coredns/man/coredns-erratic.7

.\" generated with Ronn/v0.7.3
.\" http://github.com/rtomayko/ronn/tree/0.7.3
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.TH "COREDNS\-ERRATIC" "7" "March 2019" "CoreDNS" "CoreDNS plugins"
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.SH "NAME"
\fIerratic\fR \- a plugin useful for testing client behavior\.
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.SH "DESCRIPTION"
\fIerratic\fR returns a static response to all queries, but the responses can be delayed, dropped or truncated\. The \fIerratic\fR 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 \fIhttps://tools\.ietf\.org/html/rfc5737\fR, for AAAA it returns 2001:DB8::53 (see RFC 3849 \fIhttps://tools\.ietf\.org/html/rfc3849\fR) and for an AXFR request it will respond with a small zone transfer\.
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.P
\fIerratic\fR can also be used in conjunction with the \fIautopath\fR plugin\. This is mostly to aid in testing\.
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.SH "SYNTAX"
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.nf

erratic {
    drop [AMOUNT]
    truncate [AMOUNT]
    delay [AMOUNT [DURATION]]
}
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.fi
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.IP "\(bu" 4
\fBdrop\fR: drop 1 per \fBAMOUNT\fR of queries, the default is 2\.
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.IP "\(bu" 4
\fBtruncate\fR: truncate 1 per \fBAMOUNT\fR of queries, the default is 2\.
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.IP "\(bu" 4
\fBdelay\fR: delay 1 per \fBAMOUNT\fR of queries for \fBDURATION\fR, the default for \fBAMOUNT\fR is 2 and the default for \fBDURATION\fR is 100ms\.
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.IP "" 0
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.P
In case of a zone transfer and truncate the final SOA record \fIisn\'t\fR added to the response\.
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.SH "HEALTH"
This plugin implements dynamic health checking\. For every dropped query it turns unhealthy\.
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.SH "EXAMPLES"
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.nf

\&\. {
    erratic {
        drop 3
    }
}
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.fi
.
.P
Or even shorter if the defaults suits you\. Note this only drops queries, it does not delay them\.
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.IP "" 4
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.nf

\&\. {
    erratic
}
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.fi
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.IP "" 0
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.P
Delay 1 in 3 queries for 50ms
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.IP "" 4
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.nf

\&\. {
    erratic {
        delay 3 50ms
    }
}
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.fi
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.IP "" 0
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.P
Delay 1 in 3 and truncate 1 in 5\.
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.IP "" 4
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.nf

\&\. {
    erratic {
        delay 3 5ms
        truncate 5
    }
}
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.fi
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.IP "" 0
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.P
Drop every second query\.
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.IP "" 4
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.nf

\&\. {
    erratic {
        drop 2
        truncate 2
    }
}
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.fi
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.IP "" 0
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.SH "ALSO SEE"
RFC 3849 \fIhttps://tools\.ietf\.org/html/rfc3849\fR and RFC 5737 \fIhttps://tools\.ietf\.org/html/rfc5737\fR\.