If you have recently deployed VT Writer in an Azure cloud environment and are having issues were scans are not working, it is likely that the Azure monitoring agent that comes with Azure images is the culprit.

This is because the Azure monitoring agent uses the same port as the VT Writer - API Web Worker (8084).

To verify or detect this may the issue, check if the Azure monitoring agent is installed/running.

 systemctl status azuremonitoragent 

If the agent is installed, verify it's running on port 8084. You can do this running:

sudo netstat -tulpn

# Example output of the above command

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State   PID/Program name 
 
tcp      0        0  127.0.0.1:8084  0.0.0.0:*    LISTEN 3456/AzureMonAgent

After verifying that the Azure monitoring agent is installed and running on port 8084 you will need to change the default port for the API Web Worker service. This can be done by editing the visiblethread.env file.

Open the file using a text editor of your choice:

sudo vi /etc/default/visiblethread.env


# Look for the block below and change the port from 8084 to a port not in use.
# In the example below it's changed to 8085.


# Custom API worker tmp directory
API_WORKER_TMPDIR="/tmp"
API_PORT="${API_PORT:-8085}"
API_DOCS_ENDPOINT="${API_DOCS_ENDPOINT:-http://localhost:8085/api/v1/documents}"
API_URL_ENDPOINT="${API_URL_ENDPOINT:-http://localhost:8085/api/v1/webscans}"

After changing the port, restart the service:

sudo systemctl restart vtapi-web-worker

Now, log into the application and try running a scan.

If there is still an issue running scans please contact support@visiblethread.com to open a support ticket. Please provide the application log in the ticket.

# Log location
/opt/visiblethread/readabilityout.log
/var/log/vtapi-web-worker/vtapi-web-worker.log