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Azure Blob SDK & Azure Cloud Services

Overview​

Microsoft Azure is a cloud computing platform providing compute, storage, networking, security, identity, AI, and DevOps tooling.

Azure Blob Storage is Microsoft's scalable object storage service designed for:

  • File storage
  • Media hosting
  • Backups
  • Logging
  • Data lakes
  • Static websites

Blob Storage Use Cases​

Use CaseExample
File UploadsImages, PDFs, Videos
BackupsSystem snapshots
Static HostingFrontend websites
StreamingVideo delivery
LogsApplication logging
Data LakesBig data analytics

Azure Storage Architecture​

Storage Services​

ServicePurpose
Blob StorageObject/file storage
Queue StorageMessaging
Table StorageNoSQL key-value
File SharesSMB file system

Blob Types​

Blob TypeDescription
Block BlobFiles/images/videos
Append BlobLogging scenarios
Page BlobVirtual disks

Azure Blob Storage Hierarchy​

Installing Azure Blob SDK​

dotnet add package Azure.Storage.Blobs

Authentication Methods​

MethodRecommended For
Connection StringDevelopment
Shared Access Signature (SAS)Temporary access
Managed IdentityProduction
Azure ADEnterprise auth
{
  "AzureStorage": {
    "ConnectionString": "DefaultEndpointsProtocol=https;..."
  }
}

Blob SDK Workflow​

Creating BlobServiceClient​

using Azure.Storage.Blobs;

var client = new BlobServiceClient(connectionString);

Dependency Injection in ASP.NET Core​

builder.Services.AddSingleton(x =>
{
    return new BlobServiceClient(
        builder.Configuration["AzureStorage:ConnectionString"]);
});

Common Operations​

Creating Containers​

var containerClient = client.GetBlobContainerClient("images");
await containerClient.CreateIfNotExistsAsync();

Uploading Files​

var blobClient = containerClient.GetBlobClient("photo.jpg");
await blobClient.UploadAsync(stream);

Downloading Files​

var response = await blobClient.DownloadAsync();
return response.Value.Content;

Deleting Files​

await blobClient.DeleteIfExistsAsync();

Listing Blobs​

await foreach (var blob in containerClient.GetBlobsAsync())
{
    Console.WriteLine(blob.Name);
}

Upload Workflow​

Generating SAS Tokens​

Shared Access Signatures allow temporary secure access.

var sasUri = blobClient.GenerateSasUri(
    BlobSasPermissions.Read,
    DateTimeOffset.UtcNow.AddHours(1));

Blob Metadata & Tags​

await blobClient.SetMetadataAsync(new Dictionary<string, string>
{
    { "UploadedBy", "Admin" }
});

await blobClient.SetTagsAsync(new Dictionary<string, string>
{
    { "Category", "Invoice" }
});

Blob Access Tiers​

TierUsage
HotFrequently accessed
CoolInfrequent access
ArchiveRarely accessed
await blobClient.SetAccessTierAsync(AccessTier.Cool);

Security Best Practices​

FeaturePurpose
Managed IdentityRemove secrets
SAS TokensLimited access
Private EndpointsInternal networking
EncryptionProtect data
RBACFine-grained permissions
using Azure.Identity;

var client = new BlobServiceClient(
    new Uri("https://mystorage.blob.core.windows.net"),
    new DefaultAzureCredential());

Azure RBAC Roles​

RoleAccess
Storage Blob Data ReaderRead
Storage Blob Data ContributorRead/Write
OwnerFull access

Major Azure Cloud Services​

ServicePurpose
App ServiceWeb app hosting
Azure FunctionsServerless
AKSKubernetes
Azure SQLManaged SQL
Cosmos DBNoSQL database
Service BusMessaging
Key VaultSecret management
Application InsightsMonitoring

Azure Cloud Architecture​

Deploy ASP.NET Core to Azure​

az webapp up --name myapp

Deploy workflow:

Azure Functions — Blob Trigger​

public static class BlobTriggerFunction
{
    [FunctionName("BlobTriggerFunction")]
    public static void Run(
        [BlobTrigger("images/{name}")]
        Stream blob)
    {
    }
}

Azure Service Bus​

FeatureDescription
QueuesPoint-to-point
TopicsPublish/subscribe
Dead Letter QueueFailed messages
Retry PoliciesReliability

Azure Key Vault​

builder.Configuration.AddAzureKeyVault(
    new Uri(vaultUrl),
    new DefaultAzureCredential());

Application Insights​

builder.Services.AddApplicationInsightsTelemetry();

Local Development with Azurite​

docker run -p 10000:10000 mcr.microsoft.com/azure-storage/azurite

Dockerizing ASP.NET Core + Azure SDK​

FROM mcr.microsoft.com/dotnet/aspnet:8.0
WORKDIR /app
COPY . .
ENTRYPOINT ["dotnet", "MyApp.dll"]

Performance Optimization​

OptimizationBenefit
Async UploadsScalability
CDNFaster delivery
CompressionLower bandwidth
Access TiersLower cost
Parallel UploadsFaster transfers

Retry Policies​

var options = new BlobClientOptions
{
    Retry =
    {
        MaxRetries = 5
    }
};

Geo-Redundancy Options​

ReplicationDescription
LRSLocal redundancy
ZRSZone redundancy
GRSGeo redundancy
RA-GRSRead-access geo redundancy

Lifecycle Management​

Automatically move blobs to cheaper tiers:

Event-Driven Architecture​

Common Pitfalls​

MistakeProblem
Storing secrets in codeSecurity risk
Using account keys everywherePoor security
Missing retry policiesReliability issues
No lifecycle managementHigh storage cost
Large synchronous uploadsPoor scalability

Azure Blob SDK Cheat Sheet​

TaskCode
Create Clientnew BlobServiceClient()
Get ContainerGetBlobContainerClient()
Upload BlobUploadAsync()
Download BlobDownloadAsync()
Delete BlobDeleteIfExistsAsync()
Generate SASGenerateSasUri()

Interview Questions​

Beginner​

  1. What is Azure Blob Storage?
  2. What is BlobServiceClient?
  3. Difference between containers and blobs?
  4. What are SAS tokens?
  5. What is Managed Identity?

Intermediate​

  1. Explain Azure RBAC.
  2. Difference between Blob Storage tiers?
  3. How would you upload large files?
  4. Explain Azure Functions.
  5. What is Azurite?

Advanced​

  1. How would you secure Azure Blob Storage?
  2. Explain Azure storage replication strategies.
  3. How would you design a scalable upload service?
  4. Explain event-driven architecture using Azure.
  5. How would you optimize Azure storage cost?

Learning Roadmap​