EDR Event Forwarder: 'hostname detection failed' Error When Applying Profile

Products

• Carbon Black EDR (formerly Cb Response)
• Carbon Black Hosted EDR (formerly Cb Response Cloud)

Issue/Introduction

• Error seen when attempting to save the profile in the EDR Web UI and the /var/log/cb/integrations/cb-event-forwarder/cb-event-forwarder.startup.log log file:

level=fatal msg="Configuration errors:\n hostname detection failed - set the system hostname or cb_server_url in the event-forwarder configuration file"

Environment

• EDR Event Forwarder: 3.8.1

Cause

• Possible defect in 3.8.1 EDR Event Forwarder.

Resolution

• The hostname is missing from /etc/hosts in the localhost section. 
  • Add a new line at the beginning with the loopback address and your hostname, this should be on a separate line from the current loopback address line and first in the hosts file. 

    127.0.0.1   myhostnamehere
    127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4

  • Restart your network adapter

    sudo systemctl restart network