README
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Kubernetes LoadBalancer
Name
k8s_loadbalancer - Exports Services of type LoadBalancer to external DNS
Description
The plugin currently takes services of type LoadBalancer from all namespaces and exports it to the .kube. zone. For example:
Service Name: test-wordpress
DNS: test-wordpress.kube
This can be configured as shown in the configuration section below.
Compilation
This package will always be compiled as part of CoreDNS and not in a standalone way. It will require you to use go get or as a dependency on plugin.cfg.
The manual will have more information about how to configure and extend the server with external plugins.
A simple way to consume this plugin, is by adding the following on plugin.cfg, and recompile it as detailed on coredns.io.
k8s_loadbalancer:k8s_loadbalancer
Put this early in the plugin list, so that example is executed before any of the other plugins.
After this you can compile coredns by:
go generate
go build
Or you can instead use make:
make
Syntax
example
Metrics
If monitoring is enabled (via the prometheus directive) the following metric is exported:
coredns_example_request_count_total{server}- query count to the example plugin.
The server label indicated which server handled the request, see the metrics plugin for details.
Ready
This plugin reports readiness to the ready plugin. It will be immediately ready.
Examples
In this configuration, we forward all queries to 8.8.8.8 and resolve anything going to the .kube zone.
. {
k8s_loadbalancer
forward . 8.8.8.8
debug
}
Or without any external connectivity:
. {
k8s_loadbalancer
}
Without any zones being specified, the plugin will default to the .kube. zone. Additional zones can be added as below (This will add the test, and test2 zones)
. {
k8s_loadbalancer .test. .test2. {
enableNSZone true
enableRootZone true
kubeConfigPath /path/to/.kube/config
}
}
Additonally Namespace Zones can be enabled for example:
service.namespace.zone
This can be done using the enableNSZone flag (true/false)
Also See
See the manual.
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type LoadBalancer ¶
type LoadBalancer struct {
PluginReady bool
KubeConfigPath string
EnableRootZone bool
EnableNSZone bool
RootZones []string
RecordsSync *sync.Mutex
Records []kubeRecord
Next plugin.Handler
}
LoadBalancer is a plugin to show how to write a plugin.
func NewLoadBalancer ¶
func NewLoadBalancer() *LoadBalancer
func (LoadBalancer) Name ¶
func (e LoadBalancer) Name() string
Name implements the Handler interface.
func (LoadBalancer) Ready ¶
func (e LoadBalancer) Ready() bool
Ready implements the ready.Readiness interface, once this flips to true CoreDNS assumes this plugin is ready for queries; it is not checked again.
func (LoadBalancer) RemoveZoneSuffix ¶
func (e LoadBalancer) RemoveZoneSuffix(name string, suffix []string) string
type ResponsePrinter ¶
type ResponsePrinter struct {
dns.ResponseWriter
}
ResponsePrinter wrap a dns.ResponseWriter and will write example to standard output when WriteMsg is called.
func NewResponsePrinter ¶
func NewResponsePrinter(w dns.ResponseWriter) *ResponsePrinter
NewResponsePrinter returns ResponseWriter.
Source Files