Cumulocity with thin-edge demo

Agenda:

• Cumulocity overview
• Quick tour of cumulocity portal
• Thin-edge overview
• Demo

Cumulocity

Cumulocity is a cloud platform centered on IoT needs with a focus on ease of use and rapid deployment. As a cloud service it is limited compared to Azure or AWS for example, mainly offering services needed for device integration, management and data processing. Docs

Cumulocity does support tenant hierarchies, i.e. enterprise tenants which have subtenants under them. Also they offer the option to run cumulocity cloud on customer's own datacenter or server, in which case all data is presumably fully under customer's control.

Agents

Devices connect to the cloud via agents. Agents can be run on premises on the device, a gateway etc, or on the cloud. Cloud agents are mainly intended for scenarios where device is "closed" and only allows for a predefined way to connect.

Agents support child device hierarchies (communication hierarchy)

Agents can communicate with the cloud with HTTP(S) or MQTT protocols. Agents send measurements, events and alarms and receive operations. They are queued on both ends and support low availability networks.

Cloud

The cloud is quite limited compared to a fully fledged cloud service like Azure or AWS. It offers prebuilt web applications for administration, cockpit, device management, digital twin management etc. in the portal. These can be extended or branded (say, making a new widget for cockpit), although they seem to be Angular JS based and at least their SDK is deprecated.

Some supported features:

• Hosting web applications that can use whatever HTML5/javascript-based frameworks you want.
• Hosting backend services running as docker based microservices on cumulocity-hosted kubernetes.
• Real-time processing of incoming measurements, events and alarms.
  • They offer a no-code solution that can do some things
  • More interestingly, they have the so called Apama event processing language for more complex processing
    • Resembles java, but is limited

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thin-edge.io

Open source (Apache 2.0 license) cloud-agonstic IoT framework written in Rust, designed for resource constrained edge devices. Docs Github

Architecture in a nutshell:

• Central MQTT bus for all communication (Mosquitto)
• Data mapper translates thin edge MQTT messages to cloud formats. At least Cumulocity, Azure and AWS supported out of the box.
• Agent executes commands like software management, firmware updates, configuration updates etc.
• Custom services interact via MQTT as well, for example publishing to the topic te/device/main///m/ is picked up by the data mapper, translated to the cloud specific formats and sent to the cloud(s)

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Demo

Installing thin-edge

1. Install thin edge: sudo apt-get install tedge-full or wget -O - thin-edge.io/install.sh | sh -s

2. Create device certificate sudo tedge cert create --device-id raspi_01

3. Configure cloud endpoint sudo tedge config set c8y.url demo.cumulocity.com

4. Upload certificate to cloud tedge cert upload c8y you need to copy/paste username and password for c8y account

Tip: Make sure the certificate uploaded correctly by navigating to device management -> management -> trusted certificates in cumulocity portal

5. Connect: sudo tedge connect c8y

Tip: Test the mqtt connection by creating a measurement: tedge mqtt pub te/device/main///m/ '{"test_measurement": 5.0}'

Measurements

An example script for Philips Hue motion sensor measurements

Simple motion sensor example

Device control

Thin edge offers a set of operations it can do out of the box. Default operations can be overridden if desired and new ones added.

pi@raspberrypi:~ $ ls /etc/tedge/operations/c8y/
c8y_DownloadConfigFile  c8y_LogfileRequest  c8y_RemoteAccessConnect  c8y_Restart  c8y_SoftwareUpdate  c8y_UploadConfigFile

Custom operations

1. Add smart rest template to trigger operation: import smart-rest-template.json to cumulocity smart rest templates

2. Configure the template in thin edge: sudo tedge config set c8y.smartrest.templates simple_light_control

3. Reconnect thin edge to synchronize inventory: sudo tedge reconnect c8y

Tip: you can verify the template is configured by checking the file less /etc/tedge/mosquitto-conf/c8y-bridge.conf It should contain lines:

topic s/uc/simple_light_control out 2 c8y/ ""
topic s/dc/simple_light_control in 2 c8y/ ""

Tip: You can also verify the message is delivered correctly by listening to the cloud topic: tedge mqtt sub 'c8y#' To send an operation, use c8y cli: c8y identity get --name raspi_01 | c8y operations create --description "test" --template "{'set_light':{lightid:1,on:true}}"

4. Create custom operations handler on thin edge: Add a file to /etc/tedge/operations/c8y as the tedge user: sudo -u tedge touch /etc/tedge/operations/c8y/set_light Edit the set_light and save

5. Create the script that will be executed and make sure it has permissions

Tip: check file permissions: ls -l, set execute permissions for all users: chmod a+x simpleLightControl.sh

6. Thin edge needs to restart to register custom command: sudo tedge reconnect c8y

7. Create an operation (see above) and veryfiy that the script ran. It should produce a log file, configured inside the script.

Tip: since the light control script pipes output to a log file, make sure the tedge user has rights to write it.

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Tools

go-c8y-cli unofficial CLI tool

Command line interface for cumulocity API: https://goc8ycli.netlify.app

Supports piping, for example:

c8y operations list --status PENDING | c8y operations update --status FAILED

Needs to start a session to the cloud to work. For connecting first time use:

c8y sessions create \
    --host "https://mytenant.eu-latest.cumulocity.com" \
    --username "myUser@me.com" \
    --type dev

For subsequent reconnects:

eval $(c8y sessions set --shell bash)