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>

Spec metadata fields

FieldRequiredBinding supportDetailsExample
storageAccountYOutputThe Blob Storage account name"myexmapleaccount"
storageAccessKeyYOutputThe Blob Storage access key"access-key"
containerYOutputThe name of the Blob Storage container to write to"myexamplecontainer"
decodeBase64NOutputConfiguration 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"
getBlobRetryCountNOutputSpecifies 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 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

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

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:


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


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.

Delete blob

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

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

Examples

Delete blob

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


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

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


curl -d '{ "operation": "delete", "metadata": { "blobName": "myblob", "DeleteSnapshotOptions": "only" }}' \
      http://localhost:<dapr-port>/v1.0/bindings/<binding-name>
Delete blob including snapshots

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


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

Response

An HTTP 204 (No Content) and empty body will be retuned if successful.

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"
}
Last modified May 22, 2021: docs: clean up white noise (#1491) (fe1ab8eb)