mqtt_subscriber (Mosquitto) example

Example use of the MQTT protocol in KasperskyOS.

In this example, an MQTT publisher must be started on the host operating system, and an MQTT subscriber must be started on KasperskyOS. The Subscriber program is an implementation of an MQTT subscriber.

When the example starts and runs successfully, an MQTT subscriber started on KasperskyOS prints a "Got message with topic: my/awesome/topic, payload: hello" message.

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 publisher on the host system, run the following command:

$ mosquitto_pub -t "my/awesome/topic" -m "hello"

Supplied resources

• The directory ./resources/edl contains the Subscriber.edl file, which contains a static description of the Subscriber 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_subscriber

Building and running example

See Building and running examples section.