Docker

Click on the Disabled switch to activate the docker service.

This feature allows to run custom containers on the UTM and does not currently offer any additional configuration option besides activating the docker service.

A container allows to run microservices on a device, in parallel to the functionalities provided by the UTM. Sample scenarios in which the docker functionality may prove useful include:

  • Deploying Node-Red applications. A company that developed a data processing logic software with the help of Node-Red, can deploy it easily on all devices in its production facilities.

  • Developing a custom Python application for a particular device and having it running on other similar devices, that are located at customer sites all around the world.

Once the docker functionality has been activated on the UTM, starting a new container only requires to access the CLI and run a command. For example, Endian set up an image to run an OPC-UA server on an UTM; to create a container and run it requires only to issue the following command:

docker run --name opcua-server -ti -p 4840:4840 -d endiansrl/opcua-demo

After the command has successfully been executed, it suffices to
connect from any OPC-UA client to the following address to browse
the sample data contained in the image.

opc.tcp://GREENIP:4840

Replace GREENIP with the actual IP of the GREEN zone.

Settings

The Docker runtime establishes trust of a remote image registry based on the validity of its Transport Layer Security (TLS) certificate. If your cluster uses a self-signed certificate, Docker will consider it “insecure” by default. Here you can add your own Insecure Registries should you wish to utilize them. They can be added in three ways which is intiated by clicking + Add button:

IP address

Enter the IP address and port of the insecure registry.

CIDR block

Enter the network subnet in CIDR format of the insecure registry.

Note

When using the CIDR block, Docker will assume any valid IP within the specified block can be treated as an insecure registry.

Hostname

Enter the hostname and port of the insecure registry.

See also

Additional resources about docker can be found online:

Docker official documentation, including architecture and overview of the whole engine.

Docker curriculum, an extensive and detailed tutorial.

An interesting and open framework for IoT edge computing is the Linux EdgeX Foundry, which is also a repository of resources and solutions for IoT deployment.