Getting started with the Scaleway IoT Hub CLI

Reviewed on 04 November 2024

In this tutorial we will use the API through the Scaleway command line interface CLI. This will show you how to create Hubs and Devices, as well as more advanced features of the Scaleway IoT Hub: Hub Events and Routes.

You can find the API reference documentation at the following link: IoT API

Before you start

To complete the actions presented below, you must have:

A Scaleway account logged into the console
Owner status or IAM permissions allowing you to perform actions in the intended Organization
Installed mosquitto-clients (mqtt client) and jq (json parsing tool) on your computer
Installed and configured the Scaleway CLI

Setting up the hub

The Hub creation is done through the scw iot hub create command, your CLI configuration already includes the project ID, you can optionally set:

A name, with name="my_first_hub". For this tutorial purposes, the name is not important.
A product plan, with product-plan="plan_dedicated".

Save the output to a hub.json file to make it easier later, so we need to tell the CLI to output as json:

scw iot hub create -o json > hub.json
jq < hub.json

The file hub.json will contain come content as like the following example:

{
"id": "b20c3639-9030-496c-a1b2-6feb15846726",
"name": "cli-hub-cocky-hugle",
"status": "enabling",
"product_plan": "plan_shared",
"enabled": true,
"device_count": 0,
"connected_device_count": 0,
"endpoint": "iot.fr-par.scw.cloud",
"disable_events": false,
"events_topic_prefix": "$SCW/events",
"region": "fr-par",
"created_at": "2021-04-26T08:46:33.436Z",
"updated_at": "2021-04-26T08:46:33.436Z",
"project_id": "<your project ID>",
"organization_id": "<your organization ID>",
"enable_device_auto_provisioning": false,
"has_custom_ca": false
}

Poll the hub status until it is ready:

scw iot hub get $(jq -r '.id' hub.json) | grep Status

At some point, the status will switch to ready.

Set up the devices

Now create 2 devices. You just need to provide:

The Hub ID. This is the "id" field from the JSON response received while creating a hub.
(Optional) A name. Again, the name is not important for this tutorial.

Note

As this tutorial aims to be simple and straightforward, the following commands are allowing the device to connect using insecure protocols, such as plain text MQTT or MQTTs without mutual authentication. In production, you should Deny Insecure connections to have the highest level of security. This is done by setting the field allow-insecure to false.

Save the response to a file so we can use the fields later.

scw iot device create \
hub-id=$(jq -r '.id' hub.json) \
allow-insecure=true \
-o json > dev1.json
jq < dev1.json

The file dev1.json should contain something similar to:

{
"device": {
    "id": "0a184d04-aa69-43e5-8fbf-0ee0793aea43",
    "name": "cli-device-pensive-bassi",
    "description": "",
    "status": "enabled",
    "hub_id": "b20c3639-9030-496c-a1b2-6feb15846726",
    "last_activity_at": "1970-01-01T00:00:00Z",
    "is_connected": false,
    "allow_insecure": true,
    "allow_multiple_connections": false,
    "message_filters": {
    "publish": {
        "policy": "reject",
        "topics": []
    },
    "subscribe": {
        "policy": "reject",
        "topics": []
    }
    },
    "created_at": "2021-04-26T09:36:10.708Z",
    "updated_at": "2021-04-26T09:36:10.708Z"
},
"certificate": {
    "crt": "<certificate here>",
    "key": "<certificate key here>"
}
}

Now create a second device:

scw iot device create \
hub-id=$(jq -r '.id' hub.json) \
allow-insecure=true \
-o json > dev2.json
jq < dev2.json

Now that everything is set up, let’s simulate 2 devices and send data.

Setup the subscriber:

# In one terminal
mosquitto_sub \
-h $(jq -r '.endpoint' hub.json) \
-i $(jq -r '.device.id' dev1.json) \
-t mytopic/mysubtopic

Run the publisher:

# In another terminal
mosquitto_pub \
-h $(jq -r '.endpoint' hub.json) \
-i $(jq -r '.device.id' dev2.json) \
-t mytopic/mysubtopic \
-m 'Hello, world!'

You should see the subscriber receive the Hello, world! message.

Setting up TLS mutual authentication

If you require security, you can also connect your device to the Hub using TLS mutual authentication. With this method, the Hub can check the device’s identity, and the device can check the Hub’s identity.

Note

It is possible to connect to the Hub using TLS but without Mutual authentication. In this case, the device certificates are not needed as the Hub does not need to check the device identity. But the Hub certificate will still be needed as your client must check the hub’s identity.

Start by downloading the IoT Hub CA:

curl -sS -O https://iot.s3.nl-ams.scw.cloud/certificates/fr-par/iot-hub-ca.pem
sha1sum iot-hub-ca.pem
# 13cf3e59ed52d4c4b6bc249e85539d5fd5d572fb  iot-hub-ca.pem

Then extract the certificates from the device JSON files, so that the mosquitto clients may use them:

jq -r '.certificate.crt' dev1.json > dev1.crt
jq -r '.certificate.key' dev1.json > dev1.key
jq -r '.certificate.crt' dev2.json > dev2.crt
jq -r '.certificate.key' dev2.json > dev2.key

Run the same test as before, but with the added security:

# In one terminal
mosquitto_sub \
-h $(jq -r '.endpoint' hub.json) -p 8883 \
--cert dev1.crt --key dev1.key --cafile iot-hub-ca.pem \
-i $(jq -r '.device.id' dev1.json) \
-t mytopic/mysubtopic

# In another terminal
mosquitto_pub \
-h $(jq -r '.endpoint' hub.json) -p 8883 \
--cert dev2.crt --key dev2.key --cafile iot-hub-ca.pem \
-i $(jq -r '.device.id' dev2.json) \
-t mytopic/mysubtopic \
-m 'Hello, SECURE world!'

Note

You can mix MQTT and MQTTs clients on the same hub.

You can harness the real power of MQTT Pub/Sub with this blog post: An Introduction to the MQTT protocol.

Getting started with the Scaleway IoT Hub CLI

Before you start

Setting up the hub

Set up the devices

Subscribe and Publish

Setting up TLS mutual authentication