Persist files in Azure Cloud Shell

• 02/24/2020
• 6 minutes to read
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Cloud Shell utilizes Azure File storage to persist files across sessions. On initial start, Cloud Shell prompts you to associate a new or existing file share to persist files across sessions.

Create new storage

When you use basic settings and select only a subscription, Cloud Shell creates three resources on your behalf in the supported region that's nearest to you:

• Resource group: cloud-shell-storage-<region>
• Storage account: cs<uniqueGuid>
• File share: cs-<user>-<domain>-com-<uniqueGuid>

The file share mounts as clouddrive in your $Home directory. This is a one-time action, and the file share mounts automatically in subsequent sessions.

The file share also contains a 5-GB image that is created for you which automatically persists data in your $Home directory. This applies for both Bash and PowerShell.

Use existing resources

By using the advanced option, you can associate existing resources. When selecting a Cloud Shell region you must select a backing storage account co-located in the same region. For example, if your assigned region is West US then you must associate a file share that resides within West US as well.

When the storage setup prompt appears, select Show advanced settings to view additional options. The populated storage options filter for locally redundant storage (LRS), geo-redundant storage (GRS), and zone-redundant storage (ZRS) accounts.

Securing storage access

For security, each user should provision their own storage account. For Azure role-based access control (Azure RBAC), users must have contributor access or above at the storage account level.

Cloud Shell uses an Azure File Share in a storage account, inside a specified subscription. Due to inherited permissions, users with sufficient access rights to the subscription will be able to access all the storage accounts, and file shares contained in the subscription.

Users should lock down access to their files by setting the permissions at the storage account or the subscription level.

Supported storage regions

To find your current region you may run env in Bash and locate the variable ACC_LOCATION, or from PowerShell run $env:ACC_LOCATION. File shares receive a 5-GB image created for you to persist your $Home directory.

Cloud Shell machines exist in the following regions:

Customers should choose a primary region, unless they have a requirement that their data at rest be stored in a particular region. If they have such a requirement, a secondary storage region should be used.

Secondary storage regions

If a secondary storage region is used, the associated Azure storage account resides in a different region as the Cloud Shell machine that you're mounting them to. For example, Jane can set her storage account to be located in Canada East, a secondary region, but the machine she is mounted to is still located in a primary region. Her data at rest is located in Canada, but it is processed in the United States.

A user can run (Get-CloudDrive | Get-AzStorageAccount).Location in PowerShell to see the location of their File Share.

Restrict resource creation with an Azure resource policy

Storage accounts that you create in Cloud Shell are tagged with ms-resource-usage:azure-cloud-shell. If you want to disallow users from creating storage accounts in Cloud Shell, create an Azure resource policy for tags that are triggered by this specific tag.

How Cloud Shell storage works

Cloud Shell persists files through both of the following methods:

• Creating a disk image of your $Home directory to persist all contents within the directory. The disk image is saved in your specified file share as acc_<User>.img at fileshare.storage.windows.net/fileshare/.cloudconsole/acc_<User>.img, and it automatically syncs changes.
• Mounting your specified file share as clouddrive in your $Home directory for direct file-share interaction. /Home/<User>/clouddrive is mapped to fileshare.storage.windows.net/fileshare.

clouddrive commands

Use the clouddrive command

In Cloud Shell, you can run a command called clouddrive, which enables you to manually update the file share that is mounted to Cloud Shell.

List clouddrive

To discover which file share is mounted as clouddrive, run the df command.

The file path to clouddrive shows your storage account name and file share in the URL. For example, //storageaccountname.file.core.windows.net/filesharename

justin@Azure:~$ df
Filesystem                                          1K-blocks   Used  Available Use% Mounted on
overlay                                             29711408 5577940   24117084  19% /
tmpfs                                                 986716       0     986716   0% /dev
tmpfs                                                 986716       0     986716   0% /sys/fs/cgroup
/dev/sda1                                           29711408 5577940   24117084  19% /etc/hosts
shm                                                    65536       0      65536   0% /dev/shm
//mystoragename.file.core.windows.net/fileshareName 5368709120    64 5368709056   1% /home/justin/clouddrive
justin@Azure:~$

Mount a new clouddrive

Prerequisites for manual mounting

You can update the file share that's associated with Cloud Shell by using the clouddrive mount command.

If you mount an existing file share, the storage accounts must be located in your select Cloud Shell region. Retrieve the location by running env and checking the ACC_LOCATION.

The clouddrive mount command

Run the clouddrive mount command with the following parameters:

clouddrive mount -s mySubscription -g myRG -n storageAccountName -f fileShareName

To view more details, run clouddrive mount -h, as shown here:

Unmount clouddrive

You can unmount a file share that's mounted to Cloud Shell at any time. Since Cloud Shell requires a mounted file share to be used, you will be prompted to create and mount another file share on the next session.

1. Run clouddrive unmount.
2. Acknowledge and confirm prompts.

Your file share will continue to exist unless you delete it manually. Cloud Shell will no longer search for this file share on subsequent sessions. To view more details, run clouddrive unmount -h, as shown here:

PowerShell-specific commands

List clouddrive Azure file shares

The Get-CloudDrive cmdlet retrieves the Azure file share information currently mounted by the clouddrive in the Cloud Shell.

Unmount clouddrive

You can unmount an Azure file share that's mounted to Cloud Shell at any time. If the Azure file share has been removed, you will be prompted to create and mount a new Azure file share at the next session.

The Dismount-CloudDrive cmdlet unmounts an Azure file share from the current storage account. Dismounting the clouddrive terminates the current session. The user will be prompted to create and mount a new Azure file share during the next session.

Transfer local files to Cloud Shell

The clouddrive directory syncs with the Azure portal storage blade. Use this blade to transfer local files to or from your file share. Updating files from within Cloud Shell is reflected in the file storage GUI when you refresh the blade.

Download files

1. In the Azure portal, go to the mounted file share.
2. Select the target file.
3. Select the Download button.

Upload files

1. Go to your mounted file share.
2. Select the Upload button.
3. Select the file or files that you want to upload.
4. Confirm the upload.

You should now see the files that are accessible in your clouddrive directory in Cloud Shell.

Note: If you need to define a function in a file and call it from the PowerShell cmdlets, then the dot operator must be included. For example: . .\MyFunctions.ps1

Next steps

Cloud Shell Quickstart
Learn about Microsoft Azure Files storage
Learn about storage tags