How does the Monitoring Client get updated?

Auto-update is built into the macOS, Linux and Windows Monitoring Client.

Update Checking

Update Checking can be managed in the Monitoring Client Preference Pane (Mac) or Control Panel (Windows) under the Operation tab.

Auto-update can be controlled via two options within the PreferencePane:

Apply Settings Changes - Allows the server to change settings on the client, required for remote-removal, self-maintenance, and auto-updating.
Install New versions - downloads, validates, and installs new versions of the client itself.

To prevent external code from being automatically installed, disable "Install new versions."

To prevent any external actions from effecting the computer, disable "Apply settings changes." (Not recommended).

The Linux agent does attempt automatic updates by default.

The following command will enable automatic updates and is recommended:

sudo run-client --auto-update true

To disable automatic updates, use the following command:

sudo run-client --auto-update false