c8ydm 1.1.0

Cumulocity Device Management Agent

Cumulocity IoT Device Management Reference Agent

Cumulocity Device Management (DM) Reference Agent written in Python3 to demonstrate most of the Device Management Capabilities of Cumulocity IoT

Quick Start

Native

To quickly run the agent natively make sure pyhton 3.7+ and pip is installed on your computer. Manually put the config file and the DM_Agent.json into the /.cumulocity folder in your user folder. For example: "/home/user1/.cumulocity" in Linux or "C:\Users\user1\.cumulocity" in Windows.

Installation

pip install c8ydm

To start the agent run

c8ydm.start

and to stop run

c8ydm.stop

Docker

To quickly run the agent clone this repo somewhere on your disk, make sure that Docker is installed on your computer and run in a Linux Shell:

./start.sh

In Windows Shells like PS or CMD run:

start.bat

The script will build a docker image and starting one instance afterwards. Per default Bootstrapping is used and no other information is necessary. In this case the docker container Id is the device Id which should be entered when registering a device in cumulocity.

You can find it out with:

docker ps

If you want to run the Agent without using docker you need to build and run the Agent manually.

Quick Start Configuration (Docker)

The DM Agent configuration can be either set by changing the agent.ini or setting variables before you build or start the container. For example to use Device Certificates you can use the following ENV Variables.

C8YDM_MQTT_URL=<tenant domain> \
C8YDM_MQTT_CERT_AUTH=TRUE \
C8YDM_MQTT_CLIENT_CERT=<path to cert file> \
C8YDM_MQTT_CLIENT_KEY=<path to key file>

As normal run ./start.sh afterwards.

If you want to use Cloud Remote Access with a VNC server, you can install the server and a desktop environment:

INSTALL_VNC=1 ./start.sh

By default, the docker container runs in background. If you want to run it interactively:

INTERACTIVE=1 ./start.sh

If you don't want to run within docker follow the steps below.

Features

Supported Cumulocity DM Features

Feature	Supported
Device Certificates	Yes
Device Bootstrapping & Registration	Yes
Software Updates (apt)	Yes
Firmware Updates	Yes
Configuration Updates text-based	Yes
Configuration Snapshots	Yes
Device Profiles	Yes
Network	Yes
Device Metrics (CPU, Memory etc.)	Yes
Remote Logfile Requests	Yes
Location Updates	Yes
Remote Shell	Yes
Remote Access (SSH, VNC, Passthrough)	Yes
Hardware Metering (CPU, Memory, HDD)	Yes
Raspberry PI SenseHAT	Yes
Docker Management	Yes

Raspberry PI & SenseHAT Support

The DM Agent can run on a Raspberry PI (3+) with a SenseHAT. It supports:

• Reading out all sensor values of the SenseHAT (Humidity, Temperature, Acceleration, Gyroscope, Compass)
• Display Messages on the LEDs sent via Cumulocity to the Pi (c8y_Message) via Message Widget.
• Generates Events when the Joystick is pressed in different direction.

It is suggested to run the Agent a Service. Use dm-agent.service to install it:

sudo cp ./service/dm-agent.service /etc/systemd/system/
sudo systemctl enable dm-agent.service
sudo systemctl daemon-reload
sudo service dm-agent start 

Configuration

The agent can be configured via the agent.ini which must be placed in

{userFolder}/.cumulocity

When running in docker container the agent.ini can be mounted to the /root/.cumulocity/agent.ini

You can find a reference agent.ini here

Category	Property	Description
mqtt	url	The URL of the Cumulocity MQTT endpoint
mqtt	port	The Port of the Cumulocity MQTT endpoint
mqtt	tls	True when using port 8883, false when using port 1883
mqtt	cert_auth	true when you want use Device Certificates for Device Authentication
mqtt	client_cert	Path to your cert which should be used to for Authentication
mqtt	client_key	Path to your private key for Authentication
mqtt	ping.interval.seconds	Interval in seconds for the mqtt client to send pings to MQTT Broker to keep the connection alive.
agent	name	The prefix name of the Device in Cumulocity. The serial will be attached with a "-" e.g. dm-example-device-1234567.
agent	type	The Device Type in Cumulocity
agent	main.loop.interval.seconds	The interval in seconds sensor data will be forwarded to Cumulocity
agent	requiredinterval	The interval in minutes for Cumulocity to detect that the device is online/offline.
agent	loglevel	The log level to write and print to file/console.

Environment variables

The environment variables which with C8YDM_ prefix are mapped to configuration files. Mapping rules:

• Prefix C8YDM__ means what section the option belongs to
• Upper case letters are mapped to lower case letters
• Double underscore __ is mapped to .

Build

The agent can be build in multiple ways.

Building via pip

To build the agent via pip just run (as a root user, otherwise add "sudo" prior all commands).

pip3 install -r requirements.txt

to install dependencies and afterwards

pip3 install .

to build the agent itself. Please note that in debian/ubuntu you need additionally install

apt install python-apt

via apt.

Continue with chapter Run

Building debian package

In order to build the .deb yourself first install python-stdeb via apt.

apt install python-stdeb

Afterwards run

python setup.py --command-packages=stdeb.command bdist_deb

on the level of the setup.py.

In oder to install the debian package locally run

apt install ./deb_dist/python-c8ydm_0.1-1_all.deb

Continue with chapter Run

Building docker image

To build a docker image you can make use of the provided Dockerfile.

Example:

docker build -t dm-image -f docker/Dockerfile .

Run

Python

Before running the agent some manual steps need to be taken

1. Manually put the config file into {userfolder}/.cumulocity

You can run the agent by executing (as root, otherwise add "sudo")

c8ydm.start

in your console when you used Building via pip to build and install the agent.

apt / Debian package

Before running the agent some manual steps need to be taken

1. Manually put the config file and the DM_Agent.json into ~/.cumulocity folder. ~ stands for the current user folder. The SmartRESTTemplate will be automatically uploaded on first start.

You can run the agent by executing (as root, otherwise add "sudo")

c8ydm.start

in your console when you used Building via deb to build and install the agent.

Docker

You can run the agent by executing

docker run -d -v /var/run/docker.sock:/var/run/docker.sock dm-image

in your console when you used Building Docker Image to build and install the agent.

The config can be mounted the container. Otherwise the default config will be used.

Mass deployment

You can run multiple instances of an container via:

. mass_start.sh 5

where in this example 5 is the number of agent instances.

Develop

Dev Container

The project comes with VS Code devcontainer support. Make sure you use Visual Studio Code in combination with docker. Just open the project in VS Code and click on "Reopen in Dev Container".

In the background the Agent will be build and started. Also a debug/run configuration is provided so you can easilly start/debug the agent within VS Code.

Using certificate authentication

You can generate certificates necessary to certficate authentication, and you can upload the generated root certificate o your tenant's trusted certificate list by executing the scripts like below:

./scripts/generate_cert.sh \
--serial pyagent0001 \
--root-name iot-ca \
--cert-dir /root/.cumulocity/certs \
--cert-name device-cert

./scripts/upload_cert.sh \
--tenant-domain <tenant domain> \
--tenant-id <tenant ID> \
--username <username for the tenant> \
--password <password for the tenant> \
--cert-path /root/.cumulocity/certs/iot-ca.pem \
--cert-name <(arbitrary) displayed name of the root certificate>

After this, you can connect the agent to your tenant using cert authentication (with the serial pyagent0001 in this case).

Testing

With the agent running in the container, execute

./test.sh \
--url <tenant domain> \
--tenant <tenant ID> \
--username <username for the tenant> \
--password <password for the tenant>

to run pytest.

Extending the agent

The agent knows three types of classes that it will automatically load and include from the "agentmodules" directory.

1. Sensors

    class Sensor:
      __metaclass__ = ABCMeta
   
      def __init__(self, serial):
        self.serial = serial
   
      '''
      Returns a list of SmartREST messages. Will be called every iteration of the main loop.
      '''
      @abstractmethod
      def getSensorMessages(self): pass
   

   Sensors are periodically polled by the main loop and published.

2. Listeners

    class Listener:
      __metaclass__ = ABCMeta
   
      def __init__(self, serial, agent):
        self.serial = serial
        self.agent = agent
   
      '''
      Callback that is executed for any operation received
      '''
      @abstractmethod
      def handleOperation(self, message): pass
   
      '''
      Returns a list of supported operations
      '''
      @abstractmethod
      def getSupportedOperations(self): pass
   
      '''
      Returns a list of supported SmartREST templates (X-Ids)
      '''
      @abstractmethod
      def getSupportedTemplates(self): pass
   

   Listeners are called whenever there is a message received on a subscribed topic.

3. Initializers

    class Initializer:
      __metaclass__ = ABCMeta
   
      def __init__(self, serial):
        self.serial = serial
   
      '''
      Returns a list of SmartREST messages. Will be called at the start of the agent
      '''
      @abstractmethod
      def getMessages(self): pass
   

   Initializers are only called once at the start of the agent.

You can take a look at the two example modules for how it can be used.

Log & Configuration

The logfile and configuration can be found in the following directory.

/root/.cumulocity

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These tools are provided as-is and without warranty or support. They do not constitute part of the Software AG product suite. Users are free to use, fork and modify them, subject to the license agreement. While Software AG welcomes contributions, we cannot guarantee to include every contribution in the master project.

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