---
type: docs
title: "Azure Blob Storage binding spec"
linkTitle: "Azure Blob Storage"
description: "Detailed documentation on the Azure Blob Storage binding component"
aliases: 
  - "/operations/components/setup-bindings/supported-bindings/blobstorage/"
---

## Component format

To setup Azure Blob Storage binding create a component of type `bindings.azure.blobstorage`. See [this guide]({{< ref "howto-bindings.md#1-create-a-binding" >}}) on how to create and apply a binding configuration.


```yaml
apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
  namespace: <NAMESPACE>
spec:
  type: bindings.azure.blobstorage
  version: v1
  metadata:
  - name: storageAccount
    value: myStorageAccountName
  - name: storageAccessKey
    value: ***********
  - name: container
    value: container1
  - name: decodeBase64
    value: <bool>
  - name: getBlobRetryCount
    value: <integer>
```
{{% alert title="Warning" color="warning" %}}
The above example uses secrets as plain strings. It is recommended to use a secret store for the secrets as described [here]({{< ref component-secrets.md >}}).
{{% /alert %}}

## Spec metadata fields

| Field              | Required | Binding support | Details | Example |
|--------------------|:--------:|--------|---------|---------|
| storageAccount | Y | Output | The Blob Storage account name | `"myexmapleaccount"` |
| storageAccessKey | Y | Output | The Blob Storage access key | `"access-key"` |
| container | Y | Output | The name of the Blob Storage container to write to | `"myexamplecontainer"` |
| decodeBase64 | N | Output | Configuration to decode base64 file content before saving to Blob Storage. (In case of saving a file with binary content). `"true"` is the only allowed positive value. Other positive variations like `"True"` are not acceptable. Defaults to `"false"` | `"true"`, `"false"` |
| getBlobRetryCount | N | Output | Specifies the maximum number of HTTP GET requests that will be made while reading from a RetryReader Defaults to `"10"` | `"1"`, `"2"` 


## Binding support

This component supports **output binding** with the following operations:

- `create` : [Create blob](#create-blob)
- `get` : [Get blob](#get-blob)

### Create blob

To perform a create blob operation, invoke the Azure Blob Storage binding with a `POST` method and the following JSON body:

> Note: by default, a random UUID is generated. See below for Metadata support to set the name

```json
{
  "operation": "create",
  "data": "YOUR_CONTENT"
}
```

#### Examples


##### Save text to a random generated UUID blob
  
{{< tabs Windows Linux >}}
  {{% codetab %}}
  On Windows, utilize cmd prompt (PowerShell has different escaping mechanism)
  ```bash
  curl -d "{ \"operation\": \"create\", \"data\": \"Hello World\" }" http://localhost:<dapr-port>/v1.0/bindings/<binding-name>
  ```
  {{% /codetab %}}

  {{% codetab %}}
  ```bash
  curl -d '{ "operation": "create", "data": "Hello World" }' \
        http://localhost:<dapr-port>/v1.0/bindings/<binding-name>
  ```
  {{% /codetab %}}

{{< /tabs >}}

##### Save text to a specific blob

{{< tabs Windows Linux >}}

  {{% codetab %}}
  ```bash
  curl -d "{ \"operation\": \"create\", \"data\": \"Hello World\", \"metadata\": { \"blobName\": \"my-test-file.txt\" } }" \
        http://localhost:<dapr-port>/v1.0/bindings/<binding-name>
  ```
  {{% /codetab %}}

  {{% codetab %}}
  ```bash
  curl -d '{ "operation": "create", "data": "Hello World", "metadata": { "blobName": "my-test-file.txt" } }' \
        http://localhost:<dapr-port>/v1.0/bindings/<binding-name>
  ```
  {{% /codetab %}}

{{< /tabs >}}


##### Save a file to a blob

To upload a file, encode it as Base64 and let the Binding know to deserialize it:

```yaml
apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
  namespace: <NAMESPACE>
spec:
  type: bindings.azure.blobstorage
  version: v1
  metadata:
  - name: storageAccount
    value: myStorageAccountName
  - name: storageAccessKey
    value: ***********
  - name: container
    value: container1
  - name: decodeBase64
    value: "true"
```

Then you can upload it as you would normally:

{{< tabs Windows Linux >}}

  {{% codetab %}}
  ```bash
  curl -d "{ \"operation\": \"create\", \"data\": \"YOUR_BASE_64_CONTENT\", \"metadata\": { \"blobName\": \"my-test-file.jpg\" } }" http://localhost:<dapr-port>/v1.0/bindings/<binding-name>
  ```
  {{% /codetab %}}

  {{% codetab %}}
  ```bash
  curl -d '{ "operation": "create", "data": "YOUR_BASE_64_CONTENT", "metadata": { "blobName": "my-test-file.jpg" } }' \
        http://localhost:<dapr-port>/v1.0/bindings/<binding-name>
  ```
  {{% /codetab %}}

{{< /tabs >}}

#### Response

The response body will contain the following JSON:

```json
{
   "blobURL": "https://<your account name>. blob.core.windows.net/<your container name>/<filename>"
}

```

### Get blob

To perform a get blob operation, invoke the Azure Blob Storage binding with a `POST` method and the following JSON body:

```json
{
  "operation": "get",
  "metadata": {
    "blobName": "myblob"
  }
}
```

#### Example

{{< tabs Windows Linux >}}

  {{% codetab %}}
  ```bash
  curl -d '{ \"operation\": \"get\", \"metadata\": { \"blobName\": \"myblob\" }}' http://localhost:<dapr-port>/v1.0/bindings/<binding-name> 
  ```
  {{% /codetab %}}

  {{% codetab %}}
  ```bash
  curl -d '{ "operation": "get", "metadata": { "blobName": "myblob" }}' \
        http://localhost:<dapr-port>/v1.0/bindings/<binding-name> 
  ```
  {{% /codetab %}}

{{< /tabs >}}

#### Response

The response body contains the value stored in the blob object.

## Metadata information

By default the Azure Blob Storage output binding auto generates a UUID as the blob filename and is not assigned any system or custom metadata to it. It is configurable in the metadata property of the message (all optional).

Applications publishing to an Azure Blob Storage output binding should send a message with the following format:

```json
{
    "data": "file content",
    "metadata": {
        "blobName"           : "filename.txt",
        "ContentType"        : "text/plain",
        "ContentMD5"         : "vZGKbMRDAnMs4BIwlXaRvQ==",
        "ContentEncoding"    : "UTF-8",
        "ContentLanguage"    : "en-us",
        "ContentDisposition" : "attachment",
        "CacheControl"       : "no-cache",
        "Custom"             : "hello-world",
    },
    "operation": "create"
}
```

## Related links

- [Basic schema for a Dapr component]({{< ref component-schema >}})
- [Bindings building block]({{< ref bindings >}})
- [How-To: Trigger application with input binding]({{< ref howto-triggers.md >}})
- [How-To: Use bindings to interface with external resources]({{< ref howto-bindings.md >}})
- [Bindings API reference]({{< ref bindings_api.md >}})