Mirrors/coredns
1
0
Fork 0
mirror of https://github.com/coredns/coredns.git synced 2025-10-27 00:04:15 -04:00
Code Issues Packages Projects Releases Wiki Activity

auto make -f Makefile.doc

Browse Source
This commit is contained in:
coredns-auto-go-mod-tidy[bot]
2020-03-31 14:18:39 +00:00
parent d4cac0c43a
commit db1d4f91da
37 changed files with 80 additions and 61 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
man/coredns-autopath.7
View File

@@ -1,5 +1,5 @@
.\" Generated by Mmark Markdown Processer - mmark.miek.nl
.TH "COREDNS-AUTOPATH" 7 "January 2020" "CoreDNS" "CoreDNS Plugins"
.TH "COREDNS-AUTOPATH" 7 "March 2020" "CoreDNS" "CoreDNS Plugins"
.SH "NAME"
.PP
@@ -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
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.
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.