Quarkus Azure Blob Storage Extension

Quarkus Azure Services Extensions are developed and supported by Microsoft as part of their commitment to Open Standard Enterprise Java. For more information, see Jakarta EE on Azure.

Azure Blob Storage is a massively scalable and secure object storage for cloud-native workloads, archives, data lakes, high-performance computing, and machine learning. This extension allows you to store and retrieve blobs from Azure Blob Storage by injecting a com.azure.storage.blob.BlobServiceClient or com.azure.storage.blob.BlobServiceAsyncClient object inside your Quarkus application.

This is a step by step guide on how to use the Quarkus Azure Blob Storage extension. If you’re looking for a complete code sample, you can find it in the Azure Blob Storage sample.

Installation

If you want to use this extension, you need to add the io.quarkiverse.azureservices:quarkus-azure-services extension first to your build file.

For instance, with Maven, add the following dependency to your POM file:

<dependency>
    <groupId>io.quarkiverse.azureservices</groupId>
    <artifactId>quarkus-azure-storage-blob</artifactId>
    <version>1.0.5</version>
</dependency>

How to Use It

Once you have added the extension to your project, follow the next steps, so you can inject com.azure.storage.blob.BlobServiceClient or com.azure.storage.blob.BlobServiceAsyncClient object in your application to store and read blobs.

Setup your Azure Environment

First thing first. For this sample to work, you need to have an Azure account as well as Azure CLI installed. The Azure CLI is available to install in Windows, macOS and Linux environments. Checkout the installation guide. Then, you need an Azure subscription and log into it by using the az login command. You can run az version to find the version and az upgrade to upgrade to the latest version.

Create an Azure resource group with the az group create command. A resource group is a logical container into which Azure resources are deployed and managed.

az group create \
    --name rg-quarkus-azure-storage-blob \
    --location eastus

Create a general-purpose storage account with the following command:

az storage account create \
    --name stquarkusazurestorageblo \
    --resource-group rg-quarkus-azure-storage-blob \
    --location eastus \
    --sku Standard_ZRS \
    --encryption-services blob

If you log into the Azure portal, you can see the resource group and the storage account you created.

Azure Portal showing the Azure storage account

Blobs are always uploaded into a container. You can organize groups of blobs in containers similar to the way you organize your files on your computer in folders. This guide will use the Azure Storage Blob client to create the container if it doesn’t exist. Alternatively, follow instructions in Create a container if you want to create a container before uploading blobs.

Configure the Azure Storage Blob Client

As you can see below in the Configuration Reference section, this extension has several configuration options. But one of them is mandatory, and that is the quarkus.azure.storage.blob.connection-string. To get the connection string, execute the following Azure CLI command:

export QUARKUS_AZURE_STORAGE_BLOB_CONNECTION_STRING=$(az storage account show-connection-string \
    --resource-group rg-quarkus-azure-storage-blob \
    --name stquarkusazurestorageblo \
    --output tsv)
echo "QUARKUS_AZURE_STORAGE_BLOB_CONNECTION_STRING is: ${QUARKUS_AZURE_STORAGE_BLOB_CONNECTION_STRING}"

Notice that you get the connection string and set it to environment variable QUARKUS_AZURE_STORAGE_BLOB_CONNECTION_STRING, instead of setting it to property quarkus.azure.storage.blob.connection-string in the application.properties file.

Although technically both approaches work, using environment variable is recommended and more secure as there’s no risk of committing the connection string to source control.

Inject the Azure Storage Blob Client

Now that your Azure environment is ready and that you have configured the extension, you can inject the com.azure.storage.blob.BlobServiceClient object in your imperative application or inject the com.azure.storage.blob.BlobServiceAsyncClient object in your reactive application, so you can interact with Azure Blob Storage.

Use the BlobServiceClient in an imperative application

The uploadBlob method first creates the container container-quarkus-azure-storage-blob, sets some text to a text file, and then uploads the text to the container. The downloadBlob method downloads the text file from the container and prints the text to the console.

To execute this sample you can run the following cURL commands:

  • curl -X POST localhost:8080/quarkus-azure-storage-blob

  • curl localhost:8080/quarkus-azure-storage-blob

@Path("/quarkus-azure-storage-blob")
@ApplicationScoped
public class StorageBlobResource {

    @Inject
    BlobServiceClient blobServiceClient;

    @POST
    public Response uploadBlob() {
        BlobContainerClient blobContainerClient = blobServiceClient
                .createBlobContainerIfNotExists("container-quarkus-azure-storage-blob");
        BlobClient blobClient = blobContainerClient.getBlobClient("quarkus-azure-storage-blob.txt");
        blobClient.upload(BinaryData.fromString("Hello quarkus-azure-storage-blob at " + LocalDateTime.now()), true);

        return Response.status(CREATED).build();
    }

    @GET
    public String downloadBlob() {
        BlobContainerClient blobContainerClient = blobServiceClient
                .getBlobContainerClient("container-quarkus-azure-storage-blob");
        BlobClient blobClient = blobContainerClient.getBlobClient("quarkus-azure-storage-blob.txt");

        return blobClient.downloadContent().toString();
    }
}

You can go back to the Azure portal and see the container container-quarkus-azure-storage-blob and the blob quarkus-azure-storage-blob.txt that you’ve created.

Azure Portal showing the content of the file uploaded with the BlobServiceClient object

Use the BlobServiceAsyncClient in a reactive application

Similarly, the uploadBlob method first creates the container container-quarkus-azure-storage-blob-async, sets some text to a text file, and then uploads the text to the container. The downloadBlob method downloads the text file from the container and prints the text to the console.

To execute this sample you can run the following cURL commands:

  • curl -X POST localhost:8080/quarkus-azure-storage-blob-async

  • curl localhost:8080/quarkus-azure-storage-blob-async

@Path("/quarkus-azure-storage-blob-async")
@ApplicationScoped
public class StorageBlobAsyncResource {

    @Inject
    BlobServiceAsyncClient blobServiceAsyncClient;

    @POST
    public Uni<Response> uploadBlob() {
        Mono<BlockBlobItem> blockBlobItem = blobServiceAsyncClient
                .createBlobContainerIfNotExists("container-quarkus-azure-storage-blob-async")
                .map(it -> it.getBlobAsyncClient("quarkus-azure-storage-blob-async.txt"))
                .flatMap(it -> it.upload(BinaryData.fromString("Hello quarkus-azure-storage-blob-async at " + LocalDateTime.now()), true));

        return Uni.createFrom().completionStage(blockBlobItem.toFuture()).map(it -> Response.status(CREATED).build());
    }

    @GET
    public Uni<Response> downloadBlob() {
        BlobAsyncClient blobAsyncClient = blobServiceAsyncClient.getBlobContainerAsyncClient("container-quarkus-azure-storage-blob-async")
                .getBlobAsyncClient("quarkus-azure-storage-blob-async.txt");

        return Uni.createFrom()
                .completionStage(blobAsyncClient.downloadContent().map(it -> Response.ok().entity(it.toString()).build())
                        .toFuture());
    }
}

You can also go back to the Azure portal and see the container container-quarkus-azure-storage-blob-async and the blob quarkus-azure-storage-blob-async.txt that you’ve created.

Azure Portal showing the content of the file uploaded with the BlobServiceAsyncClient object

Extension Configuration Reference

Configuration property fixed at build time - All other configuration properties are overridable at runtime

Configuration property

Type

Default

quarkus.azure.storage.blob.health.enabled

Whether a health check is published in case the smallrye-health extension is present.

Environment variable: QUARKUS_AZURE_STORAGE_BLOB_HEALTH_ENABLED

boolean

true

quarkus.azure.storage.blob.devservices.enabled

If DevServices has been explicitly enabled or disabled. DevServices is generally enabled by default, unless there is an existing configuration present.

When DevServices is enabled Quarkus will attempt to automatically configure and start an azurite instance when running in Dev or Test mode and when Docker is running.

Environment variable: QUARKUS_AZURE_STORAGE_BLOB_DEVSERVICES_ENABLED

boolean

true

quarkus.azure.storage.blob.devservices.image-name

The container image name to use, for container based DevServices providers.

Environment variable: QUARKUS_AZURE_STORAGE_BLOB_DEVSERVICES_IMAGE_NAME

string

mcr.microsoft.com/azure-storage/azurite:3.30.0

quarkus.azure.storage.blob.devservices.port

Optional fixed port the Dev services will listen to.

If not defined, the port will be chosen randomly.

Environment variable: QUARKUS_AZURE_STORAGE_BLOB_DEVSERVICES_PORT

int

quarkus.azure.storage.blob.devservices.shared

Indicates if the azurite instance managed by Quarkus Dev Services is shared. When shared, Quarkus looks for running containers using label-based service discovery. If a matching container is found, it is used, and so a second one is not started. Otherwise, Dev Services for Azure Storage Blob starts a new container.

The discovery uses the quarkus-dev-service-azure-storage-blob label. The value is configured using the service-name property.

Container sharing is only used in dev mode.

Environment variable: QUARKUS_AZURE_STORAGE_BLOB_DEVSERVICES_SHARED

boolean

true

quarkus.azure.storage.blob.devservices.service-name

The value of the quarkus-dev-service-azure-storage-blob label attached to the started container. This property is used when shared is set to true. In this case, before starting a container, Dev Services for Azure Storage Blob looks for a container with the quarkus-dev-service-azure-storage-blob label set to the configured value. If found, it will use this container instead of starting a new one. Otherwise it starts a new container with the quarkus-dev-service-azure-storage-blob label set to the specified value.

This property is used when you need multiple shared azurite instances.

Environment variable: QUARKUS_AZURE_STORAGE_BLOB_DEVSERVICES_SERVICE_NAME

string

default-storage-blob

quarkus.azure.storage.blob.enabled

The flag to enable the storage blob. If set to false, the storage blob will be disabled

Environment variable: QUARKUS_AZURE_STORAGE_BLOB_ENABLED

boolean

true

quarkus.azure.storage.blob.connection-string

The connection string of Azure Storage Account. Required if quarkus.azure.storage.blob.enabled is set to true

Environment variable: QUARKUS_AZURE_STORAGE_BLOB_CONNECTION_STRING

string