<a id="connect-azure-functions-connector"></a>

# Azure Functions Sink Connector for Confluent Platform

The Kafka Connect Azure Functions Sink connector integrates Kafka with Azure
Functions.

#### IMPORTANT
<!-- WARNING: THIS IS A SHARED FILE AND THE SOURCE IS LOCATED IN DOCS-COMMON. DO NOT ADD TO ANY OTHER REPO. -->

Effective July 6, 2025, only self-managed connector versions that meet or exceed the minimum version listed on the
[Supported Connector Versions](https://docs.confluent.io/platform/7.8/connect/supported-connector-version.html#supported-connector-versions-till-cp-7-8)
page receive support from Confluent. Older, unsupported connector versions have been removed from Confluent Marketplace and
are no longer available for download.

The connector consumes records from Kafka topic(s) and executes an Azure
Function. Each request sent to Azure Functions contains can contain up to
`max.batch.size` records. The connector can also send many requests
concurrently, set by `max.outstanding.requests`.

The target function must be configured and ready to accept requests with the
following JSON format:

```bash
[
  {
    "key": ...,
    "value": ...,
    "topic": string,
    "partition": <number>,
    "offset": <number>,
    "timestamp": <number>
  },
  ...,
]
```

#### NOTE
The key and value are encoded as follows:

- `String`, `int`, `long`, `float`, `double`, `boolean`, `null` are encoded as-is into JSON.
- `Structs` are converted to JSON and exported *without* the schema.
- `byte[]` is encoded as a base64 `String` and sent as a JSON string.
- Any other Java objects are converted to `String` using `toString()`,
  and then sent as JSON strings.

The connector receives the responses from the Azure Function and writes it to a
result or error topic (set by configurations) depending on the HTTP Response
code. Response code `400` and above are considered errors and anything below
is a success.

The connector attempts to map each response to a single record before producing
it to the corresponding topic. It can receive the responses from the Azure
Function in the following three formats.

1. The first format is JSON:
   ```bash
   [
     {
       "payload": {
         "result": ...,
         "topic": string,
         "partition": <number>,
         "offset": <number>,
       }
     },
     ...
   ]
   ```

   This list can be out of order relative to the order that the records were
   provided. The connector will correctly match the record to the result based
   off its Kafka coordinates. However the list must be one-to-one to the list of
   records that were sent in the request.
2. The second format is a JSON list:
   ```bash
   [
     ...,
     ...,
     ...
   ]
   ```

   As long as the list is one-to-one to the list of records, the list will be
   assumed to be ordered and matched with the corresponding records.
3. The third format can be any format that does not satisfy either of the
   above formats. The connector will report the entire response for each individual
   record (one-to-many correlation).

## Features

The Azure Functions Sink connector includes the following features:

- [At least once delivery](#azure-functions-sink-at-least-once-delivery)
- [Dead Letter Queue](#azure-functions-sink-dead-letter-queue)
- [Multiple tasks](#azure-functions-sink-multiple-tasks)
- [Client-side encryption](#azure-functions-sink-csfle-sm)

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### At least once delivery

This connector guarantees that records from the Kafka topic are delivered at
least once.

<a id="azure-functions-sink-dead-letter-queue"></a>

### Dead Letter Queue

This connector supports the Dead Letter Queue (DLQ) functionality. For
information about accessing and using the DLQ, see [Confluent Platform
Dead Letter Queue](/platform/current/connect/concepts.html#dead-letter-queue).

<a id="azure-functions-sink-multiple-tasks"></a>

### Multiple tasks

The Azure Functions Sink connector supports running one or more tasks. You can
specify the number of tasks in the `tasks.max` configuration parameter. This
can lead to performance gains when multiple files need to be parsed.

<a id="azure-functions-sink-csfle-sm"></a>

### Client-side encryption

This connector supports Client-Side Field Level Encryption (CSFLE) and Client-Side Payload Encryption (CSPE). For more information, see [Manage Client-Side Encryption](https://docs.confluent.io/platform/current/connect/manage-csfle.html).

## Limitations

- The connector does not currently support proxy configuration.

## Install the Azure Functions Connector

You can install this connector by using the [confluent connect
plugin
install](https://docs.confluent.io/confluent-cli/current/command-reference/connect/plugin/confluent_connect_plugin_install.html)
command, or by manually downloading the ZIP file.

### Prerequisites

- You must install the connector on every machine where Connect will run.
- An installation of the latest (`latest`) connector version.

  To install the `latest` connector version, navigate to your Confluent Platform
  installation directory and run the following command:
  ```bash
  confluent connect plugin install confluentinc/kafka-connect-azure-functions:latest
  ```

  You can install a specific version by replacing `latest` with a version
  number as shown in the following example:
  ```bash
  confluent connect plugin install confluentinc/kafka-connect-azure-functions:1.0.0-preview
  ```

### Install the connector manually

[Download and extract the ZIP file](https://www.confluent.io/hub/confluentinc/kafka-connect-azure-functions) for
your connector and then follow the manual connector installation
[instructions](/kafka-connectors/self-managed/userguide.html#connect-installing-plugins).

## License

You can use this connector for a 30-day trial period without a license key.

After 30 days, you must purchase a connector subscription which includes [Confluent enterprise license](/platform/current/installation/license.html#enterprise-subscription-license) keys to subscribers, along with [enterprise-level support](https://www.confluent.io/subscription/) for Confluent Platform and your connectors. If you are a subscriber, you can contact [Confluent Support](https://support.confluent.io/) for more information.

See [Confluent Platform license](connector_config.md#azure-functions-sink-connector-license-config) for license properties
and [License topic configuration](connector_config.md#azure-functions-sink-license-topic-configuration) for information about the
license topic.

## Configuration Properties

For a complete list of configuration properties for this connector, see
[Configuration Reference for Azure Functions Sink Connector for Confluent Platform](connector_config.md#azure-functions-sink-connector-config).

For an example of how to get Kafka Connect connected to [Confluent Cloud](/cloud/current/index.html), see
[Connect Self-Managed Kafka Connect to Confluent Cloud](/cloud/current/cp-component/connect-cloud-config.html#distributed-cluster).

## Quick Start

This quick start uses the Azure Functions Sink connector to consume records and
execute an example Azure Function.

Prerequisites
: - [Confluent Platform](/platform/current/installation/index.html)
  - [Confluent CLI](https://docs.confluent.io/confluent-cli/current/installing.html) (requires separate installation)

1. Before starting the connector, create and deploy an Azure Functions instance.
   * Navigate to the Microsoft [Azure Portal](https://portal.azure.com/).
   * Create a FunctionApp following this [quick start guide](https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-first-azure-function).

   #### IMPORTANT
   Make sure to select the Node.js runtime stack and to create the function in-portal.

   * Copy and paste this code into the `index.js` file in the portal.
     ```javascript
     module.exports = async function (context, req) {
         context.log('JavaScript HTTP trigger function processed a request.');
         context.res = {
             status: 200,
             body: req.body
         };
     };
     ```
   * Copy the function url and function key from the portal and save it for
     later. Azure Functions should now be set up for the connector.

     #### NOTE
     This example function just mirrors the request and sends the request
     body back in the response.
2. Install the connector through the [Confluent Hub Client](/kafka-connectors/self-managed/confluent-hub/client.html).
   ```bash
   # run from your CP installation directory
   confluent connect plugin install confluentinc/kafka-connect-azure-functions:latest
   ```
3. Start Confluent Platform using the [Confluent CLI](https://docs.confluent.io/confluent-cli/current/index.html) commands.
   ```bash
   confluent local start
   ```
4. Produce test data to the `functions-test` topic in Kafka using the
   [Confluent CLI](https://docs.confluent.io/confluent-cli/current/index.html) confluent local produce command.
   ```bash
   echo key1,value1 | confluent local produce functions-test --property parse.key=true --property key.separator=,
   echo key2,value2 | confluent local produce functions-test --property parse.key=true --property key.separator=,
   echo key3,value3 | confluent local produce functions-test --property parse.key=true --property key.separator=,
   ```
5. Create a `azure-functions-sink.json` file with the following contents:
   ```bash
   {
     "name": "azure-functions",
     "config": {
       "topics": "functions-test",
       "tasks.max": "1",
       "connector.class": "io.confluent.connect.azure.functions.AzureFunctionsSinkConnector",
       "key.converter":"org.apache.kafka.connect.storage.StringConverter",
       "value.converter":"org.apache.kafka.connect.storage.StringConverter",
       "confluent.topic.bootstrap.servers": "localhost:9092",
       "confluent.topic.replication.factor": "1",
       "function.url": "<the copied function url>",
       "function.key": "<the copied function key>",
       "reporter.bootstrap.servers": "localhost:9092",
       "reporter.error.topic.name": "test-error",
       "reporter.error.topic.replication.factor": 1,
       "reporter.error.topic.key.format": "string",
       "reporter.error.topic.value.format": "string",
       "reporter.result.topic.name": "test-result",
       "reporter.result.topic.key.format": "string",
       "reporter.result.topic.value.format": "string",
       "reporter.result.topic.replication.factor": 1
     }
   }
   ```
6. Load the Azure Functions Sink connector.
   ```bash
   confluent local load azure-functions --config path/to/azure-functions-sink.json
   ```

   #### IMPORTANT
   Don’t use the [Confluent CLI](https://docs.confluent.io/confluent-cli/current/index.html) commands in
   production environments.
7. Confirm that the connector is in a `RUNNING` state.
   ```bash
   confluent local status azure-functions
   ```
8. Confirm that the messages were delivered to the result topic in Kafka
   ```bash
   confluent local consume test-result --from-beginning
   ```
9. Cleanup resources
   * Delete the connector
     ```bash
     confluent local unload azure-functions
     ```
   * Stop Confluent Platform
     ```bash
     confluent local stop
     ```
   * Delete the created Azure Function in the Azure portal.