Fixed typo in LetsEncrypt example

Removed duplicate Datanet entry from main index.rst

Reworked Use Kubernetes CPU Manager Static Policy prerequisite block.

Restored fault/index version of FM toctree in top-level index.

Added merged doc entries to top level index.rst.

Incorporated review comments. Also some generic formatting clean-up such as
converting abbreviations to rST-style :abbr: markup.

Moved url with embedded substitution out of code-block.

Addressed patch 2 review comments. Some addtional rST tidying. See comment replies
for open questions/issues.

This patch fixes an issue with 'stx' in filenames that may differ downstream using-an-image-from-the-local-docker-registry-in-a-container-spec
new substitution and changing code-blocks to parsed-literals as required.

Initial submission for review. Note that a couple of references to WR persist
in examples. These will be marked up with comments in the review.

Signed-off-by: Stone <ronald.stone@windriver.com>
Change-Id: I1efef569842caff5def9dc00395b594d91d7a5d0
Signed-off-by: Stone <ronald.stone@windriver.com>

2020-12-02 10:34:53 -05:00

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Mount Persistent Volumes in Containers

You can launch, attach, and terminate a busybox container to mount PVCs (Persistent Volume Claims) in your cluster.

This example shows how a volume is claimed and mounted by a simple running container. It is the responsibility of an individual micro-service within an application to make a volume claim, mount it, and use it. For example, the stx-openstack application will make volume claims for mariadb and rabbitmq via their helm charts to orchestrate this.

You must have created the persistent volume claims.

Create the busybox container with the persistent volumes created from the PVCs mounted.

Create a yaml file definition for the busybox container.

% cat <<EOF > busybox.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: busybox
  namespace: default
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  selector:
    matchLabels:
      run: busybox
  template:
    metadata:
      labels:
        run: busybox
    spec:
      containers:
      - args:
        - sh
        image: busybox
        imagePullPolicy: Always
        name: busybox
        stdin: true
        tty: true
        volumeMounts:
        - name: pvc1
          mountPath: "/mnt1"
        - name: pvc2
          mountPath: "/mnt2"
      restartPolicy: Always
      volumes:
      - name: pvc1
        persistentVolumeClaim:
          claimName: test-claim1
      - name: pvc2
        persistentVolumeClaim:
          claimName: test-claim2
EOF

Apply the busybox configuration.
```
% kubectl apply -f busybox.yaml
```

Attach to the busybox and create files on the persistent volumes.

List the available pods.

% kubectl get pods
NAME                       READY   STATUS    RESTARTS   AGE
busybox-5c4f877455-gkg2s   1/1     Running   0          19s

Connect to the pod shell for CLI access.

% kubectl attach busybox-5c4f877455-gkg2s -c busybox -i -t

From the container's console, list the disks to verify that the persistent volumes are attached.

# df
Filesystem           1K-blocks      Used Available Use% Mounted on
overlay               31441920   3239984  28201936  10% /
tmpfs                    65536         0     65536   0% /dev
tmpfs                 65900776         0  65900776   0% /sys/fs/cgroup
/dev/rbd0               999320      2564    980372   0% /mnt1
/dev/rbd1               999320      2564    980372   0% /mnt2
/dev/sda4             20027216   4952208  14034624  26%
...

The PVCs are mounted as /mnt1 and /mnt2.

Create files in the mounted volumes.

# cd /mnt1
# touch i-was-here
# ls /mnt1
i-was-here lost+found
#
# cd /mnt2
# touch i-was-here-too
# ls /mnt2
i-was-here-too lost+found

End the container session.

# exit
Session ended, resume using 'kubectl attach busybox-5c4f877455-gkg2s -c busybox -i -t' command when the pod is running

Terminate the busybox container.
```
% kubectl delete -f busybox.yaml
```

Re-create the busybox container, again attached to persistent volumes.

Apply the busybox configuration.
```
% kubectl apply -f busybox.yaml
```

List the available pods.

% kubectl get pods
NAME                       READY   STATUS    RESTARTS   AGE
busybox-5c4f877455-jgcc4   1/1     Running   0          19s

Connect to the pod shell for CLI access.

% kubectl attach busybox-5c4f877455-jgcc4 -c busybox -i -t

From the container's console, list the disks to verify that the PVCs are attached.

# df
Filesystem           1K-blocks      Used Available Use% Mounted on
overlay               31441920   3239984  28201936  10% /
tmpfs                    65536         0     65536   0% /dev
tmpfs                 65900776         0  65900776   0% /sys/fs/cgroup
/dev/rbd0               999320      2564    980372   0% /mnt1
/dev/rbd1               999320      2564    980372   0% /mnt2
/dev/sda4             20027216   4952208  14034624  26%
...

Verify that the files created during the earlier container session still exist.
```
# ls /mnt1
i-was-here lost+found
# ls /mnt2
i-was-here-too lost+found
```

5.8 KiB Raw Blame History

Mount Persistent Volumes in Containers

5.8 KiB

Raw Blame History