vRO – start a workflow with AQMP message

Posted on by Jesper Ramsgaard

System to system interaction can be hard. API integrations are a way of doing it, but we can also use a message bus. Actually I think that using a message bus is a very awesome way of doing it, it’s a very loose couple between systems and we can queue multiple things and have the task or messages in RabbitMQ until system is ready to consume the messages.

This is a guide of using vRO to pick up the RabbitMQ message and start a workflow with the payload of the message.

Adding RabbitMQ to vRO:

  • Open vRO legacy client, login
  • Expand Library > AMQP > Configuration
  • Start the workflow Add a broker. This will pair vRO and RabbitMQ.
  • Follow the wizard. I’m using a virtual host, but input all depends on your RabbitMQ config.
Running the workflow “Add a broker” to pair vRO and RabbitMQ.

Subscribe vRO to a RabbitMQ queue:

From the same position in vRO, now run the workflow “Subscribe to queues“. This will make vRO aware of the queue and be able to use it as a trigger.

Subscribing to a RabbitMQ queue.
Give the queue subscription a name.
Choose the broker we added in the section before.
Add the name of the queue from RabbitMQ, must be identical from what the queue name is in RabbitMQ.

Now vRO is monitoring the queue, we are ready to proceed.

Creating a policy:

Now we need to create a policy that can tie the event of a message from RabbitMQ into a starting a workflow.

Navigate to the policy fane in vRO and create a new policy.
Inside the new policy, add a new policy element.
Choose the AMQP:Subscription.
From the popup you can now filter for the queue that you earlier made a subscription on.
Right-click the queue name and chose Add trigger event
Choose onMessage
Holding focus at the “onMessage” event we can choose a workflow that the policy will start on message.
You will need to search, this time its for the workflow that you want to start when there is a message in the queue.
Now we will need to map a variable to the payload of the message that we have received. You need to have an in variable declared as a string in the workflow that you have mapped to.
The in variable from your workflow will show and by double-clicking on the name of the variable you are able to choose the “event.key.body” to it. This will make the payload of the message become a variable for your workflow.

Wrap-up:

That was a lot of screen dumps, I hope it still makes sense.

Now you should make the policy start when vRO starts and for now also start the policy so that you can see it works. The case that is shown in the screen dumps will have a JSON as the message payload, it then sends it to the messageBody variable and then inside the script it will extract the values that it needs in for the workflow to run.

Example of how to parse the JSON to a JavaScript object and afterwards parse the needed parameters over to a new variable. In this case its parameters for a PowerShell script.

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Jesper Ramsgaard

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