StorageOS and OpenShift 3.7 by araustorageos

Install StorageOS

Prepare host

First, ensure all the pre-req kernel modules are enabled by running the following.

./enable-lio.sh

Install StorageOS

(Openshift 3.9 supports feature gates such as mount propagation, but this is not available in Openshift 3.7. As a result, the install of StorageOS in this scenario is done by container install rather than using a DaemonSet)

docker run -d --name storageos \ -e HOSTNAME \ -e ADVERTISE_IP=[[HOST_IP]] \ -e JOIN=[[HOST_IP]] \ --pid=host \ --network=host \ --privileged \ --cap-add SYS_ADMIN \ --device /dev/fuse \ -v /sys:/sys \ -v /var/lib/storageos:/var/lib/storageos:rshared \ -v /run/docker/plugins:/run/docker/plugins \ storageos/node:1.0.0-rc2 server

Create StorageClass

First, create a secret that specifies the StorageOS api endpoint.

APIADDRESS=$(echo -n "tcp://127.0.0.1:5705" | base64); sed -i "s/REPLACE/$APIADDRESS/g" secret.yaml

oc --as system:admin -n default create -f secret.yaml

Create fast StorageClass:

oc --as system:admin create -f storageclass.yaml

Check cluster

Check StorageOS status

The StorageOS CLI presents useful information regarding the cluster and its volumes.

Using StorageOS CLI: storageos cluster health
Check the health REST API endpoint directly by: curl 127.0.0.1:5706/health
If the cluster is not healthy, then wait a few seconds for the cluster to start and run: docker logs storageos

Use StorageOS volumes

Create Persistent Volume Claim

oc create -f pvc.yaml

List volumes: oc get pv,pvc

List volumes with the StorageOS CLI: storageos volume ls

See the status of the volume with the oc cli and verify the volume is successfully allocated.

oc describe pvc

Web UI

StorageOS container spins up a lightweight UI from which you can see and control volumes, nodes, etc.

Render https://[[HOST_SUBDOMAIN]]-5705-[[KATACODA_HOST]].environments.katacoda.com/

Access to StorageOS UI by clicking on the StorageOS tab in the console frame of this browser window. This will open the web console link in another tab or window of your browser.

You should see an StorageOS login window with Username and Password forms.

Username: storageos Password: storageos

Run Pods with PVCs

Test pods

In this section, we create a pod that mounts a PVC and it writes the string Testing StorageOS with Openshift in it. Once the pod is finished, we start a different pod that mounts the same volume and prints the data to STDOUT.

Create a pod that writes to the pvc. oc create -f pod-write.yaml

oc get pods

The pod finishes as soon as the file has been written. Let's check the data in the volume by attaching it to a new pod that will print the written data to STDOUT.

Wait until the write pod finishes and delete afterwards.

until [ "$(oc get pods | grep write | grep -c Completed)" -gt 0 ]; do sleep 1; done

oc delete po write

Create the read pod.

oc create -f pod-read.yaml

Check the output of the read pod coming from the persisted volume.

oc logs read

You can see that the string Testing StorageOS with Openshift has been persisted between executions. Any pods can access the data from any host, as volumes are globally namespaced across the cluster.

Mind that it doesn't matter if the pod read would run in a different host of the pod write as StorageOS takes care of it.

cd <directory>	Change directory
ls	List directory
echo 'contents' > <file>	Write contents to a file
cat <file>	Output contents of file

i	In Command Mode	Change into Insert Mode, you can now insert and edit text in the file
esc	In Insert Mode	Change into Command Mode, you can now execute commands
:wq	In Command Mode	Save and Exit

Welcome!

araustorageos - StorageOS and OpenShift 3.7

Congratulations!

You've completed the scenario!

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