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1 change: 1 addition & 0 deletions _data/tasks.yml
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Expand Up @@ -147,6 +147,7 @@ toc:
section:
- docs/tasks/administer-cluster/calico-network-policy.md
- docs/tasks/administer-cluster/cilium-network-policy.md
- docs/tasks/administer-cluster/kube-router-network-policy.md
- docs/tasks/administer-cluster/romana-network-policy.md
- docs/tasks/administer-cluster/weave-network-policy.md
- docs/tasks/administer-cluster/change-pv-reclaim-policy.md
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159 changes: 120 additions & 39 deletions docs/admin/admission-controllers.md
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Expand Up @@ -19,7 +19,7 @@ API server prior to persistence of the object, but after the request is authenti
and authorized. The plug-in code is in the API server process
and must be compiled into the binary in order to be used at this time.

Each admission control plug-in runs in sequence before a request is accepted into the cluster. If
Each admission control plug-in is run in sequence before a request is accepted into the cluster. If
any of the plug-ins in the sequence reject the request, the entire request is rejected immediately
and an error is returned to the end-user.

Expand Down Expand Up @@ -59,6 +59,28 @@ required.

Rejects all requests. Used for testing.

### DefaultStorageClass

This plug-in observes creation of `PersistentVolumeClaim` objects that do not request any specific storage class
and automatically adds a default storage class to them.
This way, users that do not request any special storage class do not need to care about them at all and they
will get the default one.

This plug-in does not do anything when no default storage class is configured. When more than one storage
class is marked as default, it rejects any creation of `PersistentVolumeClaim` with an error and administrator
must revisit `StorageClass` objects and mark only one as default.
This plugin ignores any `PersistentVolumeClaim` updates; it acts only on creation.

See [persistent volume](/docs/user-guide/persistent-volumes) documentation about persistent volume claims and
storage classes and how to mark a storage class as default.

### DefaultTolerationSeconds

This plug-in sets the default forgiveness toleration for pods to tolerate
the taints `notready:NoExecute` and `unreachable:NoExecute` for 5 minutes,
if the pods don't already have toleration for taints `notready:NoExecute` or
`unreachable:NoExecute`.

### DenyExecOnPrivileged (deprecated)

This plug-in will intercept all requests to exec a command in a pod if that pod has a privileged container.
Expand All @@ -78,6 +100,15 @@ If your cluster supports containers that run with escalated privileges, and you
restrict the ability of end-users to exec commands in those containers, we strongly encourage
enabling this plug-in.

### GenericAdmissionWebhook (alpha)

This plug-in is related to the [Dynamic Admission Control](/docs/admin/extensible-admission-controllers)
introduced in v1.7.
The plug-in calls the webhooks configured via `ExternalAdmissionHookConfiguration`,
and only admits the operation if all the webhooks admit it.
Currently, the plug-in always fails open.
In other words, it ignores the failed calls to a webhook.

### ImagePolicyWebhook

The ImagePolicyWebhook plug-in allows a backend webhook to make admission decisions. You enable this plug-in by setting the admission-control option as follows:
Expand Down Expand Up @@ -190,25 +221,29 @@ Examples of information you might put here are:

In any case, the annotations are provided by the user and are not validated by Kubernetes in any way. In the future, if an annotation is determined to be widely useful, it may be promoted to a named field of ImageReviewSpec.

### ServiceAccount

This plug-in implements automation for [serviceAccounts](/docs/user-guide/service-accounts).
We strongly recommend using this plug-in if you intend to make use of Kubernetes `ServiceAccount` objects.
### Initializers (alpha)

### SecurityContextDeny
This plug-in is introduced in v1.7.
The plug-in determines the initializers of a resource based on the existing
`InitializerConfiguration`s. It sets the pending initializers by modifying the
metadata of the resource to be created.
For more information, please check [Dynamic Admission Control](/docs/admin/extensible-admission-controllers).

This plug-in will deny any pod that attempts to set certain escalating [SecurityContext](/docs/user-guide/security-context) fields. This should be enabled if a cluster doesn't utilize [pod security policies](/docs/user-guide/pod-security-policy) to restrict the set of values a security context can take.
### InitialResources (experimental)

### ResourceQuota
This plug-in observes pod creation requests. If a container omits compute resource requests and limits,
then the plug-in auto-populates a compute resource request based on historical usage of containers running the same image.
If there is not enough data to make a decision the Request is left unchanged.
When the plug-in sets a compute resource request, it does this by *annotating* the
the pod spec rather than mutating the `container.resources` fields.
The annotations added contain the information on what compute resources were auto-populated.

This plug-in will observe the incoming request and ensure that it does not violate any of the constraints
enumerated in the `ResourceQuota` object in a `Namespace`. If you are using `ResourceQuota`
objects in your Kubernetes deployment, you MUST use this plug-in to enforce quota constraints.
See the [InitialResouces proposal](https://git.k8s.io/community/contributors/design-proposals/initial-resources.md) for more details.

See the [resourceQuota design doc](https://git.k8s.io/community/contributors/design-proposals/admission_control_resource_quota.md) and the [example of Resource Quota](/docs/concepts/policy/resource-quotas/) for more details.
### LimitPodHardAntiAffinity

It is strongly encouraged that this plug-in is configured last in the sequence of admission control plug-ins. This is
so that quota is not prematurely incremented only for the request to be rejected later in admission control.
This plug-in denies any pod that defines `AntiAffinity` topology key other than
`kubernetes.io/hostname` in `requiredDuringSchedulingRequiredDuringExecution`.

### LimitRanger

Expand All @@ -220,14 +255,18 @@ applies a 0.1 CPU requirement to all Pods in the `default` namespace.

See the [limitRange design doc](https://git.k8s.io/community/contributors/design-proposals/admission_control_limit_range.md) and the [example of Limit Range](/docs/tasks/configure-pod-container/limit-range/) for more details.

### InitialResources (experimental)
### NamespaceAutoProvision

This plug-in observes pod creation requests. If a container omits compute resource requests and limits,
then the plug-in auto-populates a compute resource request based on historical usage of containers running the same image.
If there is not enough data to make a decision the Request is left unchanged.
When the plug-in sets a compute resource request, it annotates the pod with information on what compute resources it auto-populated.
This plug-in examines all incoming requests on namespaced resources and checks
if the referenced namespace does exist.
It creates a namespace if it cannot be found.
This plug-in is useful in deployments that do not want to restrict creation of
a namespace prior to its usage.

See the [InitialResouces proposal](https://git.k8s.io/community/contributors/design-proposals/initial-resources.md) for more details.
### NamespaceExists

This plug-in checks all requests on namespaced resources other than `Namespace` itself.
If the namespace referenced from a request doesn't exist, the request is rejected.

### NamespaceLifecycle

Expand All @@ -238,25 +277,30 @@ three system reserved namespaces `default`, `kube-system`, `kube-public`.
A `Namespace` deletion kicks off a sequence of operations that remove all objects (pods, services, etc.) in that
namespace. In order to enforce integrity of that process, we strongly recommend running this plug-in.

### DefaultStorageClass
### NodeRestriction

This plug-in observes creation of `PersistentVolumeClaim` objects that do not request any specific storage class
and automatically adds a default storage class to them.
This way, users that do not request any special storage class do no need to care about them at all and they
will get the default one.
This plug-in limits the `Node` and `Pod` objects a kubelet can modify. In order to be limited by this admission plugin,
kubelets must use credentials in the `system:nodes` group, with a username in the form `system:node:<nodeName>`.
Such kubelets will only be allowed to modify their own `Node` API object, and only modify `Pod` API objects that are bound to their node.
Future versions may add additional restrictions to ensure kubelets have the minimal set of permissions required to operate correctly.

This plug-in does not do anything when no default storage class is configured. When more than one storage
class is marked as default, it rejects any creation of `PersistentVolumeClaim` with an error and administrator
must revisit `StorageClass` objects and mark only one as default.
This plugin ignores any `PersistentVolumeClaim` updates, it acts only on creation.
### OwnerReferencesPermissionEnforcement

See [persistent volume](/docs/user-guide/persistent-volumes) documentation about persistent volume claims and
storage classes and how to mark a storage class as default.
This plug-in protects the access to the `metadata.ownerReferences` of an object
so that only users with "delete" permission to the object can change it.
This plug-in also protects the access to `metadata.ownerReferences[x].blockOwnerDeletion`
of an object, so that only users with "update" permission to the `finalizers`
subresource of the referenced *owner* can change it.

### DefaultTolerationSeconds
### PersistentVolumeLabel

This plug-in sets the default forgiveness toleration for pods, which have no forgiveness tolerations, to tolerate
the taints `notready:NoExecute` and `unreachable:NoExecute` for 5 minutes.
This plug-in automatically attaches region or zone labels to PersistentVolumes
as defined by the cloud provider, e.g. GCE and AWS.
It helps ensure the Pods and the PersistentVolumes mounted are in the same
region and/or zone.
If the plug-in doesn't support automatic labelling your PersistentVolumes, you
may need to add the labels manually to prevent pods from mounting volumes from
a different zone.

### PodNodeSelector

Expand Down Expand Up @@ -288,6 +332,12 @@ metadata:
name: namespace3
```

### PodPreset

This plug-in injects a pod with the fields specified in a matching PodPreset.
See also [Inject Information into Pods Using a PodPreset](/docs/tasks/inject-data-application/podpreset)
for more information.

### PodSecurityPolicy

This plug-in acts on creation and modification of the pod and determines if it should be admitted
Expand All @@ -299,12 +349,43 @@ extensions group (`--runtime-config=extensions/v1beta1/podsecuritypolicy=true`).
See also [Pod Security Policy documentation](/docs/concepts/policy/pod-security-policy/)
for more information.

### NodeRestriction
### PodTolerationRestriction

This plug-in limits the `Node` and `Pod` objects a kubelet can modify. In order to be limited by this admission plugin,
kubelets must use credentials in the `system:nodes` group, with a username in the form `system:node:<nodeName>`.
Such kubelets will only be allowed to modify their own `Node` API object, and only modify `Pod` API objects that are bound to their node.
Future versions may add additional restrictions to ensure kubelets have the minimal set of permissions required to operate correctly.
This plug-in first verifies any conflict between a pod's tolerations and its
namespace's tolerations, and rejects the pod request if there is a conflict.
It then merges the namespace's tolerations into the pod's tolerations.
The resulting tolerations are checked against the namespace's whitelist of
tolerations. If the check succeeds, the pod request is admitted otherwise
rejected.

If the pod's namespace does not have any associated default or whitelist of
tolerations, then the cluster-level default or whitelist of tolerations are used
instead if specified.

Tolerations to a namespace are assigned via the
`scheduler.alpha.kubernetes.io/defaultTolerations` and
`scheduler.alpha.kubernetes.io/tolerationsWhitelist`
annotation keys.

### ResourceQuota

This plug-in will observe the incoming request and ensure that it does not violate any of the constraints
enumerated in the `ResourceQuota` object in a `Namespace`. If you are using `ResourceQuota`
objects in your Kubernetes deployment, you MUST use this plug-in to enforce quota constraints.

See the [resourceQuota design doc](https://git.k8s.io/community/contributors/design-proposals/admission_control_resource_quota.md) and the [example of Resource Quota](/docs/concepts/policy/resource-quotas/) for more details.

It is strongly encouraged that this plug-in is configured last in the sequence of admission control plug-ins. This is
so that quota is not prematurely incremented only for the request to be rejected later in admission control.

### SecurityContextDeny

This plug-in will deny any pod that attempts to set certain escalating [SecurityContext](/docs/user-guide/security-context) fields. This should be enabled if a cluster doesn't utilize [pod security policies](/docs/user-guide/pod-security-policy) to restrict the set of values a security context can take.

### ServiceAccount

This plug-in implements automation for [serviceAccounts](/docs/user-guide/service-accounts).
We strongly recommend using this plug-in if you intend to make use of Kubernetes `ServiceAccount` objects.

## Is there a recommended set of plug-ins to use?

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Expand Up @@ -49,7 +49,7 @@ cd contrib/ansible

**Tell ansible about each machine and its role in your cluster**

Get the IP addresses from the master and nodes. Add those to the `~/contrib/ansible/inventory` file on the host running Ansible.
Get the IP addresses from the master and nodes. Add those to the `~/contrib/ansible/inventory/localhost.ini` file on the host running Ansible.

```shell
[masters]
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2 changes: 2 additions & 0 deletions docs/getting-started-guides/rkt/index.md
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Expand Up @@ -19,6 +19,8 @@ This document describes how to run Kubernetes using [rkt](https://github.com/cor

* The [rkt API service](https://coreos.com/rkt/docs/latest/subcommands/api-service.html) must be running on the node.

* You will need [kubelet](/docs/getting-started-guides/scratch/#kubelet) installed on the node, and it's recommended that you run [kube-proxy](/docs/getting-started-guides/scratch/#kube-proxy) on all nodes. This document describes how to set the parameters for kubelet so that it uses rkt as the runtime.

## Pod networking in rktnetes

### Kubernetes CNI networking
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1 change: 1 addition & 0 deletions docs/tasks/administer-cluster/declare-network-policy.md
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Expand Up @@ -13,6 +13,7 @@ You'll need to have a Kubernetes cluster in place, with network policy support.

* [Calico](/docs/tasks/configure-pod-container/calico-network-policy/)
* [Cilium](/docs/tasks/administer-cluster/cilium-network-policy/)
* [Kube-router](/docs/tasks/administer-cluster/kube-router-network-policy/)
* [Romana](/docs/tasks/configure-pod-container/romana-network-policy/)
* [Weave Net](/docs/tasks/configure-pod-container/weave-network-policy/)

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25 changes: 25 additions & 0 deletions docs/tasks/administer-cluster/kube-router-network-policy.md
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@@ -0,0 +1,25 @@
---
approvers:
- murali-reddy
title: Use Kube-router for NetworkPolicy
---

{% capture overview %}
This page shows how to use [Kube-router](https://github.com/cloudnativelabs/kube-router) for NetworkPolicy.
{% endcapture %}

{% capture prerequisites %}
You need to have a Kubernetes cluster running. If you do not already have a cluster, you can create one by using any of the cluster installers like Kops, Bootkube, Kubeadm etc.
{% endcapture %}

{% capture steps %}
## Installing Kube-router addon
The Kube-router Addon comes with a Network Policy Controller that watches Kubernetes API server for any NetworkPolicy and pods updated and configures iptables rules and ipsets to allow or block traffic as directed by the policies. Please follow the [trying Kube-router with cluster installers](https://github.com/cloudnativelabs/kube-router/tree/master/Documentation#try-kube-router-with-cluster-installers) guide to install Kube-router addon.
{% endcapture %}

{% capture whatsnext %}
Once you have installed the Kube-router addon, you can follow the [NetworkPolicy getting started guide](/docs/getting-started-guides/network-policy/walkthrough) to try out Kubernetes NetworkPolicy.
{% endcapture %}

{% include templates/task.md %}

2 changes: 1 addition & 1 deletion docs/tutorials/stateful-application/basic-stateful-set.md
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Expand Up @@ -499,7 +499,7 @@ web-1 gcr.io/google_containers/nginx-slim:0.8
web-2 gcr.io/google_containers/nginx-slim:0.8
{% endraw %}```
`web-0` has had its image updated, but `web-0` and `web-1` still have the original
`web-0` has had its image updated, but `web-1` and `web-2` still have the original
image. Complete the update by deleting the remaining Pods.
```shell
Expand Down

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