Azure blob storage connector

Upload documents to and download documents from Azure Blob Storage in your BPMN process.

About this connector

The Azure Blob Storage connector is an outbound connector that allows you to interact with Azure Blob Storage resources from your BPMN processes.

The connector currently supports uploading and downloading documents.

Prerequisites

To begin using the Azure Blob Storage connector, ensure you have created the following resources:

• An Azure storage account
• An Azure container

Use this connector

New to using an outbound connector? Learn how to add and use this type of connector, apply element templates, use connector secrets, handle results and errors, and more.

Use an outbound connector

Configuration

Authentication

Select an authentication type from the Type dropdown.

Create a new connector secret

Keep your secrets secure by avoiding direct inclusion in the BPMN xml file. Instead, create a secret:

1. Follow our guide for creating secrets.
2. Name your secrets (for example, AZURE_SAS_TOKEN) so you can reference them later in the connector configuration.

OAuth 2.0

Select OAuth 2.0 (Microsoft Entra ID) to authenticate with a Microsoft Entra ID app registration.

1. In the Azure Portal, open Microsoft Entra ID and select + Add > App registration to create a new app registration.
   • Note the client ID and tenant ID from the app registration’s Overview tab.
2. Go to Manage > Certificates & secrets, select + New client secret, and copy the Value (this is your client secret).
3. In Blob Storage, open your container, select Access control (IAM) > Add > Add role assignment, and assign the app registration one of the following roles:
   • Storage Blob Data Contributor
   • Storage Blob Data Reader
4. In the connector configuration, enter the details from the following table.

Property	Type	Required	Description	Example
Tenant id	String	Yes	ID of the Microsoft Entra ID tenant that owns the application.
Client id	String	Yes	Application (client) ID of the registered Microsoft Entra ID application.
Client secret	String	Yes	Client secret generated for the registered Microsoft Entra ID application.
Account url	String	Yes	URL of the Azure Blob Storage account to connect to. Replace <storage_account_name> with your storage account name.	https://<storage_account_name>.blob.core.windows.net/

SAS token

Select SAS token to authenticate with a shared access signature (SAS).

1. In the Azure Portal, open your Storage account > Containers, and select your container.
2. From the container’s toolbar, click Generate SAS.
3. In the connector configuration, enter the SAS token and SAS URL.

Property	Type	Required	Description	Example
SAS token	String	Yes	Shared access signature (SAS) token of the container.
SAS URL	String	Yes	Shared access signature (SAS) URL of the container.

Operations

Select the desired operation from the Operation dropdown.

Upload document

Upload a document to a container. Select Upload blob in the Operation dropdown.

Input parameters

Property	Type	Required	Description	Example
Blob Storage container	String	Yes	Name of the container that organizes a set of blobs. It must match the container the SAS token was created for.
Document source	Dropdown	Yes	Where the document comes from: Camunda Document, Inline Content, or From URL. Defaults to Camunda Document. See document sources.
Camunda document	String	Yes	Reference to a Camunda document. Shown if Document source is Camunda Document.
Content	String	Yes	Content of the document, built from process data. Shown if Document source is Inline Content.
File name	String	No	Name of the document. Shown if Document source is Inline Content.
Content type	String	No	Content type of the document. Shown if Document source is Inline Content.
URL	String	Yes	URL of the document to upload. Shown if Document source is From URL.
File name	String	No	Name of the document. Shown if Document source is From URL.
Document file name	String	No	Name of the blob in the container. By default, the file name from the document metadata is used. Located in the Additional properties group.
Timeout (in seconds)	Number	Yes	Time limit for the upload. Defaults to 30. Located in the Additional properties group.

note

Use Inline Content to build a file (for example, a .json file) directly from process variables without first storing it in the Camunda document store. See inline documents.

If an uploaded document already exists in the container with the same name, it will be overwritten. Depending on the settings made on the Azure Storage Account, the previous version of the document may still be accessible in the file version history.

Output

The connector returns the container, the name of the blob, and a link to it:

{
  "container": "my-container",
  "filename": "invoice.pdf",
  "link": "https://<storage_account_name>.blob.core.windows.net/my-container/invoice.pdf"
}

To get the link to the uploaded blob, use the following FEEL expression as the Result expression:

= {"blobLink": response.link}

Download document

Download a document from a container. Select Download blob in the Operation dropdown.

Input parameters

Property	Type	Required	Description	Example
Blob Storage container	String	Yes	Name of the container that organizes a set of blobs. It must match the container the SAS token was created for.
File name	String	Yes	Name of the document to download.
Response format	Dropdown	Yes	How the downloaded content is returned: Document reference uploads it to the Camunda document store and returns a reference, as text decodes it as a string, and as JSON parses it into a structure. Defaults to Document reference. See return formats.	Defaults to Document reference
Encoding	String	No, defaults to UTF-8	Character set used to decode the content. Shown if Response format is as text.	Defaults to UTF-8

note

as text and as JSON return the content directly in a process variable and are subject to a size guard (approximately 1.5 MiB). Use Document reference for large files. as JSON fails the job when the content is not valid JSON.

Output

The response depends on the Response format.

Document reference returns a reference to a document in the Camunda document store in document:

{
  "document": {
    "storeId": "in-memory",
    "documentId": "8b54b413-b847-4650-b445-de963d5c506d",
    "contentHash": "ed0f7ad835669698a108a32b2a99e89e4f5aea84127fde68df4248b11197b0e5",
    "metadata": {
      "contentType": "application/pdf",
      "size": 2048,
      "fileName": "invoice.pdf"
    },
    "camunda.document.type": "camunda"
  }
}

as text returns the decoded string in content:

{
  "content": "Hello from Azure Blob Storage"
}

as JSON returns the parsed structure in content:

{
  "content": {
    "orderId": "1234",
    "total": 99.5
  }
}

To get the content, use the following FEEL expression as the Result expression, for example with as JSON:

= {"orderId": response.content.orderId}

Troubleshooting

To learn about general error handling in Camunda, see BPMN errors and failing jobs.

Further resources

• Azure Blob Storage documentation
• Document handling