Exercise - Manage tiered storage using ASP.NET Core apps

10 minutes

You're now going to test out some sample .NET code to retrieve and modify tier levels for some example Azure Storage blobs. You'll create a new BlobStorage account and set the account to Cool. Then, you'll upload some data and use the app to modify the storage tiers.

Download the code and sample data

In this first step, you'll download source code and sample data to your Cloud Shell storage.

Run the following commands in the Cloud Shell to download source code and sample data to the storageapp folder in your Cloud Shell storage:
```
git clone https://github.com/MicrosoftDocs/mslearn-optimize-blob-storage-costs storageapp
cd storageapp
```

Use the CLI to create a new blob storage account

You'll now create a new BlobStorage account and retrieve the account storage key.

Run the following commands in the Cloud Shell to create a new BlobStorage account set to Cool. Replace <random string> in the following code with a string of letters or numbers:

export RESOURCE_GROUP=<rgn>[sandbox resource group name]</rgn>

export AZURE_STORAGE_ACCOUNT=<random string>storageaccount

az storage account create \
    --resource-group $RESOURCE_GROUP \
    --name $AZURE_STORAGE_ACCOUNT \
    --kind BlobStorage \
    --access-tier Cool

Run the following command in the Cloud Shell to retrieve the storage key for the account and store it in a variable:

export AZURE_STORAGE_KEY=`az storage account keys list -g $RESOURCE_GROUP -n $AZURE_STORAGE_ACCOUNT --query [0].value --output tsv`

Create container and upload data

In this step, you'll create a blob container and three blobs, each containing some sample data.

Run the following command in the Cloud Shell to create a new container:

az storage container create \
    --name blobcontainer \
    --account-name $AZURE_STORAGE_ACCOUNT \
    --account-key $AZURE_STORAGE_KEY

Run the following commands in the Cloud Shell to blobs with sample data:

cd ManageStorageTiers
az storage blob upload --file testdata.txt --container-name blobcontainer --name blob1
az storage blob upload --file testdata.txt --container-name blobcontainer --name blob2
az storage blob upload --file testdata.txt --container-name blobcontainer --name blob3

Set the tier for each blob

In this step, you'll set the access tier for each blob.

Run the following command in the Cloud Shell to set blob1 as Archive:

az storage blob set-tier \
    --container-name blobcontainer \
    --name blob1 \
    --tier Archive

Run the following command in the Cloud Shell to set blob2 as Cool:

az storage blob set-tier \
    --container-name blobcontainer \
    --name blob2 \
    --tier Cool

Run the following command in the Cloud Shell to set blob3 as Hot:

az storage blob set-tier \
    --container-name blobcontainer \
    --name blob3 \
    --tier Hot

Manage storage tiers in code

You're now ready to deploy and test out some code. First, you'll set the environment variables the sample app requires. You'll then build and run the sample app (ignore the warnings about the Microsoft.Azure.KeyVault.Core package).

Run the following commands in the Cloud Shell to store the environment variables the app uses:

export STORAGE_CONNECTION_STRING=`az storage account show-connection-string -g $RESOURCE_GROUP -n $AZURE_STORAGE_ACCOUNT --output tsv`
export CONTAINER_NAME=blobcontainer

Run the following command in the Cloud Shell to build and run the ManageStorageTiers app:
```
cd ManageStorageTiers
dotnet build
dotnet run
```
The ManageStorageTiers app now connects to your blob storage and queries the three blobs named blob1, blob2, and blob3. It then changes the storage tier of all three blobs, and queries each blob's storage tier again to verify the change. The Archive tier won't have changed, due to rehydration latency.

Review the app code

In this final step, you'll take a look at the code used by the ManageStorageTiers app to manage and change access tiers.

In the Cloud Shell, enter code ., then use the editor to open ManageStorageTiers\Program.cs.

This code displays the storage tiers for all of the blobs in a container:

private static async Task DisplayBlobTiers(BlobContainerClient blobContainerClient)
{
    AsyncPageable<BlobItem> blobItems = blobContainerClient.GetBlobsAsync();

    await foreach (var blobItem in blobItems)
    {
        Console.WriteLine($"  Blob name {blobItem.Name}:   Tier {blobItem.Properties.AccessTier}");
    }
}

The following methods work together to update the storage tier for a set of blobs in a container:

private static async Task UpdateBlobTiers(BlobContainerClient blobContainerClient)
{
    AsyncPageable<BlobItem> blobItems = blobContainerClient.GetBlobsAsync();

    await foreach (var blobItem in blobItems)
    {
        string blobName = blobItem.Name;
        AccessTier? currentAccessTier = blobItem.Properties.AccessTier;
        AccessTier newAccessTier = GetNewAccessTier(currentAccessTier);

        Console.WriteLine($"  Blob name: {blobItem.Name}   Current tier: {currentAccessTier}   New tier: {newAccessTier}");

        BlobClient blobClient = blobContainerClient.GetBlobClient(blobItem.Name);
        blobClient.SetAccessTier(newAccessTier);
    }
}

private static AccessTier GetNewAccessTier(AccessTier? accessTier)
{
    if (accessTier == AccessTier.Hot)
        return AccessTier.Cool;
    else if (accessTier == AccessTier.Cool)
        return AccessTier.Archive;
    else
        return AccessTier.Hot;
}