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DRC INSIGHT Central Office Services (COS) Installation and Troubleshooting Ubuntu Linux

DRC INSIGHT - COS Troubleshooting SOP

Purpose:Audience: ResolveIT theAdministrators most/ commonMSP LinuxEngineers

COS

Platform: installation,Ubuntu service,22.04 and/ 24.04 + Chromebook issues.environments

IssueOverview

1

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
Installer

2. FailsInstall 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 Stopsservices Earlycrashing.

Symptoms:

3.

    Fix No/tmp usable COS services Installer exits quickly Lock file or temp errors

    Fix:

    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

    IssueRegistration 2 - Only Proxy Runs(REQUIRED)

    Symptoms:Important:
      You foreverMUST list shows only proxy relay and contenthosting do not stay running

      Likely Cause:

        Registration not completed Configuration not generated correctly

        Fix:

          Completeopen the setup URL fromgenerated installationduring installation.

          This step registers COS with DRC and enables services.

          If skipped:

            Relay fails RestartContenthosting COSfails servicesDevices cannot connect

            IssueValidate 3 - Relay Heartbeat ErrorServices

            Error:

            Check 

            CO API - Heartbeat returned undefined

            Likely Cause:

              Registration incomplete DRC API not reachable Upstream filtering or SSL inspection interfering

              Fix:

                Complete registration Verify internet connectivity Allow required DRC URLs and ports

                Issue 4 -Running Services Show "active (exited)"

                This can be normal. COS uses forever to launch Node services in the background, so the systemd wrapper may show as exited while the Node processes continue running.

                Use this command as the truth source:

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

                Issue 5 - Chromebooks Cannot Connect

                Check:Expected:

                • ORG Unit ID entered correctlymanagement
                • Chromebook can reach COS network pathrelay
                • Display size is 100%proxy
                • Keyboard is US English
                Portal configuration is greencontenthosting

                Check

                Issue 6 - Content Does Not Download

                Check:

                  Content Management enabled Content Hosting enabled Shared Content OFF for single server Correct test programs selected

                  Useful Commands

                  Ports 
                  # Check runtime services
sudo /opt/CentralOffice/node \
/opt/CentralOffice/setup/node_modules/forever/bin/forever -p /opt/CentralOffice list

# Check ports
sudo ss -tulnp | grep node
                  #

                  Typical CheckPorts:

                    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 directoryshould 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
                                # Follow content hosting logs 
                                sudo journalctl -u centralofficecontenthosting -f

# Follow relay logs
sudo journalctl -u centralofficerelay -f

                                SupportTroubleshooting

                                Contacts

                                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

                                    • DRC[ PA] CustomerCOS Service:services (800) 451-7849running
                                    • DRC[ Status] Page:Ports https://status.drcedirect.com/PAlistening
                                    [ ] 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 Troubleshooting SOP

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