Skip to main content

DRC INSIGHT – Central Office Services (COS) Installation & Troubleshooting SOP


Audience: IT Administrators / MSP Engineers

Platform: Ubuntu 22.04 / 24.04 + Chromebook environments

Overview

DRC INSIGHT Central Office Services (COS) is a local content hosting system that allows testing devices to retrieve assessment content from a local server instead of the internet.

Key Concept:
COS is a service-based HTTP system, NOT a file share.
Devices do NOT access /opt/CentralOffice directly.

Architecture

Testing Devices
    ↓
DRC INSIGHT App
    ↓
COS Server
    ↓
Local Content (/opt/CentralOffice/content_fs)
    ↓
Fallback → DRC Cloud

Installation (Ubuntu)

1. Update System

sudo apt update && sudo apt upgrade -y

2. Install Required Dependencies

sudo apt install -y \
libxcb-xinerama0 \
libalt-getopt-complete-perl \
libxcb-icccm4 \
libxcb-image0 \
libxcb-keysyms1 \
libxcb-render-util0 \
libxcb-xkb1 \
libxkbcommon-x11-0
Critical: Missing dependencies will cause silent installer failures or services crashing.

3. Fix /tmp Permissions

sudo chmod 1777 /tmp
ls -ld /tmp

4. Clean Previous Install

sudo rm -rf /opt/CentralOffice
sudo rm -f /tmp/coinstaller*.lock

5. Run Installer

chmod +x silent-linux.sh
sudo ./silent-linux.sh

Registration (REQUIRED)

Important: You MUST open the setup URL generated during installation.

This step registers COS with DRC and enables services.

If skipped:

  • Relay fails
  • Contenthosting fails
  • Devices cannot connect

Validate Services

Check Running Services

sudo /opt/CentralOffice/node \
/opt/CentralOffice/setup/node_modules/forever/bin/forever -p /opt/CentralOffice list

Expected:

  • management
  • relay
  • proxy
  • contenthosting

Check Ports

sudo ss -tulnp | grep node

Typical Ports:

  • 55223 – Content Hosting
  • 55224 – Relay
  • 55225 – Proxy

Test Service

curl -I http://127.0.0.1:55223

HTTP 404 is normal and confirms the service is running.

DRC Portal Configuration

Content Management

  • Enable Content Management → ON
  • Select tests (PSSA, Keystone, CDT)
  • Click Update Configuration

Content Hosting

  • Enable Content Hosting → ON
  • Load Balancer → OFF
  • Shared Content Location → OFF
Shared content should only be used in multi-server environments.

Proxy

  • Use Proxy → OFF

Chromebook Configuration

Install App

  • Deploy DRC INSIGHT via Google Admin Console

Register Device

Launch App → Assign Device to ORG Unit → Enter ORG ID

Required Settings

  • Display Scale = 100%
  • Keyboard = US English
  • Same network as COS

Network Requirements

Allowlist

*.drcedirect.com

Ports

  • 80 (HTTP)
  • 443 (HTTPS)

Internal COS Ports

sudo ufw allow 55223/tcp
sudo ufw allow 55224/tcp
sudo ufw allow 55225/tcp

Content Validation

ls -lah /opt/CentralOffice/content_fs
sudo journalctl -u centralofficecontenthosting -f

Troubleshooting

Installer Fails

sudo chmod 1777 /tmp
sudo rm -rf /opt/CentralOffice
sudo ./silent-linux.sh

Only Proxy Running

Cause: COS not registered

Heartbeat Error

CO API - Heartbeat returned undefined

Fix:

  • Complete setup URL
  • Verify internet access
  • Allow DRC domains

Chromebooks Cannot Connect

  • Verify ORG ID
  • Check network
  • Confirm ports open

Validation Checklist

  • [ ] COS services running
  • [ ] Ports listening
  • [ ] Content downloading
  • [ ] Portal configured correctly
  • [ ] Chromebooks registered

Key Takeaways

  • COS is NOT a file server
  • Uses HTTP endpoints
  • Registration is required
  • Content hosting must be enabled

End of SOP

Back to top