mqtt_publisher (Mosquitto) example

Example use of the MQTT protocol in KasperskyOS.

In this example, an MQTT subscriber must be started on the host operating system, and an MQTT publisher must be started on KasperskyOS. The Publisher program is an implementation of an MQTT publisher that publishes the current time with a 5-second interval.

When the example starts and runs successfully, an MQTT subscriber started on the host operating system prints a "received PUBLISH" message with a "datetime" topic.

The example also demonstrates the use of various virtual file systems (VFS) in a single solution:

• The VfsNet program is used for working with the network.
• The VfsSdCardFs program is used to work with the file system.

The CMake system, which is included with KasperskyOS Community Edition, is used to build and run the example.

Starting Mosquitto

To run this example, a Mosquitto MQTT broker must be installed and started on the host system. To install and start Mosquitto, run the following commands:

$ sudo apt install mosquitto mosquitto-clients

$ sudo /etc/init.d/mosquitto start

To start an MQTT subscriber on the host system, run the following command:

$ mosquitto_sub -d -t "datetime"

Supplied resources

• The directory ./resources/edl contains the Publisher.edl file, which contains a static description of the Publisher program.
• The directory ./resources/hdd/etc contains the configuration files for the VfsNet, Dhcpcd and Ntpd programs: hosts, dhcpcd.conf and ntp.conf, respectively.

Example files

The code of the example and build scripts are available at the following path:

/opt/KasperskyOS-Community-Edition-<version>/examples/mqtt_publisher

Building and running example

See Building and running examples section.