How to use volumes in workflows - Container Compute Service

If the steps in a workflow need to share data or status, you can mount a volume to the workflow. You can mount OSS and NAS volumes to workflows. This topic describes how to mount a statically provisioned volume to a workflow.

Usage notes

OSS volumes and NAS volumes are used in different scenarios. For more information about the usage notes, limits, and billing of different types of volumes, see Storage overview.

Examples

Use OSS volumes

Create an OSS volume based on the following sample code.

For more information, see Mount a statically provisioned OSS volume.

apiVersion: v1
kind: Secret
metadata:
  name: oss-secret
  namespace: argo
stringData:
  akId: <yourAccessKey ID> # Replace with the actual AccessKey ID. 
  akSecret: <yourAccessKey Secret> # Replace with the actual AccessKey secret. 
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-oss
  namespace: argo
  labels:
    alicloud-pvname: pv-oss
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  csi:
    driver: ossplugin.csi.alibabacloud.com
    volumeHandle: pv-oss   # Replace with the actual PV name. 
    nodePublishSecretRef:
      name: oss-secret
      namespace: argo
    volumeAttributes:
      bucket: <your bucket name> # Replace with the actual OSS bucket name. 
      url: "oss-<your region id>-internal.aliyuncs.com" # Replace <your region id> with the region ID of the OSS bucket, such as oss-cn-beijing-internal.aliyuncs.com for China (Beijing). 
      otherOpts: "-o max_stat_cache_size=0 -o allow_other -o multipart_size=30 -o parallel_count=20" # -o max_stat_cache_size=0
      path: "/"  # The root directory of the OSS bucket. You can also specify a subdirectory of the OSS bucket. Example: testdir/testdir1. 
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-oss
  namespace: argo
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 5Gi
  selector:
    matchLabels:
      alicloud-pvname: pv-oss

Optional parameters

You can configure custom parameters in the -o *** -o *** format for the OSS volume. Example: -o umask=022 -o max_stat_cache_size=0 -o allow_other.

Parameter	Description
umask	Modifies the permission mask of files in ossfs. For example, if you specify `umask=022`, the permission mask of files in ossfs changes to 755. By default, the permission mask of files uploaded by using the OSS SDK or the OSS console is 640 in ossfs. Therefore, we recommend that you specify the umask parameter if you want to split reads and writes.
max_stat_cache_size	The maximum number of files whose metadata can be stored in metadata caches. Metadata caching can accelerate List operations. However, if you modify files by using methods other than ossfs, such as the OSS console, OSS SDKs, or ossutil, the cached metadata of the files is not synchronously updated. As a result, the cached metadata becomes outdated, and the results of LIST operations may be inaccurate.
allow_other	Allows other users to access the mounted directory. However, these users cannot access the files in the directory.

For more information about other parameters, see Options.

Use the following sample code to create a workflow to use the OSS volume:

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: volumes-existing-
  namespace: argo
spec:
  entrypoint: volumes-existing-example
  volumes:
  # Pass my-existing-volume as an argument to the volumes-existing-example template.
  # Same syntax as k8s Pod spec.
  - name: workdir
    persistentVolumeClaim:
      claimName: pvc-oss

  templates:
  - name: volumes-existing-example
    steps:
    - - name: generate
        template: whalesay
    - - name: print
        template: print-message

  - name: whalesay
    container:
      image: mirrors-ssl.aliyuncs.com/busybox:latest
      command: [sh, -c]
      args: ["echo generating message in volume; echo hello world | tee /mnt/vol/hello_world.txt"]
      volumeMounts:
      - name: workdir
        mountPath: /mnt/vol

  - name: print-message
    container:
      image: mirrors-ssl.aliyuncs.com/alpine:latest
      command: [sh, -c]
      args: ["echo getting message from volume; find /mnt/vol; cat /mnt/vol/hello_world.txt"]
      volumeMounts:
      - name: workdir
        mountPath: /mnt/vol

Use NAS volumes

Use the following sample code to create a statically provisioned NAS volume:

For more information, see Mount a statically provisioned NAS volume.

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-nas
  namespace: argo
  labels:
    alicloud-pvname: pv-nas
spec:
  capacity:
    storage: 100Gi
  accessModes:
    - ReadWriteMany
  csi:
    driver: nasplugin.csi.alibabacloud.com
    volumeHandle: pv-nas   # Specify the name of the PV. 
    volumeAttributes:
      server: "<your nas filesystem id>.cn-beijing.nas.aliyuncs.com"
      path: "/"
  mountOptions:
  - nolock,tcp,noresvport
  - vers=3
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: pvc-nas
  namespace: argo
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 100Gi
  selector:
    matchLabels:
      alicloud-pvname: pv-nas

Use the following sample code to create a workflow to use the NAS volume.

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: volumes-existing-
  namespace: argo
spec:
  entrypoint: volumes-existing-example
  volumes:
  # Pass my-existing-volume as an argument to the volumes-existing-example template.
  # Same syntax as k8s Pod spec.
  - name: workdir
    persistentVolumeClaim:
      claimName: pvc-nas

  templates:
  - name: volumes-existing-example
    steps:
    - - name: generate
        template: whalesay
    - - name: print
        template: print-message

  - name: whalesay
    container:
      image: mirrors-ssl.aliyuncs.com/busybox:latest
      command: [sh, -c]
      args: ["echo generating message in volume; echo hello world | tee /mnt/vol/hello_world.txt"]
      volumeMounts:
      - name: workdir
        mountPath: /mnt/vol

  - name: print-message
    container:
      image: mirrors-ssl.aliyuncs.com/alpine:latest
      command: [sh, -c]
      args: ["echo getting message from volume; find /mnt/vol; cat /mnt/vol/hello_world.txt"]
      volumeMounts:
      - name: workdir
        mountPath: /mnt/vol