# kube-dns

`kube-dns` schedules DNS Pods and Service on the cluster, other pods in cluster
can use the DNS Service’s IP to resolve DNS names.

* [Administrators guide](http://kubernetes.io/docs/admin/dns/)
* [Code repository](http://www.github.com/kubernetes/dns)

## Manually scale kube-dns Deployment

kube-dns creates only one DNS Pod by default. If
[dns-horizontal-autoscaler](../dns-horizontal-autoscaler/)
is not enabled, you may need to manually scale kube-dns Deployment.

Please use below `kubectl scale` command to scale:
```
kubectl --namespace=kube-system scale deployment kube-dns --replicas=<NUM_YOU_WANT>
```

Do not use `kubectl edit` to modify kube-dns Deployment object if it is
controlled by [Addon Manager](../addon-manager/). Otherwise the modifications
will be clobbered, in addition the replicas count for kube-dns Deployment will
be reset to 1. See [Cluster add-ons README](../README.md) and
[#36411](https://github.com/kubernetes/kubernetes/issues/36411) for reference.

## kube-dns Deployment and Service templates

This directory contains the base UNDERSCORE templates that can be used to
generate the kubedns-controller.yaml.in and kubedns.controller.yaml.in needed in
Salt format.

Due to a varied preference in templating language choices, the transform
Makefile in this directory should be enhanced to generate all required formats
from the base underscore templates.

**N.B.**: When you add a parameter you should also update the various scripts
that supply values for your new parameter.  Here is one way you might find those
scripts:

```
cd kubernetes && git grep 'kubedns-controller.yaml'
```

### Base Template files

These are the authoritative base templates.
Run 'make' to generate the Salt and Sed yaml templates from these.

```
kubedns-controller.yaml.base
kubedns-svc.yaml.base
```

### Generated Salt files

```
kubedns-controller.yaml.in
kubedns-svc.yaml.in
```

### Generated Sed files

```
kubedns-controller.yaml.sed
kubedns-svc.yaml.sed
```

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