@flowfuse/device-agent

FlowFuse Device Agent

This module provides an agent that runs Node-RED instances deployed from the FlowFuse platform.

Prerequisites

• NodeJS v14 or later
• A FlowFuse platform to connect to

Supported Operating Systems

The Device Agent can be installed on most Linux distributions, Windows, and MacOS.

Installing the Device Agent

The Device Agent is published to the public npm repository as @flowfuse/device-agent.

It can be installed as a global npm module. This will ensure the agent command is on the path.

Note: previous versions of the agent were published as @flowforge/flowforge-device-agent.

Linux/MacOS

sudo npm install -g @flowfuse/device-agent

Windows

npm install -g @flowfuse/device-agent

Docker

We publish a Docker container for the Device Agent as flowfuse/device-agent on DockerHub.

When running with the container you will need to mount the device.yml obtained when Registering the device:

docker run --mount type=bind,src=/path/to/device.yml,target=/opt/flowfuse-device/device.yml -p 1880:1880 flowfuse/device-agent:latest

Configuration

The agent configuration is provided by a device.yml file within its working directory.

Configuration directory

By default the agent uses /opt/flowfuse-device or c:\opt\flowfuse-device as its working directory. This can be overridden with the -d/--dir option.

For backwards compatibility with previous versions, the agent will use /opt/flowforge-device if it is exists, unless overridden on the command-line.

NOTE: The device agent will attempt to create the working directory if it is not found, however if an error occurs, the device agent will exit and report a startup error.

Linux/MacOS

sudo mkdir /opt/flowfuse-device
sudo chown -R $USER /opt/flowfuse-device

Windows (run elevated)

mkdir c:\opt\flowfuse-device

device.yml - for a single device

When the device is registered on the FlowFuse platform, a group of configuration details are provided. These can be copied from the platform, downloaded directly as a yml file or pulled from the FlowFuse server using the command issued by the platform when you create a device. More details on this can be found in the FlowFuse documentation.

This file should exist in the working directory as device.yml.

A different config file can be specified with the -c/--config option.

The file must contain the following options (these are the ones provided by FlowFuse)

Required options	Description
deviceId	The id for the device on the FlowFuse platform
token	Access Token to connect to the FF platform
credentialSecret	Key to decrypt the flow credentials
forgeURL	The base url of the FlowFuse platform

To enable MQTT connectivity, the following options are required. They are provided by the platform if MQTT comms are enabled.

MQTT options	Description
brokerURL	The url for the platform broker
brokerUsername	The username to connect with - device:<teamId>:<deviceId>
brokerPassword	The password to connect with

The following options can be added:

Extra options	Description
interval	How often, in seconds, the agent checks in with the platform. Default: 60s
intervalJitter	How much, in seconds, to vary the heartbeat +/- intervalJitter. Default: 10s
moduleCache	If the device can not access npmjs.org then use the node modules cache in module_cache directory. Default false

Node-RED options

The following options are passed through to Node-RED:

Node-RED options	Description
port	The port to listen on. Default: 1880
https	Enable HTTPS. See below for details
httpStatic	Enable serving of static content from a local path

https configuration

The https configuration option can be used to enable HTTPS within Node-RED. The values are passed through to the Node-RED https setting.

The ca, key and cert properties can be used to provide custom certificates and keys. The values should be set to the contents of the certificate/key.

Alternatively, the properties caPath, keyPath and certPath can be used instead to provide absolute paths to files containing the certificates/keys.

https:
   keyPath: /opt/flowfuse-device/certs/key.pem
   certPath: /opt/flowfuse-device/certs/cert.pem
   caPath: /opt/flowfuse-device/certs/ca.pem

httpStatic configuration

This option can be used to serve content from a local directory.

If set to a path, the files in that directory will be served relative to /.

httpStatic: /opt/flowfuse-device/static-content

It is also possible to configure it with a list of directories and the corresponding path they should be served from.

httpStatic:
  - path: /opt/flowfuse-device/static-content/images
    root: /images
  - path: /opt/flowfuse-device/static-content/js
    root: /js

device.yml - for provisioning

When a device should be auto registered on the FlowFuse platform, a group of provisioning configuration details are required. These are generated for you in FlowFuse Team Settings under the Devices tab when you create a provisioning token. These can be copied from the platform, or downloaded directly as a yml file.

This file should be copied into the working directory as device.yml.

A different config file can be specified with the -c/--config option.

The file must contain the following options (these are the ones provided by FlowFuse)

Required options	Description
provisioningName	The name of the token
provisioningTeam	The team this device will be registered to
provisioningToken	Provisioning Token to connect to the FF platform
forgeURL	The base url of the FlowFuse platform

The following options can be added:

Extra options	Description
interval	How often, in seconds, the agent checks in with the platform. Default: 60s
intervalJitter	How much, in seconds, to vary the heartbeat +/- intervalJitter. Default: 10s

Running

If the agent was installed as a global npm module, the command flowfuse-device-agent will be on the path.

If the default working directory and config file are being used, then the agent can be started with:

$ flowfuse-device-agent

For information about the available command-line arguments, run with -h:

Options

  -c, --config file     Device configuration file. Default: device.yml
  -d, --dir dir         Where the agent should store its state. Default: /opt/flowfuse-device
  -i, --interval secs
  -p, --port number
  -m, --moduleCache     Use local npm module cache rather than install

Web UI Options

  -w, --ui            Start the Web UI Server (optional, does not run by default)
  --ui-host string    Web UI server host. Default: (0.0.0.0) (listen on all interfaces)
  --ui-port number    Web UI server port. Default: 1879
  --ui-user string    Web UI username. Required if --ui is specified
  --ui-pass string    Web UI password. Required if --ui is specified
  --ui-runtime mins   Time the Web UI server is permitted to run. Default: 10

Setup command

  -o, --otc string   Setup device using a one time code
  -u, --ff-url url   URL of FlowFuse. Required for setup

Global Options

  -h, --help       print out helpful usage information
  --version        print out version information
  -v, --verbose    turn on debugging output

Running with no access to npmjs.org

By default the Device Agent will try and download the correct version of Node-RED and any nodes required to run the Snapshot that is assigned to run on the device.

If the device is being run on an offline network or security policies prevent the Device Agent from connecting to npmjs.org then it can be configured to use a pre-cached set of modules.

You can enable this mode by adding -m to the command line adding moduleCache: true to the device.yml file. This will cause the Device Agent to load the modules from the module_cache directory in the Device Agents Configuration directory as described above. By default this will be /opt/flowfuse-device/module_cache.

Creating a module cache

To create a suitable module cache, the device must be assigned to an instance. You will need to install the modules on a local device with access to npmjs.org, ensuring you use the same OS and Architecture as your target device, and then copy the modules on to your device.

1. From the Instance Snapshot page, select the snapshot you want to deploy and select the option to download its package.json file.
2. Place this file in an empty directory on your local device.
3. Run npm install to install the modules. This will create a node_modules directory.
4. On your target device, create a directory called module_cache inside the Device Agent Configuration directory.
5. Copy the node_modules directory from your local device to the target device so that it is under the module_cache directory.

Running as a service

An example service file is provided here.

Running the agent with the Web UI enabled

The Device Agents Web UI is provided to enable the user to download a device configuration or a provisioning configuration file. This is an optional feature and is not enabled by default.

To enable the UI, use the -w/--ui option. This will start a web server on the specified host and port. The default host is 0.0.0.0 and the default port is 1879.

When enabling the UI, a username and password must be provided with the --ui-user and --ui-pass options.

The UI will only be available for the duration specified by the --ui-runtime. By default this is 10 minutes. After this time, the web server will be disabled. The application must be restarted to re-enable the UI. You can set this to 0 to disable the timeout. This is not recommended.

Development

Scripts

The following scripts are available:

• npm start - Start the agent
• npm run dev - Build the agent and watch for changes
• npm run lint - Run eslint
• npm run lint:fix - Run eslint and fix any issues
• npm run test - Run all unit tests
• npm run test:lib - Run the unit tests for the lib
• npm run test:frontend - Run the unit tests for the frontend

Changelog

2.4.0: Release

• Add catalogue and npmrc to App bound instances (#246) @hardillb