title	RabbitMQ trigger for Azure Functions
description	Learn how to run an Azure Function when a RabbitMQ message is created.
author	cachai2
ms.topic	reference
ms.date	01/21/2022
ms.author	cachai
ms.devlang	csharp
ms.custom	devx-track-extended-java, devx-track-js, devx-track-python
zone_pivot_groups	programming-languages-set-functions-lang-workers

RabbitMQ trigger for Azure Functions overview

Use the RabbitMQ trigger to respond to messages from a RabbitMQ queue.

[!INCLUDE functions-rabbitmq-plans-support-note]

For information on setup and configuration details, see the overview.

Example

::: zone pivot="programming-language-csharp"

[!INCLUDE functions-bindings-csharp-intro-with-csx]

[!INCLUDE functions-in-process-model-retirement-note]

Isolated worker model

:::code language="csharp" source="~/azure-functions-dotnet-worker/samples/Extensions/RabbitMQ/RabbitMQFunction.cs" range="12-23" :::

In-process model

The following example shows a C# function that reads and logs the RabbitMQ message as a RabbitMQ Event:

[FunctionName("RabbitMQTriggerCSharp")]
public static void RabbitMQTrigger_BasicDeliverEventArgs(
    [RabbitMQTrigger("queue", ConnectionStringSetting = "rabbitMQConnectionAppSetting")] BasicDeliverEventArgs args,
    ILogger logger
    )
{
    logger.LogInformation($"C# RabbitMQ queue trigger function processed message: {Encoding.UTF8.GetString(args.Body)}");
}

The following example shows how to read the message as a POCO.

namespace Company.Function
{
    public class TestClass
    {
        public string x { get; set; }
    }

    public class RabbitMQTriggerCSharp{
        [FunctionName("RabbitMQTriggerCSharp")]
        public static void RabbitMQTrigger_BasicDeliverEventArgs(
            [RabbitMQTrigger("queue", ConnectionStringSetting = "rabbitMQConnectionAppSetting")] TestClass pocObj,
            ILogger logger
            )
        {
            logger.LogInformation($"C# RabbitMQ queue trigger function processed message: {pocObj}");
        }
    }
}

Like with JSON objects, an error will occur if the message isn't properly formatted as a C# object. If it is, it's then bound to the variable pocObj, which can be used for what whatever it's needed for.

::: zone-end ::: zone pivot="programming-language-java"

The following Java function uses the @RabbitMQTrigger annotation from the Java RabbitMQ types to describe the configuration for a RabbitMQ queue trigger. The function grabs the message placed on the queue and adds it to the logs.

@FunctionName("RabbitMQTriggerExample")
public void run(
    @RabbitMQTrigger(connectionStringSetting = "rabbitMQConnectionAppSetting", queueName = "queue") String input,
    final ExecutionContext context)
{
    context.getLogger().info("Java HTTP trigger processed a request." + input);
}

::: zone-end
::: zone pivot="programming-language-javascript"

The following example shows a RabbitMQ trigger binding in a function.json file and a JavaScript function that uses the binding. The function reads and logs a RabbitMQ message.

Here's the binding data in the function.json file:

{
    "bindings": [
        {
            "name": "myQueueItem",
            "type": "rabbitMQTrigger",
            "direction": "in",
            "queueName": "queue",
            "connectionStringSetting": "rabbitMQConnectionAppSetting"
        }
    ]
}

Here's the JavaScript script code:

module.exports = async function (context, myQueueItem) {
    context.log('JavaScript RabbitMQ trigger function processed work item', myQueueItem);
};

::: zone-end
::: zone pivot="programming-language-python"

The following example demonstrates how to read a RabbitMQ queue message via a trigger.

A RabbitMQ binding is defined in function.json where type is set to RabbitMQTrigger.

{
    "scriptFile": "__init__.py",
    "bindings": [
        {
            "name": "myQueueItem",
            "type": "rabbitMQTrigger",
            "direction": "in",
            "queueName": "queue",
            "connectionStringSetting": "rabbitMQConnectionAppSetting"
        }
    ]
}

import logging
import azure.functions as func

def main(myQueueItem) -> None:
    logging.info('Python RabbitMQ trigger function processed a queue item: %s', myQueueItem)

::: zone-end
::: zone pivot="programming-language-powershell" PowerShell examples aren't currently available. ::: zone-end
::: zone pivot="programming-language-csharp"

Attributes

Both isolated worker process and in-process C# libraries use RabbitMQTriggerAttribute to define the function, where specific properties of the attribute depend on the extension version.

Extension v2.x+

The attribute's constructor accepts these parameters:

Parameter	Description
QueueName	Name of the queue from which to receive messages.
HostName	This parameter is no longer supported and is ignored. It will be removed in a future version.
ConnectionStringSetting	The name of the app setting that contains the connection string for your RabbitMQ server. This setting only takes an app setting key name, you can't directly set a connection string value. For more information, see Connections.
UserNameSetting	This parameter is no longer supported and is ignored. It will be removed in a future version.
PasswordSetting	This parameter is no longer supported and is ignored. It will be removed in a future version.
Port	Gets or sets the port used. Defaults to 0, which points to the RabbitMQ client's default port setting of `5672`.

Extension v2.x+

The attribute constructor accepts these parameters:

Parameter	Description
QueueName	Name of the queue from which to receive messages.
ConnectionStringSetting	The name of the app setting that contains the connection string for your RabbitMQ server. This setting only takes an app setting key name, you can't directly set a connection string value. For more information, see Connections.
DisableAck	Optional value that defaults to `False`. Set to `True` when message acknowledgements from the service are disabled and are done manually using `RabbitMQMessageActions`.
DisableCertificateValidation	Boolean value that can be set to `true` indicating that certificate validation should be disabled. Default value is `false`. Not recommended for production. Doesn't apply when SSL is disabled.

Extension v1.x

The attribute's constructor accepts these parameters:

Parameter	Description
QueueName	Name of the queue from which to receive messages.
HostName	Hostname of the queue, such as 10.26.45.210. Ignored when using `ConnectStringSetting`.
ConnectionStringSetting	The name of the app setting that contains the connection string for your RabbitMQ server. This setting only takes an app setting key name, you can't directly set a connection string value. For more information, see Connections.
UserNameSetting	Name of the app setting that contains the username to access the queue, such as `UserNameSetting: "%< UserNameFromSettings >%"`. Ignored when using `ConnectStringSetting`.
PasswordSetting	Name of the app setting that contains the password to access the queue, such as `PasswordSetting: "%< PasswordFromSettings >%"`. Ignored when using `ConnectStringSetting`.
Port	Gets or sets the port used. Defaults to 0, which points to the RabbitMQ client's default port setting of `5672`.

Extension v1.x

The attribute's constructor accepts these parameters:

Parameter	Description
QueueName	Name of the queue from which to receive messages.
HostName	Hostname of the queue, such as 10.26.45.210. Ignored when using `ConnectStringSetting`.
ConnectionStringSetting	The name of the app setting that contains the connection string for your RabbitMQ server. This setting only takes an app setting key name, you can't directly set a connection string value. For more information, see Connections.
UserNameSetting	Name of the app setting that contains the username to access the queue, such as `UserNameSetting: "%< UserNameFromSettings >%"`. Ignored when using `ConnectStringSetting`.
PasswordSetting	Name of the app setting that contains the password to access the queue, such as `PasswordSetting: "%< PasswordFromSettings >%"`. Ignored when using `ConnectStringSetting`.
Port	Gets or sets the port used. Defaults to 0, which points to the RabbitMQ client's default port setting of `5672`.

::: zone-end
::: zone pivot="programming-language-java"

Annotations

The RabbitMQTrigger annotation allows you to create a function that runs when a RabbitMQ message is created.

Extension v2.x+

The annotation supports the following configuration options:

Parameter	Description
queueName	Name of the queue from which to receive messages.
connectionStringSetting	The name of the app setting that contains the connection string for your RabbitMQ server. This setting only takes an app setting key name, you can't directly set a connection string value. For more information, see Connections.
disableCertificateValidation	Boolean value that can be set to `true` indicating that certificate validation should be disabled. Default value is `false`. Not recommended for production. Does not apply when SSL is disabled.

Extension v1.x

The annotation supports the following configuration options:

Parameter	Description
queueName	Name of the queue from which to receive messages.
hostName	Hostname of the queue, such as 10.26.45.210. Ignored when using `ConnectStringSetting`.
userNameSetting	Name of the app setting that contains the username to access the queue, such as `UserNameSetting: "%< UserNameFromSettings >%"`. Ignored when using `ConnectStringSetting`.
passwordSetting	Name of the app setting that contains the password to access the queue, such as `PasswordSetting: "%< PasswordFromSettings >%"`. Ignored when using `ConnectStringSetting`.
connectionStringSetting	The name of the app setting that contains the connection string for your RabbitMQ server. This setting only takes an app setting key name, you can't directly set a connection string value. For more information, see Connections.
port	Gets or sets the port used. Defaults to 0, which points to the RabbitMQ client's default port setting of `5672`.

::: zone-end
::: zone pivot="programming-language-javascript,programming-language-python,programming-language-powershell"

Configuration

The following table explains the binding configuration properties that you set in the function.json file.

Extension v2.x+

function.json property	Description
type	Must be set to `RabbitMQTrigger`.
direction	Must be set to `in`.
name	The name of the variable that represents the queue in function code.
queueName	Name of the queue from which to receive messages.
connectionStringSetting	The name of the app setting that contains the connection string for your RabbitMQ server. This setting only takes an app setting key name, you can't directly set a connection string value. For more information, see Connections.
disableCertificateValidation	Boolean value that can be set to `true` indicating that certificate validation should be disabled. Default value is `false`. Not recommended for production. Does not apply when SSL is disabled.

Extension v1.x

function.json property	Description
type	Must be set to `RabbitMQTrigger`.
direction	Must be set to `in`.
name	The name of the variable that represents the queue in function code.
queueName	Name of the queue from which to receive messages.
hostName	Hostname of the queue, such as 10.26.45.210. Ignored when using `connectStringSetting`.
userNameSetting	Name of the app setting that contains the username to access the queue, such as `UserNameSetting: "%< UserNameFromSettings >%"`. Ignored when using `connectStringSetting`.
passwordSetting	Name of the app setting that contains the password to access the queue, such as `PasswordSetting: "%< PasswordFromSettings >%"`. Ignored when using `connectStringSetting`.
connectionStringSetting	The name of the app setting that contains the connection string for your RabbitMQ server. This setting only takes an app setting key name, you can't directly set a connection string value. For more information, see Connections.
port	Gets or sets the port used. Defaults to 0, which points to the RabbitMQ client's default port setting of `5672`.

[!INCLUDE app settings to local.settings.json]

::: zone-end

See the Example section for complete examples.

Usage

::: zone pivot="programming-language-csharp"
The parameter type supported by the RabbitMQ trigger depends on the C# modality used.

Isolated worker model

The RabbitMQ bindings currently support only string and serializable object types when running in an isolated process.

In-process model

The default message type is RabbitMQ Event, and the Body property of the RabbitMQ Event can be read as the types listed below:

An object serializable as JSON - The message is delivered as a valid JSON string.
string
byte[]
POCO - The message is formatted as a C# object. For complete code, see C# example.

::: zone-end
::: zone pivot="programming-language-javascript"
The queue message is available via context.bindings.<NAME> where <NAME> matches the name defined in function.json. If the payload is JSON, the value is deserialized into an object. ::: zone-end

[!INCLUDE functions-rabbitmq-connections]

Dead letter queues

Dead letter queues and exchanges can't be controlled or configured from the RabbitMQ trigger. To use dead letter queues, pre-configure the queue used by the trigger in RabbitMQ. Refer to the RabbitMQ documentation.

Enable Runtime Scaling

In order for the RabbitMQ trigger to scale out to multiple instances, the Runtime Scale Monitoring setting must be enabled.

In the portal, this setting can be found under Configuration > Function runtime settings for your function app.

:::image type="content" source="media/functions-networking-options/virtual-network-trigger-toggle.png" alt-text="VNETToggle":::

In the Azure CLI, you can enable Runtime Scale Monitoring by using this command:

az resource update -resource-group <RESOURCE_GROUP> -name <APP_NAME>/config/web \
    --set properties.functionsRuntimeScaleMonitoringEnabled=1 \
    --resource-type Microsoft.Web/sites

Monitoring a RabbitMQ endpoint

To monitor your queues and exchanges for a certain RabbitMQ endpoint:

Enable the RabbitMQ management plugin
Browse to http://{node-hostname}:15672 and log in with your user name and password.

Send RabbitMQ messages from Azure Functions (Output binding)

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

RabbitMQ trigger for Azure Functions overview

Example

Isolated worker model

In-process model

Attributes

Extension v2.x+

Extension v2.x+

Extension v1.x

Extension v1.x

Annotations

Extension v2.x+

Extension v1.x

Configuration

Extension v2.x+

Extension v1.x

Usage

Isolated worker model

In-process model

Dead letter queues

Enable Runtime Scaling

Monitoring a RabbitMQ endpoint

Related article

FilesExpand file tree

functions-bindings-rabbitmq-trigger.md

Latest commit

History

functions-bindings-rabbitmq-trigger.md

File metadata and controls

RabbitMQ trigger for Azure Functions overview

Example

Attributes

Annotations

Configuration

Usage

Dead letter queues

Enable Runtime Scaling

Monitoring a RabbitMQ endpoint

Related article