coredns/man/coredns-erratic.7

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.TH "COREDNS-ERRATIC" 7 "August 2019" "CoreDNS" "CoreDNS Plugins"

.SH "NAME"
.PP
\fIerratic\fP - a plugin useful for testing client behavior.

.SH "DESCRIPTION"
.PP
\fIerratic\fP returns a static response to all queries, but the responses can be delayed, dropped or truncated.
The \fIerratic\fP 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
\[la]https://tools.ietf.org/html/rfc5737\[ra],
for AAAA it returns 2001:DB8::53 (see RFC 3849
\[la]https://tools.ietf.org/html/rfc3849\[ra]) and for an
AXFR request it will respond with a small zone transfer.

.PP
\fIerratic\fP can also be used in conjunction with the \fIautopath\fP plugin. This is mostly to aid in
testing.

.SH "SYNTAX"
.PP
.RS

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

.fi
.RE

.IP \(bu 4
\fB\fCdrop\fR: drop 1 per \fBAMOUNT\fP of queries, the default is 2.
.IP \(bu 4
\fB\fCtruncate\fR: truncate 1 per \fBAMOUNT\fP of queries, the default is 2.
.IP \(bu 4
\fB\fCdelay\fR: delay 1 per \fBAMOUNT\fP of queries for \fBDURATION\fP, the default for \fBAMOUNT\fP is 2 and
the default for \fBDURATION\fP is 100ms.


.PP
In case of a zone transfer and truncate the final SOA record \fIisn't\fP added to the response.

.SH "READY"
.PP
This plugin reports readiness to the ready plugin.

.SH "EXAMPLES"
.PP
.RS

.nf
\&. {
    erratic {
        drop 3
    }
}

.fi
.RE

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

.PP
.RS

.nf
\&. {
    erratic
}

.fi
.RE

.PP
Delay 1 in 3 queries for 50ms

.PP
.RS

.nf
\&. {
    erratic {
        delay 3 50ms
    }
}

.fi
.RE

.PP
Delay 1 in 3 and truncate 1 in 5.

.PP
.RS

.nf
\&. {
    erratic {
        delay 3 5ms
        truncate 5
    }
}

.fi
.RE

.PP
Drop every second query.

.PP
.RS

.nf
\&. {
    erratic {
        drop 2
        truncate 2
    }
}

.fi
.RE

.SH "ALSO SEE"
.PP
RFC 3849
\[la]https://tools.ietf.org/html/rfc3849\[ra] and
RFC 5737
\[la]https://tools.ietf.org/html/rfc5737\[ra].