay 3 50ms
    }
}

Delay 1 in 3 and truncate 1 in 5.

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

Drop every second query.

. {
    erratic {
        drop 2
        truncate 2
    }
}

Also See

RFC 3849 and RFC 5737.