This page walks you through the setup steps required to use Cloud IoT Core and introduces you to some key concepts.
(If you've completed the Quickstart, you've already done some of these steps. Review this page to make sure you're ready to use Cloud IoT Core.)
Before you begin
Set up the Google Cloud SDK and gcloud
Install the Google Cloud SDK. Cloud IoT Core requires version 173.0.0 or higher of the SDK.
Run the following command to update the gcloud CLI that's included in the SDK:
gcloud components update
If you're using a Compute Engine VM with the default installation of gcloud, you won't be able to update the components. To enable Cloud IoT Core on a Compute Engine VM, reinstall gcloud by running the following commands:
sudo apt-get remove google-cloud-sdk curl https://sdk.cloud.google.com | bash exec -l $SHELL gcloud init
For more details, see the reference documentation for the gcloud
Introduction to Cloud IoT Core
In order for a device to connect, it must first be registered with Cloud IoT Core. Registration consists of adding a device to a collection (the registry) and defining some essential properties. You can register a device with Cloud Platform Console, gcloud commands, or the REST-style API. For details, see Creating Registries and Devices.
Collectively, the features that allow you to register, monitor, and configure devices are called the device manager.
Protocols (MQTT and HTTP)
Cloud IoT Core supports two protocols for device connection and communication: MQTT and HTTP. Devices communicate with Cloud IoT Core across a "bridge" — either the MQTT bridge or the HTTP bridge. When you create a device registry, you select protocols to enable: MQTT, HTTP, or both.
MQTT is a standard publish/subscribe protocol that is frequently used and supported by embedded devices, and is also common in machine-to-machine interactions.
HTTP is a "connectionless" protocol: with the HTTP bridge, devices do not maintain a connection to Cloud IoT Core. Instead, they send requests and receive responses.
Cloud IoT Core uses public key (or asymmetric) authentication:
- The device uses a private key to sign a JSON Web Token (JWT). The token is passed to Cloud IoT Core as proof of the device's identity.
- The service uses the device public key (uploaded before the JWT is sent) to verify the device's identity.
Device control from the cloud
With Cloud IoT Core, you can control a device by modifying its configuration. A device configuration is an arbitrary, user-defined blob of data that may or may not be structured. If your devices use MQTT, configurations are automatically propagated to them. If your devices connect over HTTP, they must explicitly request configurations.
For details, see the section on configuring devices.