Azure Blob Storage binding spec

Detailed documentation on the Azure Blob Storage binding component

Component format

To setup Azure Blob Storage binding create a component of type bindings.azure.blobstorage. See this guide on how to create and apply a binding configuration.

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>

Warning

The above example uses secrets as plain strings. It is recommended to use a secret store for the secrets as described here.

Spec metadata fields

Binding support

This component supports output binding with the following operations:

• create : Create blob
• get : 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

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

Examples

Save text to a random generated UUID blob

• Windows
• Linux

On Windows, utilize cmd prompt (PowerShell has different escaping mechanism)

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

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

Save text to a specific blob

• Windows
• Linux

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

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

Save a file to a blob

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

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:

• Windows
• Linux

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

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

Response

The response body will contain the following 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:

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

Example

• Windows
• Linux

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

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

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:

{
    "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
• Bindings building block
• How-To: Trigger application with input binding
• How-To: Use bindings to interface with external resources
• Bindings API reference

Last modified March 18, 2021: Merge pull request #1321 from dapr/aacrawfi/logos (9a399d5)