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.