docs(examples): add NATS triggers in triggers-getting-started (#66)

* docs(examples): add NATS triggers in triggers-getting-started

* fix: add missing comma

* docs: update README

.github/workflows/go-function-offline-testing.yml

@@ -14,7 +14,7 @@ jobs:
       matrix:
         tests: [
           { directory: 'cors-go', go-version: '1.19' },
-          { directory: 'go-hello-world', go-version: '1.20' }
+          { directory: 'go-hello-world', go-version: '1.20' },
           { directory: 'go-mnq-sqs-publish', go-version: '1.18' },
           { directory: 'go-upload-file-s3-multipart', go-version: '1.20' }
         ]

functions/triggers-getting-started/README.md

@@ -1,20 +1,22 @@
 # Triggers Getting Started
 
-Simple starter examples that showcase using SQS triggers in all Scaleway Functions supported languages.
+Simple starter examples that showcase using SQS triggers or NATS triggers in all Scaleway Functions supported languages.
 
-In each example, a function is triggered by a SQS queue with a message containing a number. The function will then print the factorial of this number to the logs.
+In each example, a function is triggered by a SQS queue or a NATS subject with a message containing a number.
+The function will then print the factorial of this number to the logs.
 
 ## Requirements
 
 This example requires [Terraform](https://www.scaleway.com/en/docs/tutorials/terraform-quickstart/).
 
-Also, SQS **must** be [activated](https://www.scaleway.com/en/docs/serverless/messaging/how-to/get-started/#how-to-activate-sqs-or-sns) on your project.
+Also,[SQS](https://www.scaleway.com/en/docs/serverless/messaging/how-to/get-started/#how-to-activate-sqs-or-sns) **must** be activated on your project,
+and you **must** have a [NATS account](https://www.scaleway.com/en/docs/serverless/messaging/how-to/get-started/#how-to-create-a-nats-account).
 
 ## Setup
 
 The Terraform configuration will deploy a function for each language, showing how to use triggers with each language.
 
-It will also create a SQS queue per function to trigger it.
+It will also create a SQS queue per function and a NATS account to trigger it.
 
 After exporting `SCW_ACCESS_KEY`, `SCW_SECRET_KEY` and `SCW_DEFAULT_PROJECT_ID` variables (for authentication), you can:
 
@@ -25,22 +27,31 @@ terraform apply
 
 You should be able to see your resources in the Scaleway console:
 
-- Queues can be found in the [MnQ section](https://console.scaleway.com/messaging/protocols/fr-par/sqs/queues)
+- Queues can be found in the Messaging section under [SQS](https://console.scaleway.com/messaging/protocols/fr-par/sqs/queues)
+- NATS account can be found in the Messaging section under [NATS](https://console.scaleway.com/messaging/protocols/fr-par/nats/accounts)
 - Functions can be found in the `triggers-getting-started` namespace in the [Serverless functions section](https://console.scaleway.com/functions/namespaces)
 
 ## Running
 
-You can trigger your functions by sending messages to any of the associated SQS queues. Below is a description of how to do this with our dummy `tests/send_messages.py` script.
+You can trigger your functions by sending messages to any of the associated SQS queues or NATS subject.
+Below is a description of how to do this with our dummy `tests/send_[sqs|nats]_messages.py` script.
 
 ### Setup
 
-First you need to expose your SQS access and secret keys:
+First, you need to expose your SQS access and secret keys:
 
 ```console
 export AWS_ACCESS_KEY_ID=$(terraform output -raw sqs_access_key)
 export AWS_SECRET_ACCESS_KEY=$(terraform output -raw sqs_secret_key)
 ```
 
+Or configure NATS credentials:
+
+```console
+export NATS_CREDS_FILE=$(terraform output -raw creds_file)
+export SUBJECT_NAME=$(terraform output -raw subject_name)
+```
+
 Then you can set up a Python environment in the `tests` directory, e.g.
 
 ```console
@@ -52,17 +63,24 @@ pip3 install -r requirements.txt
 
 ### Sending messages
 
-Now you can run the `send_messages.py` script to send a message to the SQS queue of each function:
+Now you can run the `send_sqs_messages.py` script to send a message to the SQS queue of each function:
+
+```console
+python3 send_sqs_messages.py
+```
+
+Or you can run the `send_nats_messages.py` script to send a message to the NATS subject:
 
 ```console
-python3 send_messages.py
+python3 send_nats_messages.py
 ```
 
 ### Viewing function logs
 
-In your [Cockpit](https://console.scaleway.com/cockpit), you can access the logs from your queues and functions.
+In your [Cockpit](https://console.scaleway.com/cockpit), you can access the logs from your queues, NATS account and functions.
 
-Navigate from your Cockpit to Grafana, and find the `Serverless Functions Logs` dashboard. There you should see something like the following, showing that your functions were triggered by messages on the queues:
+Navigate from your Cockpit to Grafana, and find the `Serverless Functions Logs` dashboard. 
+There you should see something like the following, showing that your functions were triggered by messages on the queues/NATS subject:
 
 ```console
 ...
@@ -84,7 +102,9 @@ If you don't see these logs, make sure you have selected one of the "triggers ge
 
 ### Costs
 
-Configuring and managing triggers is free, you only pay for the execution of your functions. For more information, please consult the [Scaleway Serverless pricing](https://www.scaleway.com/en/pricing/?tags=serverless). You will also be billed for the SQS queue usage when sending messages to it.
+Configuring and managing triggers is free, you only pay for the execution of your functions. 
+For more information, please consult the [Scaleway Serverless pricing](https://www.scaleway.com/en/pricing/?tags=serverless). 
+You will also be billed for the SQS queue usage and NATS account when sending messages to it.
 
 ## Cleanup
 

functions/triggers-getting-started/main.tf

@@ -26,6 +26,7 @@ locals {
       handler = "handler"
     }
   }
+  subject_name = "triggers-nats-factorial"
 }
 
 resource "scaleway_function_namespace" "main" {
@@ -59,21 +60,23 @@ resource "scaleway_function" "main" {
   min_scale = 0
 }
 
-resource "scaleway_mnq_sqs_queue" "main" {
+resource "scaleway_function_trigger" "main_sqs" {
   for_each = local.functions
 
-  name         = "factorial-requests-${each.key}"
-
-  access_key = scaleway_mnq_sqs_credentials.main.access_key
-  secret_key = scaleway_mnq_sqs_credentials.main.secret_key
+  function_id = scaleway_function.main[each.key].id
+  name        = "sqs-on-factorial-request"
+  sqs {
+    queue = scaleway_mnq_sqs_queue.main[each.key].name
+  }
 }
 
-resource "scaleway_function_trigger" "main" {
+resource "scaleway_function_trigger" "main_nats" {
   for_each = local.functions
 
   function_id = scaleway_function.main[each.key].id
-  name        = "on-factorial-request"
-  sqs {
-    queue        = scaleway_mnq_sqs_queue.main[each.key].name
+  name        = "nats-on-factorial-request"
+  nats {
+    account_id = scaleway_mnq_nats_account.main.id
+    subject    = local.subject_name
   }
 }

functions/triggers-getting-started/nats.tf

@@ -0,0 +1,13 @@
+resource "scaleway_mnq_nats_account" "main" {
+  name = "nats-account"
+}
+
+resource "scaleway_mnq_nats_credentials" "main" {
+  account_id = scaleway_mnq_nats_account.main.id
+  name       = "triggers-nats"
+}
+
+resource "local_sensitive_file" "nats" {
+  filename = "triggers-nats.creds"
+  content  = scaleway_mnq_nats_credentials.main.file
+}

functions/triggers-getting-started/outputs.tf

@@ -1,9 +1,17 @@
 output "sqs_access_key" {
-  value = scaleway_mnq_sqs_credentials.main.access_key
+  value     = scaleway_mnq_sqs_credentials.main.access_key
   sensitive = true
 }
 
 output "sqs_secret_key" {
   value     = scaleway_mnq_sqs_credentials.main.secret_key
   sensitive = true
 }
+
+output "subject_name" {
+  value = local.subject_name
+}
+
+output "creds_file" {
+  value = local_sensitive_file.nats.filename
+}

functions/triggers-getting-started/sqs.tf

@@ -0,0 +1,17 @@
+resource "scaleway_mnq_sqs_credentials" "main" {
+  name = "triggers-getting-started"
+  permissions {
+    can_publish = true
+    can_receive = true
+    can_manage  = true
+  }
+}
+
+resource "scaleway_mnq_sqs_queue" "main" {
+  for_each = local.functions
+
+  name = "factorial-requests-${each.key}"
+
+  access_key = scaleway_mnq_sqs_credentials.main.access_key
+  secret_key = scaleway_mnq_sqs_credentials.main.secret_key
+}

functions/triggers-getting-started/tests/requirements.txt

@@ -2,3 +2,5 @@
 boto3<1.28.81
 botocore<1.31.81
 requests~=2.31.0
+nats-py==2.6.0
+nkeys==0.1.0

functions/triggers-getting-started/tests/send_nats_messages.py

@@ -0,0 +1,24 @@
+import os
+
+import asyncio
+import nats
+
+MAX_FACTORIAL_REQUESTS = 20
+
+# Credentials file generated by Terraform
+NATS_CREDS_FILE = os.environ["NATS_CREDS_FILE"]
+NATS_ENDPOINT_URL = "nats://nats.mnq.fr-par.scaleway.com:4222"
+SUBJECT_NAME = os.environ["NATS_SUBJECT"]
+
+async def send_nats():
+    nc = await nats.connect(NATS_ENDPOINT_URL, user_credentials=NATS_CREDS_FILE)
+
+    print(f"Sending 0..{MAX_FACTORIAL_REQUESTS} factorial requests to {SUBJECT_NAME}...")
+    for i in range(MAX_FACTORIAL_REQUESTS):
+        await nc.publish(SUBJECT_NAME, f"{i}".encode())
+
+    await nc.close()
+
+
+if __name__ == "__main__":
+    asyncio.run(send_nats())