kubernetes/examples/volumes/storageos/README.md
2017-06-09 13:19:27 +01:00

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# StorageOS Volume
- [StorageOS](#storageos)
- [Prerequisites](#prerequisites)
- [Examples](#examples)
- [Pre-provisioned Volumes](#pre-provisioned)
- [Pod](#pod)
- [Persistent Volumes](#persistent-volumes)
- [Dynamic Provisioning](#dynamic-provisioning)
- [Storage Class](#storage-class)
- [API Configuration](#api-configuration)
## StorageOS
[StorageOS](https://www.storageos.com) can be used as a storage provider for your Kubernetes cluster. StorageOS runs as a container within your Kubernetes environment, making local storage accessible from any node within the Kubernetes cluster. Data can be replicated to protect against node failure.
At its core, StorageOS provides block storage. You may choose the filesystem type to install to make devices usable from within containers.
## Prerequisites
The StorageOS container must be running on each Kubernetes node that wants to contribute storage or that wants to consume storage. For more information on how you can run StorageOS, consult the [StorageOS documentation](https://docs.storageos.com).
## API Configuration
The StorageOS provider has been pre-configured to use the StorageOS API defaults, and no additional configuration is required for testing. If you have changed the API port, or have removed the default account or changed its password (recommended), you must specify the new settings. This is done using Kubernetes [Secrets](../../../docs/user-guide/secrets/).
API configuration is set by using Kubernetes secrets. The configuration secret supports the following parameters:
* `apiAddress`: The address of the StorageOS API. This is optional and defaults to `tcp://localhost:5705`, which should be correct if the StorageOS container is running using the default settings.
* `apiUsername`: The username to authenticate to the StorageOS API with.
* `apiPassword`: The password to authenticate to the StorageOS API with.
* `apiVersion`: Optional, string value defaulting to `1`. Only set this if requested in StorageOS documentation.
Mutiple credentials can be used by creating different secrets.
For Persistent Volumes, secrets must be created in the Pod namespace. Specify the secret name using the `secretName` parameter when attaching existing volumes in Pods or creating new persistent volumes.
For dynamically provisioned volumes using storage classes, the secret can be created in any namespace. Note that you would want this to be an admin-controlled namespace with restricted access to users. Specify the secret namespace as parameter `adminSecretNamespace` and name as parameter `adminSecretName` in storage classes.
Example spec:
```yaml
apiVersion: v1
kind: Secret
metadata:
name: storageos-secret
type: "kubernetes.io/storageos"
data:
apiAddress: dGNwOi8vMTI3LjAuMC4xOjU3MDU=
apiUsername: c3RvcmFnZW9z
apiPassword: c3RvcmFnZW9z
```
Values for `apiAddress`, `apiUsername` and `apiPassword` can be generated with:
```bash
$ echo -n "tcp://127.0.0.1:5705" | base64
dGNwOi8vMTI3LjAuMC4xOjU3MDU=
```
Create the secret:
```bash
$ kubectl create -f storageos-secret.yaml
secret "storageos-secret" created
```
Verify the secret:
```bash
$ kubectl describe secret storageos-secret
Name: storageos-secret
Namespace: default
Labels: <none>
Annotations: <none>
Type: kubernetes.io/storageos
Data
====
apiAddress: 20 bytes
apiPassword: 8 bytes
apiUsername: 8 bytes
```
## Examples
These examples assume you have a running Kubernetes cluster with the StorageOS container running on each node, and that an API configuration secret called `storageos-secret` has been created in the `default` namespace.
### Pre-provisioned Volumes
#### Pod
Pods can be created that access volumes directly.
1. Create a volume using the StorageOS UI, CLI or API. Consult the [StorageOS documentation](https://docs.storageos.com) for details.
1. Create a pod that refers to the new volume. In this case the volume is named `redis-vol01`.
Example spec:
```yaml
apiVersion: v1
kind: Pod
metadata:
labels:
name: redis
role: master
name: test-storageos-redis
spec:
containers:
- name: master
image: kubernetes/redis:v1
env:
- name: MASTER
value: "true"
ports:
- containerPort: 6379
resources:
limits:
cpu: "0.1"
volumeMounts:
- mountPath: /redis-master-data
name: redis-data
volumes:
- name: redis-data
storageos:
# This volume must already exist within StorageOS
volumeName: redis-vol01
# volumeNamespace is optional, and specifies the volume scope within
# StorageOS. If no namespace is provided, it will use the namespace
# of the pod. Set to `default` or leave blank if you are not using
# namespaces.
#volumeNamespace: test-storageos
# The filesystem type to format the volume with, if required.
fsType: ext4
# The secret name for API credentials
secretName: storageos-secret
```
[Download example](storageos-pod.yaml?raw=true)
Create the pod:
```bash
$ kubectl create -f examples/volumes/storageos/storageos-pod.yaml
```
Verify that the pod is running:
```bash
$ kubectl get pods test-storageos-redis
NAME READY STATUS RESTARTS AGE
test-storageos-redis 1/1 Running 0 30m
```
### Persistent Volumes
1. Create a volume using the StorageOS UI, CLI or API. Consult the [StorageOS documentation](https://docs.storageos.com) for details.
1. Create the persistent volume `redis-vol01`.
Example spec:
```yaml
apiVersion: v1
kind: PersistentVolume
metadata:
name: pv0001
spec:
capacity:
storage: 5Gi
accessModes:
- ReadWriteOnce
persistentVolumeReclaimPolicy: Delete
storageos:
# This volume must already exist within StorageOS
volumeName: pv0001
# volumeNamespace is optional, and specifies the volume scope within
# StorageOS. Set to `default` or leave blank if you are not using
# namespaces.
#volumeNamespace: default
# The filesystem type to create on the volume, if required.
fsType: ext4
# The secret name for API credentials
secretName: storageos-secret
```
[Download example](storageos-pv.yaml?raw=true)
Create the persistent volume:
```bash
$ kubectl create -f examples/volumes/storageos/storageos-pv.yaml
```
Verify that the pv has been created:
```bash
$ kubectl describe pv pv0001
Name: pv0001
Labels: <none>
Annotations: <none>
StorageClass: fast
Status: Available
Claim:
Reclaim Policy: Delete
Access Modes: RWO
Capacity: 5Gi
Message:
Source:
Type: StorageOS (a StorageOS Persistent Disk resource)
VolumeName: pv0001
VolumeNamespace:
FSType: ext4
ReadOnly: false
Events: <none>
```
1. Create persistent volume claim
Example spec:
```yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: pvc0001
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
storageClassName: fast
```
[Download example](storageos-pvc.yaml?raw=true)
Create the persistent volume claim:
```bash
$ kubectl create -f examples/volumes/storageos/storageos-pvc.yaml
```
Verify that the pvc has been created:
```bash
$ kubectl describe pvc pvc0001
Name: pvc0001
Namespace: default
StorageClass: fast
Status: Bound
Volume: pv0001
Labels: <none>
Capacity: 5Gi
Access Modes: RWO
No events.
```
1. Create pod which uses the persistent volume claim
Example spec:
```yaml
apiVersion: v1
kind: Pod
metadata:
labels:
name: redis
role: master
name: test-storageos-redis-pvc
spec:
containers:
- name: master
image: kubernetes/redis:v1
env:
- name: MASTER
value: "true"
ports:
- containerPort: 6379
resources:
limits:
cpu: "0.1"
volumeMounts:
- mountPath: /redis-master-data
name: redis-data
volumes:
- name: redis-data
persistentVolumeClaim:
claimName: pvc0001
```
[Download example](storageos-pvcpod.yaml?raw=true)
Create the pod:
```bash
$ kubectl create -f examples/volumes/storageos/storageos-pvcpod.yaml
```
Verify that the pod has been created:
```bash
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
test-storageos-redis-pvc 1/1 Running 0 40s
```
### Dynamic Provisioning
Dynamic provisioning can be used to auto-create volumes when needed. They require a Storage Class, a Persistent Volume Claim, and a Pod.
#### Storage Class
Kubernetes administrators can use storage classes to define different types of storage made available within the cluster. Each storage class definition specifies a provisioner type and any parameters needed to access it, as well as any other configuration.
StorageOS supports the following storage class parameters:
* `pool`: The name of the StorageOS distributed capacity pool to provision the volume from. Uses the `default` pool which is normally present if not specified.
* `description`: The description to assign to volumes that were created dynamically. All volume descriptions will be the same for the storage class, but different storage classes can be used to allow descriptions for different use cases. Defaults to `Kubernetes volume`.
* `fsType`: The default filesystem type to request. Note that user-defined rules within StorageOS may override this value. Defaults to `ext4`.
* `adminSecretNamespace`: The namespace where the API configuration secret is located. Required if adminSecretName set.
* `adminSecretName`: The name of the secret to use for obtaining the StorageOS API credentials. If not specified, default values will be attempted.
1. Create storage class
Example spec:
```yaml
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
name: sc-fast
provisioner: kubernetes.io/storageos
parameters:
pool: default
description: Kubernetes volume
fsType: ext4
adminSecretNamespace: default
adminSecretName: storageos-secret
```
[Download example](storageos-sc.yaml?raw=true)
Create the storage class:
```bash
$ kubectl create -f examples/volumes/storageos/storageos-sc.yaml
```
Verify the storage class has been created:
```bash
$ kubectl describe storageclass fast
Name: fast
IsDefaultClass: No
Annotations: <none>
Provisioner: kubernetes.io/storageos
Parameters: description=Kubernetes volume,fsType=ext4,pool=default,secretName=storageos-secret
No events.
```
1. Create persistent volume claim
Example spec:
```yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: fast0001
spec:
storageClassName: fast
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
```
Create the persistent volume claim (pvc):
```bash
$ kubectl create -f examples/volumes/storageos/storageos-sc-pvc.yaml
```
Verify the pvc has been created:
```bash
$ kubectl describe pvc fast0001
Name: fast0001
Namespace: default
StorageClass: fast
Status: Bound
Volume: pvc-480952e7-f8e0-11e6-af8c-08002736b526
Labels: <none>
Capacity: 5Gi
Access Modes: RWO
Events:
<snip>
```
A new persistent volume will also be created and bound to the pvc:
```bash
$ kubectl describe pv pvc-480952e7-f8e0-11e6-af8c-08002736b526
Name: pvc-480952e7-f8e0-11e6-af8c-08002736b526
Labels: storageos.driver=filesystem
StorageClass: fast
Status: Bound
Claim: default/fast0001
Reclaim Policy: Delete
Access Modes: RWO
Capacity: 5Gi
Message:
Source:
Type: StorageOS (a StorageOS Persistent Disk resource)
VolumeName: pvc-480952e7-f8e0-11e6-af8c-08002736b526
Namespace: default
FSType: ext4
ReadOnly: false
No events.
```
1. Create pod which uses the persistent volume claim
Example spec:
```yaml
apiVersion: v1
kind: Pod
metadata:
labels:
name: redis
role: master
name: test-storageos-redis-sc-pvc
spec:
containers:
- name: master
image: kubernetes/redis:v1
env:
- name: MASTER
value: "true"
ports:
- containerPort: 6379
resources:
limits:
cpu: "0.1"
volumeMounts:
- mountPath: /redis-master-data
name: redis-data
volumes:
- name: redis-data
persistentVolumeClaim:
claimName: fast0001
```
[Download example](storageos-sc-pvcpod.yaml?raw=true)
Create the pod:
```bash
$ kubectl create -f examples/volumes/storageos/storageos-sc-pvcpod.yaml
```
Verify that the pod has been created:
```bash
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
test-storageos-redis-sc-pvc 1/1 Running 0 44s
```
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