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cleanup page in configure-pod-container
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Zhuzhenghao committed Feb 26, 2023
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57 changes: 27 additions & 30 deletions ...nt/en/docs/tasks/configure-pod-container/configure-persistent-volume-storage.md
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Expand Up @@ -12,27 +12,24 @@ for storage.
Here is a summary of the process:

1. You, as cluster administrator, create a PersistentVolume backed by physical
storage. You do not associate the volume with any Pod.
storage. You do not associate the volume with any Pod.

1. You, now taking the role of a developer / cluster user, create a
PersistentVolumeClaim that is automatically bound to a suitable
PersistentVolume.
PersistentVolumeClaim that is automatically bound to a suitable
PersistentVolume.

1. You create a Pod that uses the above PersistentVolumeClaim for storage.



## {{% heading "prerequisites" %}}


* You need to have a Kubernetes cluster that has only one Node, and the
{{< glossary_tooltip text="kubectl" term_id="kubectl" >}}
command-line tool must be configured to communicate with your cluster. If you
do not already have a single-node cluster, you can create one by using
[Minikube](https://minikube.sigs.k8s.io/docs/).
{{< glossary_tooltip text="kubectl" term_id="kubectl" >}}
command-line tool must be configured to communicate with your cluster. If you
do not already have a single-node cluster, you can create one by using
[Minikube](https://minikube.sigs.k8s.io/docs/).

* Familiarize yourself with the material in
[Persistent Volumes](/docs/concepts/storage/persistent-volumes/).
[Persistent Volumes](/docs/concepts/storage/persistent-volumes/).

<!-- steps -->

Expand All @@ -50,7 +47,6 @@ In your shell on that Node, create a `/mnt/data` directory:
sudo mkdir /mnt/data
```


In the `/mnt/data` directory, create an `index.html` file:

```shell
Expand Down Expand Up @@ -116,8 +112,10 @@ kubectl get pv task-pv-volume
The output shows that the PersistentVolume has a `STATUS` of `Available`. This
means it has not yet been bound to a PersistentVolumeClaim.

NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM STORAGECLASS REASON AGE
task-pv-volume 10Gi RWO Retain Available manual 4s
```
NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM STORAGECLASS REASON AGE
task-pv-volume 10Gi RWO Retain Available manual 4s
```

## Create a PersistentVolumeClaim

Expand All @@ -132,7 +130,9 @@ Here is the configuration file for the PersistentVolumeClaim:

Create the PersistentVolumeClaim:

kubectl apply -f https://k8s.io/examples/pods/storage/pv-claim.yaml
```shell
kubectl apply -f https://k8s.io/examples/pods/storage/pv-claim.yaml
```

After you create the PersistentVolumeClaim, the Kubernetes control plane looks
for a PersistentVolume that satisfies the claim's requirements. If the control
Expand All @@ -147,8 +147,10 @@ kubectl get pv task-pv-volume

Now the output shows a `STATUS` of `Bound`.

NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM STORAGECLASS REASON AGE
task-pv-volume 10Gi RWO Retain Bound default/task-pv-claim manual 2m
```
NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM STORAGECLASS REASON AGE
task-pv-volume 10Gi RWO Retain Bound default/task-pv-claim manual 2m
```

Look at the PersistentVolumeClaim:

Expand All @@ -159,8 +161,10 @@ kubectl get pvc task-pv-claim
The output shows that the PersistentVolumeClaim is bound to your PersistentVolume,
`task-pv-volume`.

NAME STATUS VOLUME CAPACITY ACCESSMODES STORAGECLASS AGE
task-pv-claim Bound task-pv-volume 10Gi RWO manual 30s
```
NAME STATUS VOLUME CAPACITY ACCESSMODES STORAGECLASS AGE
task-pv-claim Bound task-pv-volume 10Gi RWO manual 30s
```

## Create a Pod

Expand Down Expand Up @@ -206,15 +210,16 @@ curl http://localhost/
The output shows the text that you wrote to the `index.html` file on the
hostPath volume:

Hello from Kubernetes storage

```
Hello from Kubernetes storage
```

If you see that message, you have successfully configured a Pod to
use storage from a PersistentVolumeClaim.

## Clean up

Delete the Pod, the PersistentVolumeClaim and the PersistentVolume:
Delete the Pod, the PersistentVolumeClaim and the PersistentVolume:

```shell
kubectl delete pod task-pv-pod
Expand Down Expand Up @@ -275,12 +280,8 @@ When a Pod consumes a PersistentVolume, the GIDs associated with the
PersistentVolume are not present on the Pod resource itself.
{{< /note >}}
## {{% heading "whatsnext" %}}
* Learn more about [PersistentVolumes](/docs/concepts/storage/persistent-volumes/).
* Read the [Persistent Storage design document](https://git.k8s.io/design-proposals-archive/storage/persistent-storage.md).
Expand All @@ -290,7 +291,3 @@ PersistentVolume are not present on the Pod resource itself.
* [PersistentVolumeSpec](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#persistentvolumespec-v1-core)
* [PersistentVolumeClaim](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#persistentvolumeclaim-v1-core)
* [PersistentVolumeClaimSpec](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#persistentvolumeclaimspec-v1-core)
37 changes: 18 additions & 19 deletions content/en/docs/tasks/configure-pod-container/configure-pod-configmap.md
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Expand Up @@ -15,7 +15,8 @@ ConfigMaps are a Kubernetes mechanism that let you inject configuration data int

The ConfigMap concept allow you to decouple configuration artifacts from image content to
keep containerized applications portable. For example, you can download and run the same
{{< glossary_tooltip text="container image" term_id="image" >}} to spin up containers for the purposes of local development, system test, or running a live end-user workload.
{{< glossary_tooltip text="container image" term_id="image" >}} to spin up containers for
the purposes of local development, system test, or running a live end-user workload.

This page provides a series of usage examples demonstrating how to create ConfigMaps and
configure Pods using data stored in ConfigMaps.
Expand All @@ -30,7 +31,6 @@ step that downloads example data.

<!-- steps -->


## Create a ConfigMap

You can use either `kubectl create configmap` or a ConfigMap generator in `kustomization.yaml`
Expand Down Expand Up @@ -66,15 +66,15 @@ whose filename is a valid key in the directory and packages each of those files
ConfigMap. Any directory entries except regular files are ignored (for example: subdirectories,
symlinks, devices, pipes, and more).


{{< note >}}
Each filename being used for ConfigMap creation must consist of only acceptable characters, which are: letters (`A` to `Z` and `a` to z`), digits (`0` to `9`), '-', '_', or '.'.
If you use `kubectl create configmap` with a directory where any of the file names contains an unacceptable character, the `kubectl` command may fail.
Each filename being used for ConfigMap creation must consist of only acceptable characters,
which are: letters (`A` to `Z` and `a` to z`), digits (`0` to `9`), '-', '_', or '.'.
If you use `kubectl create configmap` with a directory where any of the file names contains
an unacceptable character, the `kubectl` command may fail.

The `kubectl` command does not print an error when it encounters an invalid filename.
{{< /note >}}


Create the local directory:

```shell
Expand Down Expand Up @@ -396,7 +396,6 @@ data:
special.type: charm
```


### Create a ConfigMap from generator

You can also create a ConfigMap from generators and then apply it to create the object
Expand Down Expand Up @@ -543,7 +542,8 @@ section, and learn how to use these objects with Pods.
kubectl create configmap special-config --from-literal=special.how=very
```
2. Assign the `special.how` value defined in the ConfigMap to the `SPECIAL_LEVEL_KEY` environment variable in the Pod specification.
2. Assign the `special.how` value defined in the ConfigMap to the `SPECIAL_LEVEL_KEY`
environment variable in the Pod specification.
{{< codenew file="pods/pod-single-configmap-env-variable.yaml" >}}
Expand Down Expand Up @@ -597,7 +597,6 @@ Here is the manifest you will use:
kubectl create -f https://kubernetes.io/examples/configmap/configmap-multikeys.yaml
```


* Use `envFrom` to define all of the ConfigMap's data as container environment variables. The
key from the ConfigMap becomes the environment variable name in the Pod.
Expand Down Expand Up @@ -627,7 +626,6 @@ For example, the following Pod manifest:
Create that Pod, by running:
```shell
kubectl create -f https://kubernetes.io/examples/pods/pod-configmap-env-var-valueFrom.yaml
```
Expand All @@ -646,7 +644,7 @@ kubectl delete pod dapi-test-pod --now
## Add ConfigMap data to a Volume

As explained in [Create ConfigMaps from files](#create-configmaps-from-files), when you create
a ConfigMap using ``--from-file``, the filename becomes a key stored in the `data` section of
a ConfigMap using `--from-file`, the filename becomes a key stored in the `data` section of
the ConfigMap. The file contents become the key's value.
The examples in this section refer to a ConfigMap named `special-config`:
Expand Down Expand Up @@ -682,7 +680,8 @@ SPECIAL_TYPE
```
Text data is exposed as files using the UTF-8 character encoding. To use some other
character encoding, use `binaryData` (see [ConfigMap object](/docs/concepts/configuration/configmap/#configmap-object) for more details).
character encoding, use `binaryData`
(see [ConfigMap object](/docs/concepts/configuration/configmap/#configmap-object) for more details).
{{< note >}}
If there are any files in the `/etc/config` directory of that container image, the volume
Expand Down Expand Up @@ -722,7 +721,6 @@ Delete that Pod:
kubectl delete pod dapi-test-pod --now
```


### Project keys to specific paths and file permissions

You can project keys to specific paths and specific permissions on a per-file
Expand All @@ -732,7 +730,7 @@ guide explains the syntax.

### Optional references

A ConfigMap reference may be marked _optional_. If the ConfigMap is non-existent, the mounted
A ConfigMap reference may be marked _optional_. If the ConfigMap is non-existent, the mounted
volume will be empty. If the ConfigMap exists, but the referenced key is non-existent, the path
will be absent beneath the mount point. See [Optional ConfigMaps](#optional-configmaps) for more
details.
Expand All @@ -751,7 +749,8 @@ minute by default) + TTL of ConfigMaps cache (1 minute by default) in kubelet. Y
can trigger an immediate refresh by updating one of the pod's annotations.
{{< note >}}
A container using a ConfigMap as a [subPath](/docs/concepts/storage/volumes/#using-subpath) volume will not receive ConfigMap updates.
A container using a ConfigMap as a [subPath](/docs/concepts/storage/volumes/#using-subpath)
volume will not receive ConfigMap updates.
{{< /note >}}
<!-- discussion -->
Expand Down Expand Up @@ -821,7 +820,7 @@ spec:
containers:
- name: test-container
image: gcr.io/google_containers/busybox
command: [ "/bin/sh", "-c", "env" ]
command: ["/bin/sh", "-c", "env"]
env:
- name: SPECIAL_LEVEL_KEY
valueFrom:
Expand Down Expand Up @@ -850,7 +849,7 @@ spec:
containers:
- name: test-container
image: gcr.io/google_containers/busybox
command: [ "/bin/sh", "-c", "ls /etc/config" ]
command: ["/bin/sh", "-c", "ls /etc/config"]
volumeMounts:
- name: config-volume
mountPath: /etc/config
Expand All @@ -875,7 +874,8 @@ are projected to the pod can be as long as kubelet sync period (1 minute by defa
ConfigMaps cache (1 minute by default) in kubelet.

{{< note >}}
A container using a ConfigMap as a [subPath](/docs/concepts/storage/volumes/#using-subpath) volume will not receive ConfigMap updates.
A container using a ConfigMap as a [subPath](/docs/concepts/storage/volumes/#using-subpath)
volume will not receive ConfigMap updates.
{{< /note >}}

## Restrictions
Expand Down Expand Up @@ -926,7 +926,6 @@ kubectl delete configmap -l 'game-config in (config-4,config-5)’
If you created a directory `configure-pod-container` and no longer need it, you should remove that too,
or move it into the trash can / deleted files location.
## {{% heading "whatsnext" %}}
* Follow a real world example of
Expand Down
60 changes: 32 additions & 28 deletions content/en/docs/tasks/configure-pod-container/configure-pod-initialization.md
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Expand Up @@ -5,18 +5,14 @@ weight: 170
---

<!-- overview -->

This page shows how to use an Init Container to initialize a Pod before an
application Container runs.



## {{% heading "prerequisites" %}}


{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}



<!-- steps -->

## Create a Pod that has an Init Container
Expand All @@ -37,55 +33,63 @@ shared Volume at `/work-dir`, and the application container mounts the shared
Volume at `/usr/share/nginx/html`. The init container runs the following command
and then terminates:

wget -O /work-dir/index.html http://info.cern.ch
```shell
wget -O /work-dir/index.html http://info.cern.ch
```

Notice that the init container writes the `index.html` file in the root directory
of the nginx server.

Create the Pod:

kubectl apply -f https://k8s.io/examples/pods/init-containers.yaml
```shell
kubectl apply -f https://k8s.io/examples/pods/init-containers.yaml
```

Verify that the nginx container is running:

kubectl get pod init-demo
```shell
kubectl get pod init-demo
```

The output shows that the nginx container is running:

NAME READY STATUS RESTARTS AGE
init-demo 1/1 Running 0 1m
```
NAME READY STATUS RESTARTS AGE
init-demo 1/1 Running 0 1m
```

Get a shell into the nginx container running in the init-demo Pod:

kubectl exec -it init-demo -- /bin/bash
```shell
kubectl exec -it init-demo -- /bin/bash
```

In your shell, send a GET request to the nginx server:

root@nginx:~# apt-get update
root@nginx:~# apt-get install curl
root@nginx:~# curl localhost
```
root@nginx:~# apt-get update
root@nginx:~# apt-get install curl
root@nginx:~# curl localhost
```

The output shows that nginx is serving the web page that was written by the init container:

<html><head></head><body><header>
<title>http://info.cern.ch</title>
</header>

<h1>http://info.cern.ch - home of the first website</h1>
...
<li><a href="http://info.cern.ch/hypertext/WWW/TheProject.html">Browse the first website</a></li>
...

```html
<html><head></head><body><header>
<title>http://info.cern.ch</title>
</header>

<h1>http://info.cern.ch - home of the first website</h1>
...
<li><a href="http://info.cern.ch/hypertext/WWW/TheProject.html">Browse the first website</a></li>
...
```

## {{% heading "whatsnext" %}}


* Learn more about
[communicating between Containers running in the same Pod](/docs/tasks/access-application-cluster/communicate-containers-same-pod-shared-volume/).
[communicating between Containers running in the same Pod](/docs/tasks/access-application-cluster/communicate-containers-same-pod-shared-volume/).
* Learn more about [Init Containers](/docs/concepts/workloads/pods/init-containers/).
* Learn more about [Volumes](/docs/concepts/storage/volumes/).
* Learn more about [Debugging Init Containers](/docs/tasks/debug/debug-application/debug-init-containers/)



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