@@ -13,6 +13,9 @@ failures, the original reply is returned. Because \fIautopath\fP returns a reply
the original question it will add a CNAME that points from the original name (with the search path
element in it) to the name of this answer.
.PP
\fBNote\fP: There are several known issues. See section below.
.SH "SYNTAX"
.PP
.RS
...
...
@@ -39,7 +42,7 @@ If a plugin implements the \fB\fCAutoPather\fR interface then it can be used.
If monitoring is enabled (via the \fIprometheus\fP plugin) then the following metric is exported:
.IP \(bu 4
\fB\fCcoredns_autopath_success_count_total{server}\fR - counter of successfully autopath-ed queries.
\fB\fCcoredns_autopath_success_total{server}\fR - counter of successfully autopath-ed queries.
.PP
...
...
@@ -73,8 +76,19 @@ Use the search path dynamically retrieved from the \fIkubernetes\fP plugin.
.SH "KNOWN ISSUES"
.PP
In Kubernetes, \fIautopath\fP is not compatible with pods running from Windows nodes.
In Kubernetes, \fIautopath\fP can derive the wrong namespace of a client Pod (and therefore wrong search path)
in the following case. To properly build the search path of a client \fIautopath\fP needs to
know the namespace of the a Pod making a DNS request. To do this, it relies on the
\fIkubernetes\fP plugin's Pod cache to resolve the client's IP address to a Pod. The Pod cache is maintained by
an API watch on Pods. When Pod IP assignments change, the Kubernetes API notifies CoreDNS via the API watch.
However, that notification is not instantaneous. In the case that a Pod is deleted, and it's IP is
immediately provisioned to a Pod in another namespace, and that new Pod make a DNS lookup \fIbefore\fP the API watch
can notify CoreDNS of the change, \fIautopath\fP will resolve the IP to the previous Pod's namespace.
.PP
In Kubernetes, \fIautopath\fP is not compatible with Pods running from Windows nodes.
.PP
If the server side search ultimately results in a negative answer (e.g. \fB\fCNXDOMAIN\fR), then the client will fruitlessly search all paths manually, thus negating the \fIautopath\fP optimization.
If the server side search ultimately results in a negative answer (e.g. \fB\fCNXDOMAIN\fR), then the client will
fruitlessly search all paths manually, thus negating the \fIautopath\fP optimization.
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