Simple example showing how to use NATS triggers with Scaleway Functions.
For complete examples of triggers in all function languages, see triggers-getting-started.
The example function is triggered by a message to a NATS topic, and will log the message body.
This example requires Terraform.
Also, NATS must be activated on your project.
The Terraform configuration will create an example function, a NATS account, and a trigger. It will also write the NATS credentials to a file (files/nats-creds).
To authenticate with Scaleway, you can either set up the Scaleway CLI, from which Terraform can extract credentials, or you can export SCW_ACCESS_KEY, SCW_SECRET_KEY and SCW_DEFAULT_PROJECT_ID.
Once auth is set up, you can run:
terraform init
terraform applyYou should be able to see your resources in the Scaleway console:
- NATS accounts can be found in the MnQ section
- Functions can be found in the
triggers-natsnamespace in the Serverless functions section
You can trigger your functions by sending messages to the NATS topic associated to the trigger (triggers-nats-topic). Below is a description of how to do this with our dummy tests/send_messages.py script.
First you need to extract your NATS endpoint from Terraform:
export NATS_ENDPOINT=$(terraform output -raw nats_endpoint)Then you can set up a Python environment in the tests directory, e.g.
cd tests
python3 -m venv venv
source venv/bin/activate
pip3 install -r requirements.txtNow you can run the send_messages.py script to send a message to the NATS topic:
python3 send_messages.pyIn your Cockpit, you can access the logs from your NATS topics and functions.
Navigate from your Cockpit to Grafana, and find the Serverless Functions Logs dashboard. There you should see logs from your function, printing the body of the NATS message.
To delete all the resources used in this example, you can run the following from the root of the project:
terraform destroy