RabbitMQ Queue Latest

Scale applications based on RabbitMQ Queue.

Availability: v1.0+ Maintainer: Microsoft

Suggest a change

Trigger Specification

This specification describes the rabbitmq trigger for RabbitMQ Queue.

triggers:
- type: rabbitmq
  metadata:
    host: amqp://localhost:5672/vhost # Optional. If not specified, it must be done by using TriggerAuthentication.
    protocol: amqp # Specifies protocol to use, either amqp or http. Default value is amqp.
    queueLength: '20' # Optional. Queue length target for HPA. Default: 20 messages
    queueName: testqueue
    # Alternatively, you can use existing environment variables to read configuration from:
    # See details in "Parameter list" section
    hostFromEnv: RABBITMQ_HOST # Optional. You can use this instead of `host` parameter

Parameter list:

  • host: Host of RabbitMQ with format amqp://<host>:<port>/<vhost>. The resolved host should follow a format like amqp://guest:password@localhost:5672/vhost or http://guest:password@localhost:15672/vhostname. When using a username/password consider using hostFromEnv or a TriggerAuthentication.

  • queueName: Name of the queue to read message from. Required.

  • queueLength: Queue length target for HPA. Default is 20. Optional.

  • protocol: Protocol to be used for communication. Either http or amqp. It should correspond with the host value.

Some parameters could be provided using environmental variables, instead of setting them directly in metadata. Here is a list of parameters you can use to retrieve values from environment variables:

  • hostFromEnv: The connection string of the RabbitMQ server, similar to host, but reads it from an environment variable on the scale target.`

💡 Note: host/hostFromEnv has an optional vhost name after the host slash which will be used to scope API request.

Important: if you have unacknowledged messages and want to have these counted for the scaling to happen, make sure to utilize the http REST API interface which allows for these to be counted.

Authentication Parameters

TriggerAuthentication CRD is used to connect and authenticate to RabbitMQ:

  • For AMQP, the URI should look similar to amqp://guest:password@localhost:5672/vhost
  • For HTTP, the URI should look similar to http://guest:password@localhost:15672/vhostname

See the RabbitMQ Ports section for more details on how to configure the ports.

Example

AMQP protocol:

apiVersion: v1
kind: Secret
metadata:
  name: keda-rabbitmq-secret
data:
  host: <AMQP URI connection string> # base64 encoded value of format amqp://guest:password@localhost:5672/vhost
---
apiVersion: keda.sh/v1alpha1
kind: TriggerAuthentication
metadata:
  name: keda-trigger-auth-rabbitmq-conn
  namespace: default
spec:
  secretTargetRef:
    - parameter: host
      name: keda-rabbitmq-secret
      key: host
---
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: rabbitmq-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    name: rabbitmq-deployment
  triggers:
  - type: rabbitmq
    metadata:
      protocol: amqp
      queueName: testqueue
      queueLength: "20"
    authenticationRef:
      name: keda-trigger-auth-rabbitmq-conn

HTTP protocol:

apiVersion: v1
kind: Secret
metadata:
  name: keda-rabbitmq-secret
data:
  host: <HTTP API endpoint> # base64 encoded value of format http://guest:password@localhost:15672/vhostname
---
apiVersion: keda.sh/v1alpha1
kind: TriggerAuthentication
metadata:
  name: keda-trigger-auth-rabbitmq-conn
  namespace: default
spec:
  secretTargetRef:
    - parameter: host
      name: keda-rabbitmq-secret
      key: host
---
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: rabbitmq-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    name: rabbitmq-deployment
  triggers:
  - type: rabbitmq
    metadata:
      protocol: http
      queueName: testqueue
      queueLength: "20"
    authenticationRef:
      name: keda-trigger-auth-rabbitmq-conn


Currently available scalers for KEDA